nrf52832 central and peripheral string send issue

hi destiny98 i also working on sending string from peripheral to central but central device not able to receive it and show the same message every time, here i attach code snippet, please guide me to resolve this issue.

another thing is that i am use ble_app_hrs_c for central device and ble_app_hrs for peripheral device and make modification in it as i need, here i attach my both code also.

/**
 * Copyright (c) 2014 - 2021, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
/** @example examples/ble_peripheral/ble_app_hrs/main.c
 *
 * @brief Heart Rate Service Sample Application main file.
 *
 * This file contains the source code for a sample application using the Heart Rate service
 * (and also Battery and Device Information services). This application uses the
 * @ref srvlib_conn_params module.
 */

//=========================================Modify Peripheral Code=================================================================

#include "app_error.h"
#include "app_timer.h"
#include "ble.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_bas.h"
#include "ble_conn_params.h"
#include "ble_conn_state.h"
#include "ble_dis.h"
#include "ble_err.h"
#include "ble_hci.h"
#include "ble_hrs.h"
#include "ble_srv_common.h"
#include "bsp_btn_ble.h"
#include "fds.h"
#include "nordic_common.h"
#include "nrf.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_lesc.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdm.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "sensorsim.h"
#include <stdint.h>
#include <string.h>

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define DEVICE_NAME "PR_007"                    /**< Name of device. Will be included in the advertising data. */
#define MANUFACTURER_NAME "NordicSemiconductor" /**< Manufacturer. Will be passed to Device Information Service. */
#define APP_ADV_INTERVAL 300                    /**< The advertising interval (in units of 0.625 ms. This value corresponds to 187.5 ms). */

#define APP_ADV_DURATION 18000 /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define APP_BLE_CONN_CFG_TAG 1  /**< A tag identifying the SoftDevice BLE configuration. */
#define APP_BLE_OBSERVER_PRIO 3 /**< Application's BLE observer priority. You shouldn't need to modify this value. */

#define BATTERY_LEVEL_MEAS_INTERVAL APP_TIMER_TICKS(2000) /**< Battery level measurement interval (ticks). */
#define MIN_BATTERY_LEVEL 81                              /**< Minimum simulated battery level. */
#define MAX_BATTERY_LEVEL 100                             /**< Maximum simulated 7battery level. */
#define BATTERY_LEVEL_INCREMENT 1                         /**< Increment between each simulated battery level measurement. */

#define HEART_RATE_MEAS_INTERVAL APP_TIMER_TICKS(1000) /**< Heart rate measurement interval (ticks). */
#define MIN_HEART_RATE 140                             /**< Minimum heart rate as returned by the simulated measurement function. */
#define MAX_HEART_RATE 300                             /**< Maximum heart rate as returned by the simulated measurement function. */
#define HEART_RATE_INCREMENT 10                        /**< Value by which the heart rate is incremented/decremented for each call to the simulated measurement function. */

#define RR_INTERVAL_INTERVAL APP_TIMER_TICKS(300) /**< RR interval interval (ticks). */
#define MIN_RR_INTERVAL 100                       /**< Minimum RR interval as returned by the simulated measurement function. */
#define MAX_RR_INTERVAL 500                       /**< Maximum RR interval as returned by the simulated measurement function. */
#define RR_INTERVAL_INCREMENT 1                   /**< Value by which the RR interval is incremented/decremented for each call to the simulated measurement function. */

#define SENSOR_CONTACT_DETECTED_INTERVAL APP_TIMER_TICKS(5000) /**< Sensor Contact Detected toggle interval (ticks). */

#define MIN_CONN_INTERVAL MSEC_TO_UNITS(400, UNIT_1_25_MS) /**< Minimum acceptable connection interval (0.4 seconds). */
#define MAX_CONN_INTERVAL MSEC_TO_UNITS(650, UNIT_1_25_MS) /**< Maximum acceptable connection interval (0.65 second). */
#define SLAVE_LATENCY 0                                    /**< Slave latency. */
#define CONN_SUP_TIMEOUT MSEC_TO_UNITS(4000, UNIT_10_MS)   /**< Connection supervisory timeout (4 seconds). */

#define FIRST_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(5000) /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(30000) /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT 3                       /**< Number of attempts before giving up the connection parameter negotiation. */

#define LESC_DEBUG_MODE 0 /**< Set to 1 to use LESC debug keys, allows you to use a sniffer to inspect traffic. */

#define SEC_PARAM_BOND 1                               /**< Perform bonding. */
#define SEC_PARAM_MITM 0                               /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC 1                               /**< LE Secure Connections enabled. */
#define SEC_PARAM_KEYPRESS 0                           /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES BLE_GAP_IO_CAPS_NONE /**< No I/O capabilities. */
#define SEC_PARAM_OOB 0                                /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE 7                       /**< Minimum encryption key size. */
#define SEC_PARAM_MAX_KEY_SIZE 16                      /**< Maximum encryption key size. */

#define DEAD_BEEF 0xDEADBEEF /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

BLE_HRS_DEF(m_hrs);                       /**< Heart rate service instance. */
BLE_BAS_DEF(m_bas);                       /**< Structure used to identify the battery service. */
NRF_BLE_GATT_DEF(m_gatt);                 /**< GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                   /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);       /**< Advertising module instance. */
APP_TIMER_DEF(m_battery_timer_id);        /**< Battery timer. */
APP_TIMER_DEF(m_heart_rate_timer_id);     /**< Heart rate measurement timer. */
APP_TIMER_DEF(m_rr_interval_timer_id);    /**< RR interval timer. */
APP_TIMER_DEF(m_sensor_contact_timer_id); /**< Sensor contact detected timer. */

static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID; /**< Handle of the current connection. */
static bool m_rr_interval_enabled = true;                /**< Flag for enabling and disabling the registration of new RR interval measurements (the purpose of disabling this is just to test sending HRM without RR interval data. */

static sensorsim_cfg_t m_battery_sim_cfg;         /**< Battery Level sensor simulator configuration. */
static sensorsim_state_t m_battery_sim_state;     /**< Battery Level sensor simulator state. */
static sensorsim_cfg_t m_heart_rate_sim_cfg;      /**< Heart Rate sensor simulator configuration. */
static sensorsim_state_t m_heart_rate_sim_state;  /**< Heart Rate sensor simulator state. */
static sensorsim_cfg_t m_rr_interval_sim_cfg;     /**< RR Interval sensor simulator configuration. */
static sensorsim_state_t m_rr_interval_sim_state; /**< RR Interval sensor simulator state. */

static ble_uuid_t m_adv_uuids[] = /**< Universally unique service identifiers. */
    {
        {BLE_UUID_HEART_RATE_SERVICE, BLE_UUID_TYPE_BLE},
        {BLE_UUID_BATTERY_SERVICE, BLE_UUID_TYPE_BLE},
        {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE}};

/**@brief Callback function for asserts in the SoftDevice.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num   Line number of the failing ASSERT call.
 * @param[in] file_name  File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t *p_file_name) {
  app_error_handler(DEAD_BEEF, line_num, p_file_name);
}

/**@brief Clear bond information from persistent storage.
 */
static void delete_bonds(void) {
  ret_code_t err_code;

  NRF_LOG_INFO("Erase bonds!");

  err_code = pm_peers_delete();
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for starting advertising.
 */
void advertising_start(bool erase_bonds) {
  if (erase_bonds == true) {
    delete_bonds();
    // Advertising is started by PM_EVT_PEERS_DELETE_SUCCEEDED event.
  } else {
    ret_code_t err_code;

    err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);
  }
}

/**@brief Function for handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const *p_evt) {
  pm_handler_on_pm_evt(p_evt);
  pm_handler_disconnect_on_sec_failure(p_evt);
  pm_handler_flash_clean(p_evt);

  switch (p_evt->evt_id) {
  case PM_EVT_PEERS_DELETE_SUCCEEDED:
    advertising_start(false);
    break;

  default:
    break;
  }
}

/**@brief Function for performing battery measurement and updating the Battery Level characteristic
 *        in Battery Service.
 */
static void battery_level_update(void) {
  ret_code_t err_code;
  uint8_t battery_level;

  battery_level = (uint8_t)sensorsim_measure(&m_battery_sim_state, &m_battery_sim_cfg);

  err_code = ble_bas_battery_level_update(&m_bas, battery_level, BLE_CONN_HANDLE_ALL);
  if ((err_code != NRF_SUCCESS) &&
      (err_code != NRF_ERROR_INVALID_STATE) &&
      (err_code != NRF_ERROR_RESOURCES) &&
      (err_code != NRF_ERROR_BUSY) &&
      (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)) {
    APP_ERROR_HANDLER(err_code);
  }
}

/**@brief Function for handling the Battery measurement timer timeout.
 *
 * @details This function will be called each time the battery level measurement timer expires.
 *
 * @param[in] p_context  Pointer used for passing some arbitrary information (context) from the
 *                       app_start_timer() call to the timeout handler.
 */
static void battery_level_meas_timeout_handler(void *p_context) {
  UNUSED_PARAMETER(p_context);
  battery_level_update();
}

/**@brief Function for handling the Heart rate measurement timer timeout.
 *
 * @details This function will be called each time the heart rate measurement timer expires.
 *          It will exclude RR Interval data from every third measurement.
 *
 * @param[in] p_context  Pointer used for passing some arbitrary information (context) from the
 *                       app_start_timer() call to the timeout handler.
 */
static void heart_rate_meas_timeout_handler(void *p_context) {
  ret_code_t err_code;
  char message[] = "hello slave";
  uint16_t length = strlen(message);

  ble_gatts_hvx_params_t hvx_params = {
      .handle = m_hrs.hrm_handles.value_handle, // Use the correct value handle
      .type = BLE_GATT_HVX_NOTIFICATION,        // Notification type
      .offset = 0,
      .p_len = &length,             // Pointer to message length
      .p_data = (uint8_t *)message, // Pointer to the message data
  };

  err_code = sd_ble_gatts_hvx(m_conn_handle, &hvx_params);
  if (err_code == NRF_SUCCESS) {
    NRF_LOG_INFO("Message sent: %s", message);
  } else {
    NRF_LOG_ERROR("Failed to send message: 0x%x", err_code);
  }
}

/**@brief Function for handling the RR interval timer timeout.
 *
 * @details This function will be called each time the RR interval timer expires.
 *
 * @param[in] p_context  Pointer used for passing some arbitrary information (context) from the
 *                       app_start_timer() call to the timeout handler.
 */
static void rr_interval_timeout_handler(void *p_context) {
  UNUSED_PARAMETER(p_context);

  if (m_rr_interval_enabled) {
    uint16_t rr_interval;

    rr_interval = (uint16_t)sensorsim_measure(&m_rr_interval_sim_state,
        &m_rr_interval_sim_cfg);
    ble_hrs_rr_interval_add(&m_hrs, rr_interval);
    rr_interval = (uint16_t)sensorsim_measure(&m_rr_interval_sim_state,
        &m_rr_interval_sim_cfg);
    ble_hrs_rr_interval_add(&m_hrs, rr_interval);
    rr_interval = (uint16_t)sensorsim_measure(&m_rr_interval_sim_state,
        &m_rr_interval_sim_cfg);
    ble_hrs_rr_interval_add(&m_hrs, rr_interval);
    rr_interval = (uint16_t)sensorsim_measure(&m_rr_interval_sim_state,
        &m_rr_interval_sim_cfg);
    ble_hrs_rr_interval_add(&m_hrs, rr_interval);
    rr_interval = (uint16_t)sensorsim_measure(&m_rr_interval_sim_state,
        &m_rr_interval_sim_cfg);
    ble_hrs_rr_interval_add(&m_hrs, rr_interval);
    rr_interval = (uint16_t)sensorsim_measure(&m_rr_interval_sim_state,
        &m_rr_interval_sim_cfg);
    ble_hrs_rr_interval_add(&m_hrs, rr_interval);
  }
}

/**@brief Function for handling the Sensor Contact Detected timer timeout.
 *
 * @details This function will be called each time the Sensor Contact Detected timer expires.
 *
 * @param[in] p_context  Pointer used for passing some arbitrary information (context) from the
 *                       app_start_timer() call to the timeout handler.
 */
static void sensor_contact_detected_timeout_handler(void *p_context) {
  static bool sensor_contact_detected = false;

  UNUSED_PARAMETER(p_context);

  sensor_contact_detected = !sensor_contact_detected;
  ble_hrs_sensor_contact_detected_update(&m_hrs, sensor_contact_detected);
}

/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module. This creates and starts application timers.
 */
static void timers_init(void) {
  ret_code_t err_code;

  // Initialize timer module.
  err_code = app_timer_init();
  APP_ERROR_CHECK(err_code);

  // Create timers.
  err_code = app_timer_create(&m_battery_timer_id,
      APP_TIMER_MODE_REPEATED,
      battery_level_meas_timeout_handler);
  APP_ERROR_CHECK(err_code);

  err_code = app_timer_create(&m_heart_rate_timer_id,
      APP_TIMER_MODE_REPEATED,
      heart_rate_meas_timeout_handler);
  APP_ERROR_CHECK(err_code);

  err_code = app_timer_create(&m_rr_interval_timer_id,
      APP_TIMER_MODE_REPEATED,
      rr_interval_timeout_handler);
  APP_ERROR_CHECK(err_code);

  err_code = app_timer_create(&m_sensor_contact_timer_id,
      APP_TIMER_MODE_REPEATED,
      sensor_contact_detected_timeout_handler);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for the GAP initialization.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void) {
  ret_code_t err_code;
  ble_gap_conn_params_t gap_conn_params;
  ble_gap_conn_sec_mode_t sec_mode;

  BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

  err_code = sd_ble_gap_device_name_set(&sec_mode,
      (const uint8_t *)DEVICE_NAME,
      strlen(DEVICE_NAME));
  APP_ERROR_CHECK(err_code);

  err_code = sd_ble_gap_appearance_set(BLE_APPEARANCE_HEART_RATE_SENSOR_HEART_RATE_BELT);
  APP_ERROR_CHECK(err_code);

  memset(&gap_conn_params, 0, sizeof(gap_conn_params));

  gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
  gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
  gap_conn_params.slave_latency = SLAVE_LATENCY;
  gap_conn_params.conn_sup_timeout = CONN_SUP_TIMEOUT;

  err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
  APP_ERROR_CHECK(err_code);
}

/**@brief GATT module event handler.
 */
static void gatt_evt_handler(nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_t const *p_evt) {
  if (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED) {
    NRF_LOG_INFO("GATT ATT MTU on connection 0x%x changed to %d.",
        p_evt->conn_handle,
        p_evt->params.att_mtu_effective);
  }

  ble_hrs_on_gatt_evt(&m_hrs, p_evt);
}

/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void) {
  ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error) {
  APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for initializing services that will be used by the application.
 *
 * @details Initialize the Heart Rate, Battery and Device Information services.
 */
static void services_init(void) {
  ret_code_t err_code;
  ble_hrs_init_t hrs_init;
  ble_bas_init_t bas_init;
  ble_dis_init_t dis_init;
  nrf_ble_qwr_init_t qwr_init = {0};
  uint8_t body_sensor_location;

  // Initialize Queued Write Module.
  qwr_init.error_handler = nrf_qwr_error_handler;

  err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
  APP_ERROR_CHECK(err_code);

  // Initialize Heart Rate Service.
  body_sensor_location = BLE_HRS_BODY_SENSOR_LOCATION_FINGER;

  memset(&hrs_init, 0, sizeof(hrs_init));

  hrs_init.evt_handler = NULL;
  hrs_init.is_sensor_contact_supported = false;
  hrs_init.p_body_sensor_location = &body_sensor_location;

  // Here the sec level for the Heart Rate Service can be changed/increased.
  hrs_init.hrm_cccd_wr_sec = SEC_OPEN;
  hrs_init.bsl_rd_sec = SEC_OPEN;

  err_code = ble_hrs_init(&m_hrs, &hrs_init);
  APP_ERROR_CHECK(err_code);

  // Initialize Battery Service.
  memset(&bas_init, 0, sizeof(bas_init));

  bas_init.evt_handler = NULL;
  bas_init.support_notification = true;
  bas_init.p_report_ref = NULL;
  bas_init.initial_batt_level = 100;

  // Here the sec level for the Battery Service can be changed/increased.
  bas_init.bl_rd_sec = SEC_OPEN;
  bas_init.bl_cccd_wr_sec = SEC_OPEN;
  bas_init.bl_report_rd_sec = SEC_OPEN;

  err_code = ble_bas_init(&m_bas, &bas_init);
  APP_ERROR_CHECK(err_code);

  // Initialize Device Information Service.
  memset(&dis_init, 0, sizeof(dis_init));

  ble_srv_ascii_to_utf8(&dis_init.manufact_name_str, (char *)MANUFACTURER_NAME);

  dis_init.dis_char_rd_sec = SEC_OPEN;

  err_code = ble_dis_init(&dis_init);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing the sensor simulators.
 */
static void sensor_simulator_init(void) {
  m_battery_sim_cfg.min = MIN_BATTERY_LEVEL;
  m_battery_sim_cfg.max = MAX_BATTERY_LEVEL;
  m_battery_sim_cfg.incr = BATTERY_LEVEL_INCREMENT;
  m_battery_sim_cfg.start_at_max = true;

  sensorsim_init(&m_battery_sim_state, &m_battery_sim_cfg);

  m_heart_rate_sim_cfg.min = MIN_HEART_RATE;
  m_heart_rate_sim_cfg.max = MAX_HEART_RATE;
  m_heart_rate_sim_cfg.incr = HEART_RATE_INCREMENT;
  m_heart_rate_sim_cfg.start_at_max = false;

  sensorsim_init(&m_heart_rate_sim_state, &m_heart_rate_sim_cfg);

  m_rr_interval_sim_cfg.min = MIN_RR_INTERVAL;
  m_rr_interval_sim_cfg.max = MAX_RR_INTERVAL;
  m_rr_interval_sim_cfg.incr = RR_INTERVAL_INCREMENT;
  m_rr_interval_sim_cfg.start_at_max = false;

  sensorsim_init(&m_rr_interval_sim_state, &m_rr_interval_sim_cfg);
}

/**@brief Function for starting application timers.
 */
static void application_timers_start(void) {
  ret_code_t err_code;

  // Start application timers.
  // err_code = app_timer_start(m_battery_timer_id, BATTERY_LEVEL_MEAS_INTERVAL, NULL);
  // APP_ERROR_CHECK(err_code);

  err_code = app_timer_start(m_heart_rate_timer_id, HEART_RATE_MEAS_INTERVAL, NULL);
  APP_ERROR_CHECK(err_code);

  err_code = app_timer_start(m_rr_interval_timer_id, RR_INTERVAL_INTERVAL, NULL);
  APP_ERROR_CHECK(err_code);

  err_code = app_timer_start(m_sensor_contact_timer_id, SENSOR_CONTACT_DETECTED_INTERVAL, NULL);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module which
 *          are passed to the application.
 *          @note All this function does is to disconnect. This could have been done by simply
 *                setting the disconnect_on_fail config parameter, but instead we use the event
 *                handler mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t *p_evt) {
  ret_code_t err_code;

  if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED) {
    err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
    APP_ERROR_CHECK(err_code);
  }
}

/**@brief Function for handling a Connection Parameters error.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error) {
  APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void) {
  ret_code_t err_code;
  ble_conn_params_init_t cp_init;

  memset(&cp_init, 0, sizeof(cp_init));

  cp_init.p_conn_params = NULL;
  cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
  cp_init.next_conn_params_update_delay = NEXT_CONN_PARAMS_UPDATE_DELAY;
  cp_init.max_conn_params_update_count = MAX_CONN_PARAMS_UPDATE_COUNT;
  cp_init.start_on_notify_cccd_handle = m_hrs.hrm_handles.cccd_handle;
  cp_init.disconnect_on_fail = false;
  cp_init.evt_handler = on_conn_params_evt;
  cp_init.error_handler = conn_params_error_handler;

  err_code = ble_conn_params_init(&cp_init);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void) {
  ret_code_t err_code;

  err_code = bsp_indication_set(BSP_INDICATE_IDLE);
  APP_ERROR_CHECK(err_code);

  // Prepare wakeup buttons.
  err_code = bsp_btn_ble_sleep_mode_prepare();
  APP_ERROR_CHECK(err_code);

  // Go to system-off mode (this function will not return; wakeup will cause a reset).
  err_code = sd_power_system_off();
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt) {
  ret_code_t err_code;

  switch (ble_adv_evt) {
  case BLE_ADV_EVT_FAST:
    NRF_LOG_INFO("Fast advertising.");
    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_ADV_EVT_IDLE:
    sleep_mode_enter();
    break;

  default:
    break;
  }
}

/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const *p_ble_evt, void *p_context) {
  ret_code_t err_code;

  switch (p_ble_evt->header.evt_id) {
  case BLE_GAP_EVT_CONNECTED:
    // NRF_LOG_INFO("Connected.");
    NRF_LOG_INFO("Connected. Hello_I_am_Central_Device!!");
    err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
    APP_ERROR_CHECK(err_code);
    m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
    APP_ERROR_CHECK(err_code);
    err_code = pm_conn_secure(p_ble_evt->evt.gap_evt.conn_handle, false);
    if (err_code != NRF_ERROR_BUSY) {
      APP_ERROR_CHECK(err_code);
    }
    break;

  case BLE_GAP_EVT_DISCONNECTED:
    NRF_LOG_INFO("Disconnected, reason %d.",
        p_ble_evt->evt.gap_evt.params.disconnected.reason);
    m_conn_handle = BLE_CONN_HANDLE_INVALID;
    break;

  case BLE_GAP_EVT_PHY_UPDATE_REQUEST: {
    NRF_LOG_DEBUG("PHY update request.");
    ble_gap_phys_t const phys =
        {
            .rx_phys = BLE_GAP_PHY_AUTO,
            .tx_phys = BLE_GAP_PHY_AUTO,
        };
    err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
    APP_ERROR_CHECK(err_code);
  } break;

  case BLE_GATTC_EVT_TIMEOUT:
    // Disconnect on GATT Client timeout event.
    NRF_LOG_DEBUG("GATT Client Timeout.");
    err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
        BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_GATTS_EVT_TIMEOUT:
    // Disconnect on GATT Server timeout event.
    NRF_LOG_DEBUG("GATT Server Timeout.");
    err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
        BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
    NRF_LOG_DEBUG("BLE_GAP_EVT_SEC_PARAMS_REQUEST");
    break;

  case BLE_GAP_EVT_AUTH_KEY_REQUEST:
    NRF_LOG_INFO("BLE_GAP_EVT_AUTH_KEY_REQUEST");
    break;

  case BLE_GAP_EVT_LESC_DHKEY_REQUEST:
    NRF_LOG_INFO("BLE_GAP_EVT_LESC_DHKEY_REQUEST");
    break;

  case BLE_GAP_EVT_AUTH_STATUS:
    NRF_LOG_INFO("BLE_GAP_EVT_AUTH_STATUS: status=0x%x bond=0x%x lv4: %d kdist_own:0x%x kdist_peer:0x%x",
        p_ble_evt->evt.gap_evt.params.auth_status.auth_status,
        p_ble_evt->evt.gap_evt.params.auth_status.bonded,
        p_ble_evt->evt.gap_evt.params.auth_status.sm1_levels.lv4,
        *((uint8_t *)&p_ble_evt->evt.gap_evt.params.auth_status.kdist_own),
        *((uint8_t *)&p_ble_evt->evt.gap_evt.params.auth_status.kdist_peer));
    break;

  default:
    // No implementation needed.
    break;
  }
}

/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void) {
  ret_code_t err_code;

  err_code = nrf_sdh_enable_request();
  APP_ERROR_CHECK(err_code);

  // Configure the BLE stack using the default settings.
  // Fetch the start address of the application RAM.
  uint32_t ram_start = 0;
  err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
  APP_ERROR_CHECK(err_code);

  // Enable BLE stack.
  err_code = nrf_sdh_ble_enable(&ram_start);
  APP_ERROR_CHECK(err_code);

  // Register a handler for BLE events.
  NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}

/**@brief Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
void bsp_event_handler(bsp_event_t event) {
  ret_code_t err_code;

  switch (event) {
  case BSP_EVENT_SLEEP:
    sleep_mode_enter();
    break;

  case BSP_EVENT_DISCONNECT:
    err_code = sd_ble_gap_disconnect(m_conn_handle,
        BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    if (err_code != NRF_ERROR_INVALID_STATE) {
      APP_ERROR_CHECK(err_code);
    }
    break;

  case BSP_EVENT_WHITELIST_OFF:
    // if (m_conn_handle == BLE_CONN_HANDLE_INVALID)
    //{
    if (m_conn_handle == BLE_CONN_HANDLE_INVALID) {
      NRF_LOG_WARNING("Invalid connection handle. Cannot send message.");
      return;
      err_code = ble_advertising_restart_without_whitelist(&m_advertising);
      if (err_code != NRF_ERROR_INVALID_STATE) {
        APP_ERROR_CHECK(err_code);
      }
    }
    break;

  default:
    break;
  }
}

/**@brief Function for the Peer Manager initialization.
 */
static void peer_manager_init(void) {
  ble_gap_sec_params_t sec_param;
  ret_code_t err_code;

  err_code = pm_init();
  APP_ERROR_CHECK(err_code);

  memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

  // Security parameters to be used for all security procedures.
  sec_param.bond = SEC_PARAM_BOND;
  sec_param.mitm = SEC_PARAM_MITM;
  sec_param.lesc = SEC_PARAM_LESC;
  sec_param.keypress = SEC_PARAM_KEYPRESS;
  sec_param.io_caps = SEC_PARAM_IO_CAPABILITIES;
  sec_param.oob = SEC_PARAM_OOB;
  sec_param.min_key_size = SEC_PARAM_MIN_KEY_SIZE;
  sec_param.max_key_size = SEC_PARAM_MAX_KEY_SIZE;
  sec_param.kdist_own.enc = 1;
  sec_param.kdist_own.id = 1;
  sec_param.kdist_peer.enc = 1;
  sec_param.kdist_peer.id = 1;

  err_code = pm_sec_params_set(&sec_param);
  APP_ERROR_CHECK(err_code);

  err_code = pm_register(pm_evt_handler);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing the Advertising functionality.
 */
static void advertising_init(void) {
  ret_code_t err_code;
  ble_advertising_init_t init;

  memset(&init, 0, sizeof(init));

  init.advdata.name_type = BLE_ADVDATA_FULL_NAME;
  init.advdata.include_appearance = true;
  init.advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
  init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
  init.advdata.uuids_complete.p_uuids = m_adv_uuids;

  init.config.ble_adv_fast_enabled = true;
  init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
  init.config.ble_adv_fast_timeout = APP_ADV_DURATION;

  init.evt_handler = on_adv_evt;

  err_code = ble_advertising_init(&m_advertising, &init);
  APP_ERROR_CHECK(err_code);

  ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}

/**@brief Function for initializing buttons and leds.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
 */
static void buttons_leds_init(bool *p_erase_bonds) {
  ret_code_t err_code;
  bsp_event_t startup_event;

  err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
  APP_ERROR_CHECK(err_code);

  err_code = bsp_btn_ble_init(NULL, &startup_event);
  APP_ERROR_CHECK(err_code);

  *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}

/**@brief Function for initializing the nrf log module.
 */
static void log_init(void) {
  ret_code_t err_code = NRF_LOG_INIT(NULL);
  APP_ERROR_CHECK(err_code);

  NRF_LOG_DEFAULT_BACKENDS_INIT();
}

/**@brief Function for initializing power management.
 */
static void power_management_init(void) {
  ret_code_t err_code;
  err_code = nrf_pwr_mgmt_init();
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void) {
  ret_code_t err_code;

  err_code = nrf_ble_lesc_request_handler();
  APP_ERROR_CHECK(err_code);

  if (NRF_LOG_PROCESS() == false) {
    nrf_pwr_mgmt_run();
  }
}

/**@brief Function for application main entry.
 */
int main(void) {
  bool erase_bonds;

  // Initialize.
  log_init();
  timers_init();
  buttons_leds_init(&erase_bonds);
  power_management_init();
  ble_stack_init();
  gap_params_init();
  gatt_init();
  advertising_init();
  services_init();
  sensor_simulator_init();
  conn_params_init();
  peer_manager_init();

  // Start execution.
  NRF_LOG_INFO("Heart Rate Sensor example started.");
  application_timers_start();
  advertising_start(erase_bonds);

  // Enter main loop.
  for (;;) {
    idle_state_handle();
  }
}



/**
 * Copyright (c) 2014 - 2021, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
/**
 * @brief BLE Heart Rate Collector application main file.
 *
 * This file contains the source code for a sample heart rate collector.
 */

//====================================================Central Modify Code========================================================

#include "app_error.h"
#include "app_timer.h"
#include "app_util.h"
#include "ble.h"
#include "ble_bas_c.h"
#include "ble_conn_state.h"
#include "ble_db_discovery.h"
#include "ble_hci.h"
#include "ble_hrs_c.h"
#include "ble_srv_common.h"
#include "bsp_btn_ble.h"
#include "fds.h"
#include "nordic_common.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_lesc.h"
#include "nrf_ble_scan.h"
#include "nrf_fstorage.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdm.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#define APP_BLE_CONN_CFG_TAG 1 /**< A tag identifying the SoftDevice BLE configuration. */

#define APP_BLE_OBSERVER_PRIO 3 /**< Application's BLE observer priority. You shouldn't need to modify this value. */
#define APP_SOC_OBSERVER_PRIO 1 /**< Applications' SoC observer priority. You shouldn't need to modify this value. */

#define LESC_DEBUG_MODE 0 /**< Set to 1 to use LESC debug keys, allows you to use a sniffer to inspect traffic. */

#define SEC_PARAM_BOND 1                               /**< Perform bonding. */
#define SEC_PARAM_MITM 0                               /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC 1                               /**< LE Secure Connections enabled. */
#define SEC_PARAM_KEYPRESS 0                           /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES BLE_GAP_IO_CAPS_NONE /**< No I/O capabilities. */
#define SEC_PARAM_OOB 0                                /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE 7                       /**< Minimum encryption key size in octets. */
#define SEC_PARAM_MAX_KEY_SIZE 16                      /**< Maximum encryption key size in octets. */

#define SCAN_DURATION_WITELIST 3000 /**< Duration of the scanning in units of 10 milliseconds. */

//#define TARGET_UUID                 BLE_UUID_HEART_RATE_SERVICE         /**< Target device uuid that application is looking for. */

#define CUSTOM_SERVICE_UUID 0x03, 0xB8, 0x0E, 0x5A, 0xED, 0xE8, 0x4B, 0x33, 0xA7, 0x51, 0x6C, 0xE3, 0x4E, 0xC4, 0xC7, 0x00
#define CUSTOM_CHARACTERISTIC_UUID 0x77, 0x72, 0xE5, 0xDB, 0x38, 0x68, 0x41, 0x12, 0xA1, 0xA9, 0xF2, 0x66, 0x9D, 0x10, 0x6B, 0xF3

// The descriptor UUID 0x2902 is a 16-bit UUID for the Client Characteristic Configuration Descriptor
#define CCCD_UUID 0x2902

// Define the target UUID as your custom service UUID
#define TARGET_UUID CUSTOM_SERVICE_UUID

static ble_uuid128_t custom_service_uuid = {
    .uuid128 = {CUSTOM_SERVICE_UUID}};

static ble_uuid128_t custom_characteristic_uuid = {
    .uuid128 = {CUSTOM_CHARACTERISTIC_UUID}};

// The CCCD UUID is already defined in the SDK, you can use BLE_UUID_DESCRIPTOR_CLIENT_CHAR_CONFIG

/**@brief Macro to unpack 16bit unsigned UUID from octet stream. */
#define UUID16_EXTRACT(DST, SRC) \
  do {                           \
    (*(DST)) = (SRC)[1];         \
    (*(DST)) <<= 8;              \
    (*(DST)) |= (SRC)[0];        \
  } while (0)

NRF_BLE_GQ_DEF(m_ble_gatt_queue, /**< BLE GATT Queue instance. */
    NRF_SDH_BLE_CENTRAL_LINK_COUNT,
    NRF_BLE_GQ_QUEUE_SIZE);
BLE_HRS_C_DEF(m_hrs_c);          /**< Structure used to identify the heart rate client module. */
BLE_BAS_C_DEF(m_bas_c);          /**< Structure used to identify the Battery Service client module. */
NRF_BLE_GATT_DEF(m_gatt);        /**< GATT module instance. */
BLE_DB_DISCOVERY_DEF(m_db_disc); /**< DB discovery module instance. */
NRF_BLE_SCAN_DEF(m_scan);        /**< Scanning module instance. */

static uint16_t m_conn_handle;           /**< Current connection handle. */
static bool m_whitelist_disabled;        /**< True if whitelist has been temporarily disabled. */
static bool m_memory_access_in_progress; /**< Flag to keep track of ongoing operations on persistent memory. */

/**< Scan parameters requested for scanning and connection. */
static ble_gap_scan_params_t const m_scan_param =
    {
        .active = 0x01,
#if (NRF_SD_BLE_API_VERSION > 7)
        .interval_us = NRF_BLE_SCAN_SCAN_INTERVAL * UNIT_0_625_MS,
        .window_us = NRF_BLE_SCAN_SCAN_WINDOW * UNIT_0_625_MS,
#else
        .interval = NRF_BLE_SCAN_SCAN_INTERVAL,
        .window = NRF_BLE_SCAN_SCAN_WINDOW,
#endif // (NRF_SD_BLE_API_VERSION > 7)
        .filter_policy = BLE_GAP_SCAN_FP_WHITELIST,
        .timeout = SCAN_DURATION_WITELIST,
        .scan_phys = BLE_GAP_PHY_1MBPS,
};

/**@brief Names which the central applications will scan for, and which will be advertised by the peripherals.
 *  if these are set to empty strings, the UUIDs defined below will be used
 */
static char const m_target_periph_name[] = "PR_007"; /**< If you want to connect to a peripheral using a given advertising name, type its name here. */
static bool is_connect_per_addr = false;             /**< If you want to connect to a peripheral with a given address, set this to true and put the correct address in the variable below. */

static ble_gap_addr_t const m_target_periph_addr =
    {
        /* Possible values for addr_type:
           BLE_GAP_ADDR_TYPE_PUBLIC,
           BLE_GAP_ADDR_TYPE_RANDOM_STATIC,
           BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE,
           BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_NON_RESOLVABLE. */
        .addr_type = BLE_GAP_ADDR_TYPE_RANDOM_STATIC,
        .addr = {0x8D, 0xFE, 0x23, 0x86, 0x77, 0xD9}};

static void scan_start(void);

/**@brief Function for asserts in the SoftDevice.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num     Line number of the failing ASSERT call.
 * @param[in] p_file_name  File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t *p_file_name) {
  app_error_handler(0xDEADBEEF, line_num, p_file_name);
}

/**@brief Function for handling the Heart Rate Service Client and Battery Service Client errors.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void service_error_handler(uint32_t nrf_error) {
  APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for handling database discovery events.
 *
 * @details This function is callback function to handle events from the database discovery module.
 *          Depending on the UUIDs that are discovered, this function should forward the events
 *          to their respective services.
 *
 * @param[in] p_event  Pointer to the database discovery event.
 */
static void db_disc_handler(ble_db_discovery_evt_t *p_evt) {
  ble_hrs_on_db_disc_evt(&m_hrs_c, p_evt);
  ble_bas_on_db_disc_evt(&m_bas_c, p_evt);
}

/**@brief Function for handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const *p_evt) {
  pm_handler_on_pm_evt(p_evt);
  pm_handler_disconnect_on_sec_failure(p_evt);
  pm_handler_flash_clean(p_evt);

  switch (p_evt->evt_id) {
  case PM_EVT_PEERS_DELETE_SUCCEEDED:
    // Bonds are deleted. Start scanning.
    scan_start();
    break;

  default:
    break;
  }
}

/**
 * @brief Function for shutdown events.
 *
 * @param[in]   event       Shutdown type.
 */
static bool shutdown_handler(nrf_pwr_mgmt_evt_t event) {
  ret_code_t err_code;

  err_code = bsp_indication_set(BSP_INDICATE_IDLE);
  APP_ERROR_CHECK(err_code);

  switch (event) {
  case NRF_PWR_MGMT_EVT_PREPARE_WAKEUP:
    // Prepare wakeup buttons.
    err_code = bsp_btn_ble_sleep_mode_prepare();
    APP_ERROR_CHECK(err_code);
    break;
  default:
    break;
  }

  return true;
}

NRF_PWR_MGMT_HANDLER_REGISTER(shutdown_handler, APP_SHUTDOWN_HANDLER_PRIORITY);

/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const *p_ble_evt, void *p_context) {
  ret_code_t err_code;
  ble_gap_evt_t const *p_gap_evt = &p_ble_evt->evt.gap_evt;

  switch (p_ble_evt->header.evt_id) {
  case BLE_GAP_EVT_CONNECTED: {
    NRF_LOG_INFO("Connected.");

    // Discover peer's services.
    err_code = ble_db_discovery_start(&m_db_disc, p_ble_evt->evt.gap_evt.conn_handle);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
    APP_ERROR_CHECK(err_code);

    if (ble_conn_state_central_conn_count() < NRF_SDH_BLE_CENTRAL_LINK_COUNT) {
      scan_start();
    }
  } break;

  case BLE_GAP_EVT_DISCONNECTED: {
    NRF_LOG_INFO("Disconnected, reason 0x%x.",
        p_gap_evt->params.disconnected.reason);

    err_code = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);

    if (ble_conn_state_central_conn_count() < NRF_SDH_BLE_CENTRAL_LINK_COUNT) {
      scan_start();
    }
  } break;

  case BLE_GAP_EVT_TIMEOUT: {
    if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN) {
      NRF_LOG_INFO("Connection Request timed out.");
    }
  } break;

  case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
    // Accepting parameters requested by peer.
    err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
        &p_gap_evt->params.conn_param_update_request.conn_params);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_GAP_EVT_PHY_UPDATE_REQUEST: {
    NRF_LOG_DEBUG("PHY update request.");
    ble_gap_phys_t const phys =
        {
            .rx_phys = BLE_GAP_PHY_AUTO,
            .tx_phys = BLE_GAP_PHY_AUTO,
        };
    err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
    APP_ERROR_CHECK(err_code);
  } break;

  case BLE_GATTC_EVT_TIMEOUT:
    // Disconnect on GATT Client timeout event.
    NRF_LOG_DEBUG("GATT Client Timeout.");
    err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
        BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_GATTS_EVT_TIMEOUT:
    // Disconnect on GATT Server timeout event.
    NRF_LOG_DEBUG("GATT Server Timeout.");
    err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
        BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
    NRF_LOG_DEBUG("BLE_GAP_EVT_SEC_PARAMS_REQUEST");
    break;

  case BLE_GAP_EVT_AUTH_KEY_REQUEST:
    NRF_LOG_INFO("BLE_GAP_EVT_AUTH_KEY_REQUEST");
    break;

  case BLE_GAP_EVT_LESC_DHKEY_REQUEST:
    NRF_LOG_INFO("BLE_GAP_EVT_LESC_DHKEY_REQUEST");
    break;

  case BLE_GAP_EVT_AUTH_STATUS:
    NRF_LOG_INFO("BLE_GAP_EVT_AUTH_STATUS: status=0x%x bond=0x%x lv4: %d kdist_own:0x%x kdist_peer:0x%x",
        p_ble_evt->evt.gap_evt.params.auth_status.auth_status,
        p_ble_evt->evt.gap_evt.params.auth_status.bonded,
        p_ble_evt->evt.gap_evt.params.auth_status.sm1_levels.lv4,
        *((uint8_t *)&p_ble_evt->evt.gap_evt.params.auth_status.kdist_own),
        *((uint8_t *)&p_ble_evt->evt.gap_evt.params.auth_status.kdist_peer));
    break;

  default:
    break;
  }
}

/**@brief SoftDevice SoC event handler.
 *
 * @param[in]   evt_id      SoC event.
 * @param[in]   p_context   Context.
 */
static void soc_evt_handler(uint32_t evt_id, void *p_context) {
  switch (evt_id) {
  case NRF_EVT_FLASH_OPERATION_SUCCESS:
    /* fall through */
  case NRF_EVT_FLASH_OPERATION_ERROR:

    if (m_memory_access_in_progress) {
      m_memory_access_in_progress = false;
      scan_start();
    }
    break;

  default:
    // No implementation needed.
    break;
  }
}

/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void) {

  ble_uuid_t uuid;
  uint8_t uuid_type;

  // Add the custom service UUID to the BLE stack's table
  sd_ble_uuid_vs_add(&custom_service_uuid, &uuid_type);

  // Set up the UUID structure
  uuid.type = uuid_type;
  uuid.uuid = 0; // The least significant 16 bits of the UUID

  // Use this UUID structure when scanning for or connecting to your custom service
  ret_code_t err_code;

  err_code = nrf_sdh_enable_request();
  APP_ERROR_CHECK(err_code);

  // Configure the BLE stack using the default settings.
  // Fetch the start address of the application RAM.
  uint32_t ram_start = 0;
  err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
  APP_ERROR_CHECK(err_code);

  // Enable BLE stack.
  err_code = nrf_sdh_ble_enable(&ram_start);
  APP_ERROR_CHECK(err_code);

  // Register handlers for BLE and SoC events.
  NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
  NRF_SDH_SOC_OBSERVER(m_soc_observer, APP_SOC_OBSERVER_PRIO, soc_evt_handler, NULL);
}

/**@brief Function for the Peer Manager initialization.
 */
static void peer_manager_init(void) {
  ble_gap_sec_params_t sec_param;
  ret_code_t err_code;

  err_code = pm_init();
  APP_ERROR_CHECK(err_code);

  memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

  // Security parameters to be used for all security procedures.
  sec_param.bond = SEC_PARAM_BOND;
  sec_param.mitm = SEC_PARAM_MITM;
  sec_param.lesc = SEC_PARAM_LESC;
  sec_param.keypress = SEC_PARAM_KEYPRESS;
  sec_param.io_caps = SEC_PARAM_IO_CAPABILITIES;
  sec_param.oob = SEC_PARAM_OOB;
  sec_param.min_key_size = SEC_PARAM_MIN_KEY_SIZE;
  sec_param.max_key_size = SEC_PARAM_MAX_KEY_SIZE;
  sec_param.kdist_own.enc = 1;
  sec_param.kdist_own.id = 1;
  sec_param.kdist_peer.enc = 1;
  sec_param.kdist_peer.id = 1;

  err_code = pm_sec_params_set(&sec_param);
  APP_ERROR_CHECK(err_code);

  err_code = pm_register(pm_evt_handler);
  APP_ERROR_CHECK(err_code);
}

/** @brief Clear bonding information from persistent storage
 */
static void delete_bonds(void) {
  ret_code_t err_code;

  NRF_LOG_INFO("Erase bonds!");

  err_code = pm_peers_delete();
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for disabling the use of whitelist for scanning.
 */
static void whitelist_disable(void) {
  if (!m_whitelist_disabled) {
    NRF_LOG_INFO("Whitelist temporarily disabled.");
    m_whitelist_disabled = true;
    nrf_ble_scan_stop();
    scan_start();
  }
}

/**@brief Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
void bsp_event_handler(bsp_event_t event) {
  ret_code_t err_code;

  switch (event) {
  case BSP_EVENT_SLEEP:
    nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_SYSOFF);
    break;

  case BSP_EVENT_DISCONNECT:
    err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    if (err_code != NRF_ERROR_INVALID_STATE) {
      APP_ERROR_CHECK(err_code);
    }
    break;

  case BSP_EVENT_WHITELIST_OFF:
    whitelist_disable();
    break;

  default:
    break;
  }
}

/**@brief Heart Rate Collector Handler.
 */
static void hrs_c_evt_handler(ble_hrs_c_t *p_hrs_c, ble_hrs_c_evt_t *p_hrs_c_evt) {
  switch (p_hrs_c_evt->evt_type) {
  case BLE_HRS_C_EVT_HRM_NOTIFICATION: {
    uint8_t *data = (uint8_t *)p_hrs_c_evt->params.hrm.rr_intervals;
    uint16_t length = p_hrs_c_evt->params.hrm.rr_intervals_cnt;

    if (length > 0) {
      char message[20];
      memcpy(message, data, length);
      message[length] = '\0'; // Null-terminate the string

      NRF_LOG_INFO("Received message: %s", message);
    } else {
      NRF_LOG_WARNING("Invalid message length: %d", length);
    }
  } break;

  default:
    NRF_LOG_INFO("Unhandled HRS client event: %d", p_hrs_c_evt->evt_type);
    break;
  }
}

/**@brief Battery level Collector Handler.
 */
// static void bas_c_evt_handler(ble_bas_c_t * p_bas_c, ble_bas_c_evt_t * p_bas_c_evt)
//{
//     ret_code_t err_code;

//    switch (p_bas_c_evt->evt_type)
//    {
//        case BLE_BAS_C_EVT_DISCOVERY_COMPLETE:
//        {
//            err_code = ble_bas_c_handles_assign(p_bas_c,
//                                                p_bas_c_evt->conn_handle,
//                                                &p_bas_c_evt->params.bas_db);
//            APP_ERROR_CHECK(err_code);

//            // Battery service discovered. Enable notification of Battery Level.
//            NRF_LOG_DEBUG("Battery Service discovered. Reading battery level.");

//            err_code = ble_bas_c_bl_read(p_bas_c);
//            APP_ERROR_CHECK(err_code);

//            NRF_LOG_DEBUG("Enabling Battery Level Notification.");
//            err_code = ble_bas_c_bl_notif_enable(p_bas_c);
//            APP_ERROR_CHECK(err_code);

//        } break;

//        case BLE_BAS_C_EVT_BATT_NOTIFICATION:
//            //NRF_LOG_INFO("Battery Level received %d %%.", p_bas_c_evt->params.battery_level);
//            NRF_LOG_INFO("HELLO_CENTRAL_I_AM_PERIPHERAL_PR_007");
//            break;

//        case BLE_BAS_C_EVT_BATT_READ_RESP:
//            //NRF_LOG_INFO("Battery Level Read as %d %%.", p_bas_c_evt->params.battery_level);
//            break;

//        default:
//            break;
//    }
//}

/**
 * @brief Heart rate collector initialization.
 */
static void hrs_c_init(void) {
  ble_hrs_c_init_t hrs_c_init_obj;

  hrs_c_init_obj.evt_handler = hrs_c_evt_handler;
  hrs_c_init_obj.error_handler = service_error_handler;
  hrs_c_init_obj.p_gatt_queue = &m_ble_gatt_queue;

  ret_code_t err_code = ble_hrs_c_init(&m_hrs_c, &hrs_c_init_obj);
  APP_ERROR_CHECK(err_code);
}

/**
 * @brief Battery level collector initialization.
 */
// static void bas_c_init(void)
//{
//     ble_bas_c_init_t bas_c_init_obj;

//    bas_c_init_obj.evt_handler   = bas_c_evt_handler;
//    bas_c_init_obj.error_handler = service_error_handler;
//    bas_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

//    ret_code_t err_code = ble_bas_c_init(&m_bas_c, &bas_c_init_obj);
//    APP_ERROR_CHECK(err_code);
//}

/**
 * @brief Database discovery collector initialization.
 */
static void db_discovery_init(void) {
  ble_db_discovery_init_t db_init;

  memset(&db_init, 0, sizeof(db_init));

  db_init.evt_handler = db_disc_handler;
  db_init.p_gatt_queue = &m_ble_gatt_queue;

  ret_code_t err_code = ble_db_discovery_init(&db_init);

  APP_ERROR_CHECK(err_code);
}

/**@brief Retrieve a list of peer manager peer IDs.
 *
 * @param[inout] p_peers   The buffer where to store the list of peer IDs.
 * @param[inout] p_size    In: The size of the @p p_peers buffer.
 *                         Out: The number of peers copied in the buffer.
 */
static void peer_list_get(pm_peer_id_t *p_peers, uint32_t *p_size) {
  pm_peer_id_t peer_id;
  uint32_t peers_to_copy;

  peers_to_copy = (*p_size < BLE_GAP_WHITELIST_ADDR_MAX_COUNT) ? *p_size : BLE_GAP_WHITELIST_ADDR_MAX_COUNT;

  peer_id = pm_next_peer_id_get(PM_PEER_ID_INVALID);
  *p_size = 0;

  while ((peer_id != PM_PEER_ID_INVALID) && (peers_to_copy--)) {
    p_peers[(*p_size)++] = peer_id;
    peer_id = pm_next_peer_id_get(peer_id);
  }
}

static void whitelist_load() {
  ret_code_t ret;
  pm_peer_id_t peers[8];
  uint32_t peer_cnt;

  memset(peers, PM_PEER_ID_INVALID, sizeof(peers));
  peer_cnt = (sizeof(peers) / sizeof(pm_peer_id_t));

  // Load all peers from flash and whitelist them.
  peer_list_get(peers, &peer_cnt);

  ret = pm_whitelist_set(peers, peer_cnt);
  APP_ERROR_CHECK(ret);

  // Setup the device identies list.
  // Some SoftDevices do not support this feature.
  ret = pm_device_identities_list_set(peers, peer_cnt);
  if (ret != NRF_ERROR_NOT_SUPPORTED) {
    APP_ERROR_CHECK(ret);
  }
}

static void on_whitelist_req(void) {
  ret_code_t err_code;

  // Whitelist buffers.
  ble_gap_addr_t whitelist_addrs[8];
  ble_gap_irk_t whitelist_irks[8];

  memset(whitelist_addrs, 0x00, sizeof(whitelist_addrs));
  memset(whitelist_irks, 0x00, sizeof(whitelist_irks));

  uint32_t addr_cnt = (sizeof(whitelist_addrs) / sizeof(ble_gap_addr_t));
  uint32_t irk_cnt = (sizeof(whitelist_irks) / sizeof(ble_gap_irk_t));

  // Reload the whitelist and whitelist all peers.
  whitelist_load();

  // Get the whitelist previously set using pm_whitelist_set().
  err_code = pm_whitelist_get(whitelist_addrs, &addr_cnt,
      whitelist_irks, &irk_cnt);

  if (((addr_cnt == 0) && (irk_cnt == 0)) ||
      (m_whitelist_disabled)) {
    // Don't use whitelist.
    err_code = nrf_ble_scan_params_set(&m_scan, NULL);
    APP_ERROR_CHECK(err_code);
  }
}

/**@brief Function to start scanning.
 */
static void scan_start(void) {
  ret_code_t err_code;

  if (nrf_fstorage_is_busy(NULL)) {
    m_memory_access_in_progress = true;
    return;
  }

  NRF_LOG_INFO("Starting scan.");

  err_code = nrf_ble_scan_start(&m_scan);
  APP_ERROR_CHECK(err_code);

  err_code = bsp_indication_set(BSP_INDICATE_SCANNING);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing buttons and leds.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
 */
static void buttons_leds_init(bool *p_erase_bonds) {
  ret_code_t err_code;
  bsp_event_t startup_event;

  err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
  APP_ERROR_CHECK(err_code);

  err_code = bsp_btn_ble_init(NULL, &startup_event);
  APP_ERROR_CHECK(err_code);

  *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}

/**@brief Function for initializing the nrf log module.
 */
static void log_init(void) {
  ret_code_t err_code = NRF_LOG_INIT(NULL);
  APP_ERROR_CHECK(err_code);

  NRF_LOG_DEFAULT_BACKENDS_INIT();
}

/**@brief Function for initializing the power management module. */
static void power_management_init(void) {
  ret_code_t err_code;
  err_code = nrf_pwr_mgmt_init();
  APP_ERROR_CHECK(err_code);
}

/**@brief GATT module event handler.
 */
static void gatt_evt_handler(nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_t const *p_evt) {
  switch (p_evt->evt_id) {
  case NRF_BLE_GATT_EVT_ATT_MTU_UPDATED: {
    NRF_LOG_INFO("GATT ATT MTU on connection 0x%x changed to %d.",
        p_evt->conn_handle,
        p_evt->params.att_mtu_effective);
  } break;

  case NRF_BLE_GATT_EVT_DATA_LENGTH_UPDATED: {
    NRF_LOG_INFO("Data length for connection 0x%x updated to %d.",
        p_evt->conn_handle,
        p_evt->params.data_length);
  } break;

  default:
    break;
  }
}

static void scan_evt_handler(scan_evt_t const *p_scan_evt) {
  ret_code_t err_code;
  switch (p_scan_evt->scan_evt_id) {
  case NRF_BLE_SCAN_EVT_WHITELIST_REQUEST: {
    on_whitelist_req();
    m_whitelist_disabled = false;
  } break;

  case NRF_BLE_SCAN_EVT_CONNECTING_ERROR: {
    err_code = p_scan_evt->params.connecting_err.err_code;
    APP_ERROR_CHECK(err_code);
  } break;

  case NRF_BLE_SCAN_EVT_SCAN_TIMEOUT: {
    NRF_LOG_INFO("Scan timed out.");
    scan_start();
  } break;

  case NRF_BLE_SCAN_EVT_FILTER_MATCH:
    break;
  case NRF_BLE_SCAN_EVT_WHITELIST_ADV_REPORT:
    break;

  default:
    break;
  }
}

/**@brief Function for initializing the timer.
 */
static void timer_init(void) {
  ret_code_t err_code = app_timer_init();
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void) {
  ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initialization scanning and setting filters.
 */
static void scan_init(void) {
  ret_code_t err_code;
  nrf_ble_scan_init_t init_scan;

  ble_uuid_t uuid;
  uint8_t uuid_type;

  // Add the custom service UUID to the BLE stack's table
  sd_ble_uuid_vs_add(&custom_service_uuid, &uuid_type);

  // Set up the UUID structure
  uuid.type = uuid_type;
  uuid.uuid = 0; // The least significant 16 bits of the UUID

  memset(&init_scan, 0, sizeof(init_scan));

  init_scan.p_scan_param = &m_scan_param;
  init_scan.connect_if_match = true;
  init_scan.conn_cfg_tag = APP_BLE_CONN_CFG_TAG;

  err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
  APP_ERROR_CHECK(err_code);

  // ble_uuid_t uuid =
  //{
  //     .uuid = TARGET_UUID,
  //     .type = BLE_UUID_TYPE_BLE,
  // };

  err_code = nrf_ble_scan_filter_set(&m_scan,
      SCAN_UUID_FILTER,
      &uuid);
  APP_ERROR_CHECK(err_code);

  if (strlen(m_target_periph_name) != 0) {
    err_code = nrf_ble_scan_filter_set(&m_scan,
        SCAN_NAME_FILTER,
        m_target_periph_name);
    APP_ERROR_CHECK(err_code);
  }

  if (is_connect_per_addr) {
    err_code = nrf_ble_scan_filter_set(&m_scan,
        SCAN_ADDR_FILTER,
        m_target_periph_addr.addr);
    APP_ERROR_CHECK(err_code);
  }

  err_code = nrf_ble_scan_filters_enable(&m_scan,
      NRF_BLE_SCAN_ALL_FILTER,
      false);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling the idle state (main loop).
 *
 * @details Handle any pending log operation(s), then sleep until the next event occurs.
 */
static void idle_state_handle(void) {
  ret_code_t err_code;

  err_code = nrf_ble_lesc_request_handler();
  APP_ERROR_CHECK(err_code);

  NRF_LOG_FLUSH();
  nrf_pwr_mgmt_run();
}

/**@brief Function for starting a scan, or instead trigger it from peer manager (after
 *        deleting bonds).
 *
 * @param[in] p_erase_bonds Pointer to a bool to determine if bonds will be deleted before scanning.
 */
void scanning_start(bool *p_erase_bonds) {
  // Start scanning for peripherals and initiate connection
  // with devices that advertise GATT Service UUID.
  if (*p_erase_bonds == true) {
    // Scan is started by the PM_EVT_PEERS_DELETE_SUCCEEDED event.
    delete_bonds();
  } else {
    scan_start();
  }
}

int main(void) {
  bool erase_bonds;

  // Initialize.
  log_init();
  timer_init();
  power_management_init();
  buttons_leds_init(&erase_bonds);
  ble_stack_init();
  gatt_init();
  peer_manager_init();
  db_discovery_init();
  hrs_c_init();
  // bas_c_init();
  scan_init();

  // Start execution.
  NRF_LOG_INFO("Heart Rate collector example started.");
  scanning_start(&erase_bonds);

  // Enter main loop.
  for (;;) {
    idle_state_handle();
  }
}

static void hrs_c_evt_handler(ble_hrs_c_t *p_hrs_c, ble_hrs_c_evt_t *p_hrs_c_evt) {
switch (p_hrs_c_evt->evt_type) {
case BLE_HRS_C_EVT_HRM_NOTIFICATION: {
uint8_t *data = (uint8_t *)p_hrs_c_evt->params.hrm.rr_intervals;
uint16_t length = p_hrs_c_evt->params.hrm.rr_intervals_cnt;

if (length > 0) {
char message[20];
memcpy(message, data, length);
message[length] = '\0'; // Null-terminate the string

NRF_LOG_INFO("Received message: %s", message);
} else {
NRF_LOG_WARNING("Invalid message length: %d", length);
}
} break;

default:
NRF_LOG_INFO("Unhandled HRS client event: %d", p_hrs_c_evt->evt_type);
break;
}
}

Parents
  • //----------------------central code----------------------------------------------------------
    /**
     * Copyright (c) 2016 - 2021, Nordic Semiconductor ASA
     *
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without modification,
     * are permitted provided that the following conditions are met:
     *
     * 1. Redistributions of source code must retain the above copyright notice, this
     *    list of conditions and the following disclaimer.
     *
     * 2. Redistributions in binary form, except as embedded into a Nordic
     *    Semiconductor ASA integrated circuit in a product or a software update for
     *    such product, must reproduce the above copyright notice, this list of
     *    conditions and the following disclaimer in the documentation and/or other
     *    materials provided with the distribution.
     *
     * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
     *    contributors may be used to endorse or promote products derived from this
     *    software without specific prior written permission.
     *
     * 4. This software, with or without modification, must only be used with a
     *    Nordic Semiconductor ASA integrated circuit.
     *
     * 5. Any software provided in binary form under this license must not be reverse
     *    engineered, decompiled, modified and/or disassembled.
     *
     * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
     * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
     * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     *
     */
    #include <stdio.h>
    #include <stdint.h>
    #include <stdbool.h>
    #include "nordic_common.h"
    #include "app_error.h"
    #include "app_uart.h"
    #include "ble_db_discovery.h"
    #include "app_timer.h"
    #include "app_util.h"
    #include "bsp_btn_ble.h"
    #include "ble.h"
    #include "ble_gap.h"
    #include "ble_hci.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_sdh_soc.h"
    #include "ble_nus_c.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_pwr_mgmt.h"
    #include "nrf_ble_scan.h"
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    
    #define APP_BLE_CONN_CFG_TAG    1                                       /**< Tag that refers to the BLE stack configuration set with @ref sd_ble_cfg_set. The default tag is @ref BLE_CONN_CFG_TAG_DEFAULT. */
    #define APP_BLE_OBSERVER_PRIO   3                                       /**< BLE observer priority of the application. There is no need to modify this value. */
    
    #define UART_TX_BUF_SIZE        256                                     /**< UART TX buffer size. */
    #define UART_RX_BUF_SIZE        256                                     /**< UART RX buffer size. */
    
    #define NUS_SERVICE_UUID_TYPE   BLE_UUID_TYPE_VENDOR_BEGIN              /**< UUID type for the Nordic UART Service (vendor specific). */
    
    #define ECHOBACK_BLE_UART_DATA  1                                       /**< Echo the UART data that is received over the Nordic UART Service (NUS) back to the sender. */
    
    
    BLE_NUS_C_DEF(m_ble_nus_c);                                             /**< BLE Nordic UART Service (NUS) client instance. */
    NRF_BLE_GATT_DEF(m_gatt);                                               /**< GATT module instance. */
    BLE_DB_DISCOVERY_DEF(m_db_disc);                                        /**< Database discovery module instance. */
    NRF_BLE_SCAN_DEF(m_scan);                                               /**< Scanning Module instance. */
    NRF_BLE_GQ_DEF(m_ble_gatt_queue,                                        /**< BLE GATT Queue instance. */
                   NRF_SDH_BLE_CENTRAL_LINK_COUNT,
                   NRF_BLE_GQ_QUEUE_SIZE);
    
    static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
    
    /**@brief NUS UUID. */
    static ble_uuid_t const m_nus_uuid =
    {
        .uuid = BLE_UUID_NUS_SERVICE,
        .type = NUS_SERVICE_UUID_TYPE
    };
    
    static char const m_target_periph_name[] = "PR_007"; 
    
    /**@brief Function for handling asserts in the SoftDevice.
     *
     * @details This function is called in case of an assert in the SoftDevice.
     *
     * @warning This handler is only an example and is not meant for the final product. You need to analyze
     *          how your product is supposed to react in case of assert.
     * @warning On assert from the SoftDevice, the system can only recover on reset.
     *
     * @param[in] line_num     Line number of the failing assert call.
     * @param[in] p_file_name  File name of the failing assert call.
     */
    void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
    {
        app_error_handler(0xDEADBEEF, line_num, p_file_name);
    }
    
    
    /**@brief Function for handling the Nordic UART Service Client errors.
     *
     * @param[in]   nrf_error   Error code containing information about what went wrong.
     */
    static void nus_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    
    /**@brief Function to start scanning. */
    static void scan_start(void)
    {
        ret_code_t ret;
    
        ret = nrf_ble_scan_start(&m_scan);
        APP_ERROR_CHECK(ret);
    
        ret = bsp_indication_set(BSP_INDICATE_SCANNING);
        APP_ERROR_CHECK(ret);
    }
    
    
    /**@brief Function for handling Scanning Module events.
     */
    static void scan_evt_handler(scan_evt_t const * p_scan_evt)
    {
        ret_code_t err_code;
    
        switch(p_scan_evt->scan_evt_id)
        {
             case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
             {
                  err_code = p_scan_evt->params.connecting_err.err_code;
                  APP_ERROR_CHECK(err_code);
             } break;
    
             case NRF_BLE_SCAN_EVT_CONNECTED:
             {
                  ble_gap_evt_connected_t const * p_connected =
                                   p_scan_evt->params.connected.p_connected;
                 // Scan is automatically stopped by the connection.
                 NRF_LOG_INFO("Connecting to target %02x%02x%02x%02x%02x%02x",
                          p_connected->peer_addr.addr[0],
                          p_connected->peer_addr.addr[1],
                          p_connected->peer_addr.addr[2],
                          p_connected->peer_addr.addr[3],
                          p_connected->peer_addr.addr[4],
                          p_connected->peer_addr.addr[5]
                          );
             } break;
    
             case NRF_BLE_SCAN_EVT_SCAN_TIMEOUT:
             {
                 NRF_LOG_INFO("Scan timed out.");
                 scan_start();
             } break;
    
             default:
                 break;
        }
    }
    
    
    /**@brief Function for initializing the scanning and setting the filters.
     */
    static void scan_init(void)
    {
        ret_code_t          err_code;
        nrf_ble_scan_init_t init_scan;
    
        memset(&init_scan, 0, sizeof(init_scan));
    
        init_scan.connect_if_match = true;
        init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;
    
        err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_UUID_FILTER, &m_nus_uuid);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_UUID_FILTER, false);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling database discovery events.
     *
     * @details This function is a callback function to handle events from the database discovery module.
     *          Depending on the UUIDs that are discovered, this function forwards the events
     *          to their respective services.
     *
     * @param[in] p_event  Pointer to the database discovery event.
     */
    static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
    {
        ble_nus_c_on_db_disc_evt(&m_ble_nus_c, p_evt);
    }
    
    
    /**@brief Function for handling characters received by the Nordic UART Service (NUS).
     *
     * @details This function takes a list of characters of length data_len and prints the characters out on UART.
     *          If @ref ECHOBACK_BLE_UART_DATA is set, the data is sent back to sender.
     */
    static void ble_nus_chars_received_uart_print(uint8_t * p_data, uint16_t data_len)
    {
        ret_code_t ret_val;
    
        NRF_LOG_DEBUG("Receiving data.");
        NRF_LOG_HEXDUMP_DEBUG(p_data, data_len);
    
        for (uint32_t i = 0; i < data_len; i++)
        {
            do
            {
                ret_val = app_uart_put(p_data[i]);
                if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("app_uart_put failed for index 0x%04x.", i);
                    APP_ERROR_CHECK(ret_val);
                }
            } while (ret_val == NRF_ERROR_BUSY);
        }
        if (p_data[data_len-1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }
        if (ECHOBACK_BLE_UART_DATA)
        {
            // Send data back to the peripheral.
            do
            {
                ret_val = ble_nus_c_string_send(&m_ble_nus_c, p_data, data_len);
                if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed sending NUS message. Error 0x%x. ", ret_val);
                    APP_ERROR_CHECK(ret_val);
                }
            } while (ret_val == NRF_ERROR_BUSY);
        }
    }
    
    
    /**@brief   Function for handling app_uart events.
     *
     * @details This function receives a single character from the app_uart module and appends it to
     *          a string. The string is sent over BLE when the last character received is a
     *          'new line' '\n' (hex 0x0A) or if the string reaches the maximum data length.
     */
    void uart_event_handle(app_uart_evt_t * p_event)
    {
        static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
        static uint16_t index = 0;
        uint32_t ret_val;
    
        switch (p_event->evt_type)
        {
            /**@snippet [Handling data from UART] */
            case APP_UART_DATA_READY:
                UNUSED_VARIABLE(app_uart_get(&data_array[index]));
                index++;
    
                if ((data_array[index - 1] == '\n') ||
                    (data_array[index - 1] == '\r') ||
                    (index >= (m_ble_nus_max_data_len)))
                {
                    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
                    do
                    {
                        ret_val = ble_nus_c_string_send(&m_ble_nus_c, data_array, index);
                        if ( (ret_val != NRF_ERROR_INVALID_STATE) && (ret_val != NRF_ERROR_RESOURCES) )
                        {
                            APP_ERROR_CHECK(ret_val);
                        }
                    } while (ret_val == NRF_ERROR_RESOURCES);
    
                    index = 0;
                }
                break;
    
            /**@snippet [Handling data from UART] */
            case APP_UART_COMMUNICATION_ERROR:
                NRF_LOG_ERROR("Communication error occurred while handling UART.");
                APP_ERROR_HANDLER(p_event->data.error_communication);
                break;
    
            case APP_UART_FIFO_ERROR:
                NRF_LOG_ERROR("Error occurred in FIFO module used by UART.");
                APP_ERROR_HANDLER(p_event->data.error_code);
                break;
    
            default:
                break;
        }
    }
    
    
    /**@brief Callback handling Nordic UART Service (NUS) client events.
     *
     * @details This function is called to notify the application of NUS client events.
     *
     * @param[in]   p_ble_nus_c   NUS client handle. This identifies the NUS client.
     * @param[in]   p_ble_nus_evt Pointer to the NUS client event.
     */
    
    /**@snippet [Handling events from the ble_nus_c module] */
    static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)
    {
        ret_code_t err_code;
    
        switch (p_ble_nus_evt->evt_type)
        {
            case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
                NRF_LOG_INFO("Discovery complete.");
                err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
                APP_ERROR_CHECK(err_code);
    
                err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
                APP_ERROR_CHECK(err_code);
                NRF_LOG_INFO("Connected to device with Nordic UART Service.");
                break;
    
            case BLE_NUS_C_EVT_NUS_TX_EVT:
                ble_nus_chars_received_uart_print(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
                break;
    
            case BLE_NUS_C_EVT_DISCONNECTED:
                NRF_LOG_INFO("Disconnected.");
                scan_start();
                break;
        }
    }
    /**@snippet [Handling events from the ble_nus_c module] */
    
    
    /**
     * @brief Function for handling shutdown events.
     *
     * @param[in]   event       Shutdown type.
     */
    static bool shutdown_handler(nrf_pwr_mgmt_evt_t event)
    {
        ret_code_t err_code;
    
        err_code = bsp_indication_set(BSP_INDICATE_IDLE);
        APP_ERROR_CHECK(err_code);
    
        switch (event)
        {
            case NRF_PWR_MGMT_EVT_PREPARE_WAKEUP:
                // Prepare wakeup buttons.
                err_code = bsp_btn_ble_sleep_mode_prepare();
                APP_ERROR_CHECK(err_code);
                break;
    
            default:
                break;
        }
    
        return true;
    }
    
    NRF_PWR_MGMT_HANDLER_REGISTER(shutdown_handler, APP_SHUTDOWN_HANDLER_PRIORITY);
    
    
    /**@brief Function for handling BLE events.
     *
     * @param[in]   p_ble_evt   Bluetooth stack event.
     * @param[in]   p_context   Unused.
     */
    static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
    {
        ret_code_t            err_code;
        ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;
    
        switch (p_ble_evt->header.evt_id)
        {
            case BLE_GAP_EVT_CONNECTED:
                err_code = ble_nus_c_handles_assign(&m_ble_nus_c, p_ble_evt->evt.gap_evt.conn_handle, NULL);
                APP_ERROR_CHECK(err_code);
    
                err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
                APP_ERROR_CHECK(err_code);
    
                // start discovery of services. The NUS Client waits for a discovery result
                err_code = ble_db_discovery_start(&m_db_disc, p_ble_evt->evt.gap_evt.conn_handle);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_DISCONNECTED:
    
                NRF_LOG_INFO("Disconnected. conn_handle: 0x%x, reason: 0x%x",
                             p_gap_evt->conn_handle,
                             p_gap_evt->params.disconnected.reason);
                break;
    
            case BLE_GAP_EVT_TIMEOUT:
                if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
                {
                    NRF_LOG_INFO("Connection Request timed out.");
                }
                break;
    
            case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
                // Pairing not supported.
                err_code = sd_ble_gap_sec_params_reply(p_ble_evt->evt.gap_evt.conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
                // Accepting parameters requested by peer.
                err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                                        &p_gap_evt->params.conn_param_update_request.conn_params);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
            {
                NRF_LOG_DEBUG("PHY update request.");
                ble_gap_phys_t const phys =
                {
                    .rx_phys = BLE_GAP_PHY_AUTO,
                    .tx_phys = BLE_GAP_PHY_AUTO,
                };
                err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
                APP_ERROR_CHECK(err_code);
            } break;
    
            case BLE_GATTC_EVT_TIMEOUT:
                // Disconnect on GATT Client timeout event.
                NRF_LOG_DEBUG("GATT Client Timeout.");
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTS_EVT_TIMEOUT:
                // Disconnect on GATT Server timeout event.
                NRF_LOG_DEBUG("GATT Server Timeout.");
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            default:
                break;
        }
    }
    
    
    /**@brief Function for initializing the BLE stack.
     *
     * @details Initializes the SoftDevice and the BLE event interrupt.
     */
    static void ble_stack_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_sdh_enable_request();
        APP_ERROR_CHECK(err_code);
    
        // Configure the BLE stack using the default settings.
        // Fetch the start address of the application RAM.
        uint32_t ram_start = 0;
        err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Enable BLE stack.
        err_code = nrf_sdh_ble_enable(&ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Register a handler for BLE events.
        NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    }
    
    
    /**@brief Function for handling events from the GATT library. */
    void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
    {
        if (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED)
        {
            NRF_LOG_INFO("ATT MTU exchange completed.");
    
            m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
            NRF_LOG_INFO("Ble NUS max data length set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
        }
    }
    
    
    /**@brief Function for initializing the GATT library. */
    void gatt_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_gatt_att_mtu_central_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling events from the BSP module.
     *
     * @param[in] event  Event generated by button press.
     */
    void bsp_event_handler(bsp_event_t event)
    {
        ret_code_t err_code;
    
        switch (event)
        {
            case BSP_EVENT_SLEEP:
                nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_SYSOFF);
                break;
    
            case BSP_EVENT_DISCONNECT:
                err_code = sd_ble_gap_disconnect(m_ble_nus_c.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
                break;
    
            default:
                break;
        }
    }
    
    /**@brief Function for initializing the UART. */
    static void uart_init(void)
    {
        ret_code_t err_code;
    
        app_uart_comm_params_t const comm_params =
        {
            .rx_pin_no    = RX_PIN_NUMBER,
            .tx_pin_no    = TX_PIN_NUMBER,
            .rts_pin_no   = RTS_PIN_NUMBER,
            .cts_pin_no   = CTS_PIN_NUMBER,
            .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
            .use_parity   = false,
            .baud_rate    = UART_BAUDRATE_BAUDRATE_Baud115200
        };
    
        APP_UART_FIFO_INIT(&comm_params,
                           UART_RX_BUF_SIZE,
                           UART_TX_BUF_SIZE,
                           uart_event_handle,
                           APP_IRQ_PRIORITY_LOWEST,
                           err_code);
    
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for initializing the Nordic UART Service (NUS) client. */
    static void nus_c_init(void)
    {
        ret_code_t       err_code;
        ble_nus_c_init_t init;
    
        init.evt_handler   = ble_nus_c_evt_handler;
        init.error_handler = nus_error_handler;
        init.p_gatt_queue  = &m_ble_gatt_queue;
    
        err_code = ble_nus_c_init(&m_ble_nus_c, &init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for initializing buttons and leds. */
    static void buttons_leds_init(void)
    {
        ret_code_t err_code;
        bsp_event_t startup_event;
    
        err_code = bsp_init(BSP_INIT_LEDS, bsp_event_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = bsp_btn_ble_init(NULL, &startup_event);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for initializing the timer. */
    static void timer_init(void)
    {
        ret_code_t err_code = app_timer_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for initializing the nrf log module. */
    static void log_init(void)
    {
        ret_code_t err_code = NRF_LOG_INIT(NULL);
        APP_ERROR_CHECK(err_code);
    
        NRF_LOG_DEFAULT_BACKENDS_INIT();
    }
    
    
    /**@brief Function for initializing power management.
     */
    static void power_management_init(void)
    {
        ret_code_t err_code;
        err_code = nrf_pwr_mgmt_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /** @brief Function for initializing the database discovery module. */
    static void db_discovery_init(void)
    {
        ble_db_discovery_init_t db_init;
    
        memset(&db_init, 0, sizeof(ble_db_discovery_init_t));
    
        db_init.evt_handler  = db_disc_handler;
        db_init.p_gatt_queue = &m_ble_gatt_queue;
    
        ret_code_t err_code = ble_db_discovery_init(&db_init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling the idle state (main loop).
     *
     * @details Handles any pending log operations, then sleeps until the next event occurs.
     */
    static void idle_state_handle(void)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            nrf_pwr_mgmt_run();
        }
    }
    
    
    int main(void)
    {
        // Initialize.
        log_init();
        timer_init();
        uart_init();
        buttons_leds_init();
        db_discovery_init();
        power_management_init();
        ble_stack_init();
        gatt_init();
        nus_c_init();
        scan_init();
    
        // Start execution.
        //printf("BLE UART central example started.\r\n");
        NRF_LOG_INFO("BLE UART central example started.");
        scan_start();
    
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    //-------------------------------peripheral code-------------------------------------------
    /**
     * Copyright (c) 2014 - 2021, Nordic Semiconductor ASA
     *
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without modification,
     * are permitted provided that the following conditions are met:
     *
     * 1. Redistributions of source code must retain the above copyright notice, this
     *    list of conditions and the following disclaimer.
     *
     * 2. Redistributions in binary form, except as embedded into a Nordic
     *    Semiconductor ASA integrated circuit in a product or a software update for
     *    such product, must reproduce the above copyright notice, this list of
     *    conditions and the following disclaimer in the documentation and/or other
     *    materials provided with the distribution.
     *
     * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
     *    contributors may be used to endorse or promote products derived from this
     *    software without specific prior written permission.
     *
     * 4. This software, with or without modification, must only be used with a
     *    Nordic Semiconductor ASA integrated circuit.
     *
     * 5. Any software provided in binary form under this license must not be reverse
     *    engineered, decompiled, modified and/or disassembled.
     *
     * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
     * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
     * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     *
     */
    /** @file
     *
     * @defgroup ble_sdk_uart_over_ble_main main.c
     * @{
     * @ingroup  ble_sdk_app_nus_eval
     * @brief    UART over BLE application main file.
     *
     * This file contains the source code for a sample application that uses the Nordic UART service.
     * This application uses the @ref srvlib_conn_params module.
     */
    
    
    #include <stdint.h>
    #include <string.h>
    #include "nordic_common.h"
    #include "nrf.h"
    #include "ble_hci.h"
    #include "ble_advdata.h"
    #include "ble_advertising.h"
    #include "ble_conn_params.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_soc.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_ble_qwr.h"
    #include "app_timer.h"
    #include "ble_nus.h"
    #include "app_uart.h"
    #include "app_util_platform.h"
    #include "bsp_btn_ble.h"
    #include "nrf_pwr_mgmt.h"
    
    #if defined (UART_PRESENT)
    #include "nrf_uart.h"
    #endif
    #if defined (UARTE_PRESENT)
    #include "nrf_uarte.h"
    #endif
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    #define APP_BLE_CONN_CFG_TAG            1                                           /**< A tag identifying the SoftDevice BLE configuration. */
    
    #define DEVICE_NAME                     "PR_007"                               /**< Name of device. Will be included in the advertising data. */
    #define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**< UUID type for the Nordic UART Service (vendor specific). */
    
    #define APP_BLE_OBSERVER_PRIO           3                                           /**< Application's BLE observer priority. You shouldn't need to modify this value. */
    
    #define APP_ADV_INTERVAL                64                                          /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */
    
    #define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */
    
    #define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
    #define MAX_CONN_INTERVAL               MSEC_TO_UNITS(75, UNIT_1_25_MS)             /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
    #define SLAVE_LATENCY                   0                                           /**< Slave latency. */
    #define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
    #define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                       /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
    #define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                      /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
    #define MAX_CONN_PARAMS_UPDATE_COUNT    3                                           /**< Number of attempts before giving up the connection parameter negotiation. */
    
    #define DEAD_BEEF                       0xDEADBEEF                                  /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */
    
    #define UART_TX_BUF_SIZE                256                                         /**< UART TX buffer size. */
    #define UART_RX_BUF_SIZE                256                                         /**< UART RX buffer size. */
    
    
    BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                                   /**< BLE NUS service instance. */
    NRF_BLE_GATT_DEF(m_gatt);                                                           /**< GATT module instance. */
    NRF_BLE_QWR_DEF(m_qwr);                                                             /**< Context for the Queued Write module.*/
    BLE_ADVERTISING_DEF(m_advertising);                                                 /**< Advertising module instance. */
    
    static uint16_t   m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
    static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;            /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
    static ble_uuid_t m_adv_uuids[]          =                                          /**< Universally unique service identifier. */
    {
        {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
    };
    
    
    /**@brief Function for assert macro callback.
     *
     * @details This function will be called in case of an assert in the SoftDevice.
     *
     * @warning This handler is an example only and does not fit a final product. You need to analyse
     *          how your product is supposed to react in case of Assert.
     * @warning On assert from the SoftDevice, the system can only recover on reset.
     *
     * @param[in] line_num    Line number of the failing ASSERT call.
     * @param[in] p_file_name File name of the failing ASSERT call.
     */
    void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
    {
        app_error_handler(DEAD_BEEF, line_num, p_file_name);
    }
    
    /**@brief Function for initializing the timer module.
     */
    static void timers_init(void)
    {
        ret_code_t err_code = app_timer_init();
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for the GAP initialization.
     *
     * @details This function will set up all the necessary GAP (Generic Access Profile) parameters of
     *          the device. It also sets the permissions and appearance.
     */
    static void gap_params_init(void)
    {
        uint32_t                err_code;
        ble_gap_conn_params_t   gap_conn_params;
        ble_gap_conn_sec_mode_t sec_mode;
    
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);
    
        err_code = sd_ble_gap_device_name_set(&sec_mode,
                                              (const uint8_t *) DEVICE_NAME,
                                              strlen(DEVICE_NAME));
        APP_ERROR_CHECK(err_code);
    
        memset(&gap_conn_params, 0, sizeof(gap_conn_params));
    
        gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
        gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
        gap_conn_params.slave_latency     = SLAVE_LATENCY;
        gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;
    
        err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling Queued Write Module errors.
     *
     * @details A pointer to this function will be passed to each service which may need to inform the
     *          application about an error.
     *
     * @param[in]   nrf_error   Error code containing information about what went wrong.
     */
    static void nrf_qwr_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    
    /**@brief Function for handling the data from the Nordic UART Service.
     *
     * @details This function will process the data received from the Nordic UART BLE Service and send
     *          it to the UART module.
     *
     * @param[in] p_evt       Nordic UART Service event.
     */
    /**@snippet [Handling the data received over BLE] */
    static void nus_data_handler(ble_nus_evt_t * p_evt)
    {
    
        if (p_evt->type == BLE_NUS_EVT_RX_DATA)
        {
            uint32_t err_code;
    
            NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
            NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
    
            for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
            {
                do
                {
                    err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
                    if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                    {
                        NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                        APP_ERROR_CHECK(err_code);
                    }
                } while (err_code == NRF_ERROR_BUSY);
            }
            if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
            {
                while (app_uart_put('\n') == NRF_ERROR_BUSY);
            }
        }
    
    }
    /**@snippet [Handling the data received over BLE] */
    
    
    /**@brief Function for initializing services that will be used by the application.
     */
    static void services_init(void)
    {
        uint32_t           err_code;
        ble_nus_init_t     nus_init;
        nrf_ble_qwr_init_t qwr_init = {0};
    
        // Initialize Queued Write Module.
        qwr_init.error_handler = nrf_qwr_error_handler;
    
        err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
        APP_ERROR_CHECK(err_code);
    
        // Initialize NUS.
        memset(&nus_init, 0, sizeof(nus_init));
    
        nus_init.data_handler = nus_data_handler;
    
        err_code = ble_nus_init(&m_nus, &nus_init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling an event from the Connection Parameters Module.
     *
     * @details This function will be called for all events in the Connection Parameters Module
     *          which are passed to the application.
     *
     * @note All this function does is to disconnect. This could have been done by simply setting
     *       the disconnect_on_fail config parameter, but instead we use the event handler
     *       mechanism to demonstrate its use.
     *
     * @param[in] p_evt  Event received from the Connection Parameters Module.
     */
    static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
    {
        uint32_t err_code;
    
        if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
        {
            err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
            APP_ERROR_CHECK(err_code);
        }
    }
    
    
    /**@brief Function for handling errors from the Connection Parameters module.
     *
     * @param[in] nrf_error  Error code containing information about what went wrong.
     */
    static void conn_params_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    
    /**@brief Function for initializing the Connection Parameters module.
     */
    static void conn_params_init(void)
    {
        uint32_t               err_code;
        ble_conn_params_init_t cp_init;
    
        memset(&cp_init, 0, sizeof(cp_init));
    
        cp_init.p_conn_params                  = NULL;
        cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
        cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
        cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
        cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
        cp_init.disconnect_on_fail             = false;
        cp_init.evt_handler                    = on_conn_params_evt;
        cp_init.error_handler                  = conn_params_error_handler;
    
        err_code = ble_conn_params_init(&cp_init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for putting the chip into sleep mode.
     *
     * @note This function will not return.
     */
    static void sleep_mode_enter(void)
    {
        uint32_t err_code = bsp_indication_set(BSP_INDICATE_IDLE);
        APP_ERROR_CHECK(err_code);
    
        // Prepare wakeup buttons.
        err_code = bsp_btn_ble_sleep_mode_prepare();
        APP_ERROR_CHECK(err_code);
    
        // Go to system-off mode (this function will not return; wakeup will cause a reset).
        err_code = sd_power_system_off();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling advertising events.
     *
     * @details This function will be called for advertising events which are passed to the application.
     *
     * @param[in] ble_adv_evt  Advertising event.
     */
    static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
    {
        uint32_t err_code;
    
        switch (ble_adv_evt)
        {
            case BLE_ADV_EVT_FAST:
                err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
                APP_ERROR_CHECK(err_code);
                break;
            case BLE_ADV_EVT_IDLE:
                sleep_mode_enter();
                break;
            default:
                break;
        }
    }
    
    
    /**@brief Function for handling BLE events.
     *
     * @param[in]   p_ble_evt   Bluetooth stack event.
     * @param[in]   p_context   Unused.
     */
    static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
    {
        uint32_t err_code;
    
        switch (p_ble_evt->header.evt_id)
        {
            case BLE_GAP_EVT_CONNECTED:
                NRF_LOG_INFO("Connected");
                err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
                APP_ERROR_CHECK(err_code);
                m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
                err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_DISCONNECTED:
                NRF_LOG_INFO("Disconnected");
                // LED indication will be changed when advertising starts.
                m_conn_handle = BLE_CONN_HANDLE_INVALID;
                break;
    
            case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
            {
                NRF_LOG_DEBUG("PHY update request.");
                ble_gap_phys_t const phys =
                {
                    .rx_phys = BLE_GAP_PHY_AUTO,
                    .tx_phys = BLE_GAP_PHY_AUTO,
                };
                err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
                APP_ERROR_CHECK(err_code);
            } break;
    
            case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
                // Pairing not supported
                err_code = sd_ble_gap_sec_params_reply(m_conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTS_EVT_SYS_ATTR_MISSING:
                // No system attributes have been stored.
                err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTC_EVT_TIMEOUT:
                // Disconnect on GATT Client timeout event.
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTS_EVT_TIMEOUT:
                // Disconnect on GATT Server timeout event.
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            default:
                // No implementation needed.
                break;
        }
    }
    
    
    /**@brief Function for the SoftDevice initialization.
     *
     * @details This function initializes the SoftDevice and the BLE event interrupt.
     */
    static void ble_stack_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_sdh_enable_request();
        APP_ERROR_CHECK(err_code);
    
        // Configure the BLE stack using the default settings.
        // Fetch the start address of the application RAM.
        uint32_t ram_start = 0;
        err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Enable BLE stack.
        err_code = nrf_sdh_ble_enable(&ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Register a handler for BLE events.
        NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    }
    
    
    /**@brief Function for handling events from the GATT library. */
    void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
    {
        if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
        {
            m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
            NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
        }
        NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                      p_gatt->att_mtu_desired_central,
                      p_gatt->att_mtu_desired_periph);
    }
    
    
    /**@brief Function for initializing the GATT library. */
    void gatt_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling events from the BSP module.
     *
     * @param[in]   event   Event generated by button press.
     */
    void bsp_event_handler(bsp_event_t event)
    {
        uint32_t err_code;
        switch (event)
        {
            case BSP_EVENT_SLEEP:
                sleep_mode_enter();
                break;
    
            case BSP_EVENT_DISCONNECT:
                err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
                break;
    
            case BSP_EVENT_WHITELIST_OFF:
                if (m_conn_handle == BLE_CONN_HANDLE_INVALID)
                {
                    err_code = ble_advertising_restart_without_whitelist(&m_advertising);
                    if (err_code != NRF_ERROR_INVALID_STATE)
                    {
                        APP_ERROR_CHECK(err_code);
                    }
                }
                break;
    
            default:
                break;
        }
    }
    
    
    /**@brief   Function for handling app_uart events.
     *
     * @details This function will receive a single character from the app_uart module and append it to
     *          a string. The string will be be sent over BLE when the last character received was a
     *          'new line' '\n' (hex 0x0A) or if the string has reached the maximum data length.
     */
    /**@snippet [Handling the data received over UART] */
    void uart_event_handle(app_uart_evt_t * p_event)
    {
        static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
        static uint8_t index = 0;
        uint32_t       err_code;
    
        switch (p_event->evt_type)
        {
            case APP_UART_DATA_READY:
                UNUSED_VARIABLE(app_uart_get(&data_array[index]));
                index++;
    
                if ((data_array[index - 1] == '\n') ||
                    (data_array[index - 1] == '\r') ||
                    (index >= m_ble_nus_max_data_len))
                {
                    if (index > 1)
                    {
                        NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                        NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
                        do
                        {
                            uint16_t length = (uint16_t)index;
                            err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                            if ((err_code != NRF_ERROR_INVALID_STATE) &&
                                (err_code != NRF_ERROR_RESOURCES) &&
                                (err_code != NRF_ERROR_NOT_FOUND))
                            {
                                APP_ERROR_CHECK(err_code);
                            }
                        } while (err_code == NRF_ERROR_RESOURCES);
                    }
    
                    index = 0;
                }
                break;
    
            case APP_UART_COMMUNICATION_ERROR:
                APP_ERROR_HANDLER(p_event->data.error_communication);
                break;
    
            case APP_UART_FIFO_ERROR:
                APP_ERROR_HANDLER(p_event->data.error_code);
                break;
    
            default:
                break;
        }
    }
    /**@snippet [Handling the data received over UART] */
    
    
    /**@brief  Function for initializing the UART module.
     */
    /**@snippet [UART Initialization] */
    static void uart_init(void)
    {
        uint32_t                     err_code;
        app_uart_comm_params_t const comm_params =
        {
            .rx_pin_no    = RX_PIN_NUMBER,
            .tx_pin_no    = TX_PIN_NUMBER,
            .rts_pin_no   = RTS_PIN_NUMBER,
            .cts_pin_no   = CTS_PIN_NUMBER,
            .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
            .use_parity   = false,
    #if defined (UART_PRESENT)
            .baud_rate    = NRF_UART_BAUDRATE_115200
    #else
            .baud_rate    = NRF_UARTE_BAUDRATE_115200
    #endif
        };
    
        APP_UART_FIFO_INIT(&comm_params,
                           UART_RX_BUF_SIZE,
                           UART_TX_BUF_SIZE,
                           uart_event_handle,
                           APP_IRQ_PRIORITY_LOWEST,
                           err_code);
        APP_ERROR_CHECK(err_code);
    }
    /**@snippet [UART Initialization] */
    
    
    /**@brief Function for initializing the Advertising functionality.
     */
    static void advertising_init(void)
    {
        uint32_t               err_code;
        ble_advertising_init_t init;
    
        memset(&init, 0, sizeof(init));
    
        init.advdata.name_type          = BLE_ADVDATA_FULL_NAME;
        init.advdata.include_appearance = false;
        init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;
    
        init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
        init.srdata.uuids_complete.p_uuids  = m_adv_uuids;
    
        init.config.ble_adv_fast_enabled  = true;
        init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
        init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;
        init.evt_handler = on_adv_evt;
    
        err_code = ble_advertising_init(&m_advertising, &init);
        APP_ERROR_CHECK(err_code);
    
        ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
    }
    
    
    /**@brief Function for initializing buttons and leds.
     *
     * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
     */
    static void buttons_leds_init(bool * p_erase_bonds)
    {
        bsp_event_t startup_event;
    
        uint32_t err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = bsp_btn_ble_init(NULL, &startup_event);
        APP_ERROR_CHECK(err_code);
    
        *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
    }
    
    
    /**@brief Function for initializing the nrf log module.
     */
    static void log_init(void)
    {
        ret_code_t err_code = NRF_LOG_INIT(NULL);
        APP_ERROR_CHECK(err_code);
    
        NRF_LOG_DEFAULT_BACKENDS_INIT();
    }
    
    
    /**@brief Function for initializing power management.
     */
    static void power_management_init(void)
    {
        ret_code_t err_code;
        err_code = nrf_pwr_mgmt_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling the idle state (main loop).
     *
     * @details If there is no pending log operation, then sleep until next the next event occurs.
     */
    static void idle_state_handle(void)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            nrf_pwr_mgmt_run();
        }
    }
    
    
    /**@brief Function for starting advertising.
     */
    static void advertising_start(void)
    {
        uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Application main function.
     */
    int main(void)
    {
        bool erase_bonds;
    
        // Initialize.
        uart_init();
        log_init();
        timers_init();
        buttons_leds_init(&erase_bonds);
        power_management_init();
        ble_stack_init();
        gap_params_init();
        gatt_init();
        services_init();
        advertising_init();
        conn_params_init();
    
        // Start execution.
        //printf("\r\nUART started.\r\n");
        NRF_LOG_INFO("Debug logging for UART over RTT started.");
        advertising_start();
    
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    
    
    /**
     * @}
     */
    

    Hi Hung Bui,
    Thanks for response.

    I try ble_app_uart and ble_app_uart_c , in that ble_app_uart is peripheral code so in that i define my peripheral name which is PR_007 but facing issue in ble_app_uart_c which is central code and in that how i define peripheral name i don't know.

    i have information about my peripheral is only it's name PR_007 which also define in ble_app_uart code.
    i don't know uuid and service uuid.

    Also when i am trying to connect my peripheral device with mobile application then it's connect with mobile and show discovering services in status and after fix interval it's disconnect and again i connect it.

    when i debug ble_app_uart_c  receives this logs;
    <info> app_timer: RTC: initialized.
    <warning> UARTE: Function: nrfx_uarte_init, error code: NRF_SUCCESS.
    <info> UARTE: Transfer rx_len: 1.
    <info> UARTE: Function: nrfx_uarte_rx, error code: NRF_SUCCESS.
    <info> UARTE: Transfer rx_len: 1.
    <info> UARTE: Function: nrfx_uarte_rx, error code: NRF_SUCCESS.
    <error> app: Communication error occurred while handling UART.
    <info> app: BLE UART central example started.
    <error> app: SOFTDEVICE: ASSERTION FAILED

    please guide me to resolve this issue.

    Note: i am use nrf52832 ic both central and peripheral side.
    use 17.1.0 sdk and 6.30 segger embedded studio.

    here i attach both peripheral and central code.   

Reply
  • //----------------------central code----------------------------------------------------------
    /**
     * Copyright (c) 2016 - 2021, Nordic Semiconductor ASA
     *
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without modification,
     * are permitted provided that the following conditions are met:
     *
     * 1. Redistributions of source code must retain the above copyright notice, this
     *    list of conditions and the following disclaimer.
     *
     * 2. Redistributions in binary form, except as embedded into a Nordic
     *    Semiconductor ASA integrated circuit in a product or a software update for
     *    such product, must reproduce the above copyright notice, this list of
     *    conditions and the following disclaimer in the documentation and/or other
     *    materials provided with the distribution.
     *
     * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
     *    contributors may be used to endorse or promote products derived from this
     *    software without specific prior written permission.
     *
     * 4. This software, with or without modification, must only be used with a
     *    Nordic Semiconductor ASA integrated circuit.
     *
     * 5. Any software provided in binary form under this license must not be reverse
     *    engineered, decompiled, modified and/or disassembled.
     *
     * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
     * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
     * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     *
     */
    #include <stdio.h>
    #include <stdint.h>
    #include <stdbool.h>
    #include "nordic_common.h"
    #include "app_error.h"
    #include "app_uart.h"
    #include "ble_db_discovery.h"
    #include "app_timer.h"
    #include "app_util.h"
    #include "bsp_btn_ble.h"
    #include "ble.h"
    #include "ble_gap.h"
    #include "ble_hci.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_sdh_soc.h"
    #include "ble_nus_c.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_pwr_mgmt.h"
    #include "nrf_ble_scan.h"
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    
    #define APP_BLE_CONN_CFG_TAG    1                                       /**< Tag that refers to the BLE stack configuration set with @ref sd_ble_cfg_set. The default tag is @ref BLE_CONN_CFG_TAG_DEFAULT. */
    #define APP_BLE_OBSERVER_PRIO   3                                       /**< BLE observer priority of the application. There is no need to modify this value. */
    
    #define UART_TX_BUF_SIZE        256                                     /**< UART TX buffer size. */
    #define UART_RX_BUF_SIZE        256                                     /**< UART RX buffer size. */
    
    #define NUS_SERVICE_UUID_TYPE   BLE_UUID_TYPE_VENDOR_BEGIN              /**< UUID type for the Nordic UART Service (vendor specific). */
    
    #define ECHOBACK_BLE_UART_DATA  1                                       /**< Echo the UART data that is received over the Nordic UART Service (NUS) back to the sender. */
    
    
    BLE_NUS_C_DEF(m_ble_nus_c);                                             /**< BLE Nordic UART Service (NUS) client instance. */
    NRF_BLE_GATT_DEF(m_gatt);                                               /**< GATT module instance. */
    BLE_DB_DISCOVERY_DEF(m_db_disc);                                        /**< Database discovery module instance. */
    NRF_BLE_SCAN_DEF(m_scan);                                               /**< Scanning Module instance. */
    NRF_BLE_GQ_DEF(m_ble_gatt_queue,                                        /**< BLE GATT Queue instance. */
                   NRF_SDH_BLE_CENTRAL_LINK_COUNT,
                   NRF_BLE_GQ_QUEUE_SIZE);
    
    static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
    
    /**@brief NUS UUID. */
    static ble_uuid_t const m_nus_uuid =
    {
        .uuid = BLE_UUID_NUS_SERVICE,
        .type = NUS_SERVICE_UUID_TYPE
    };
    
    static char const m_target_periph_name[] = "PR_007"; 
    
    /**@brief Function for handling asserts in the SoftDevice.
     *
     * @details This function is called in case of an assert in the SoftDevice.
     *
     * @warning This handler is only an example and is not meant for the final product. You need to analyze
     *          how your product is supposed to react in case of assert.
     * @warning On assert from the SoftDevice, the system can only recover on reset.
     *
     * @param[in] line_num     Line number of the failing assert call.
     * @param[in] p_file_name  File name of the failing assert call.
     */
    void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
    {
        app_error_handler(0xDEADBEEF, line_num, p_file_name);
    }
    
    
    /**@brief Function for handling the Nordic UART Service Client errors.
     *
     * @param[in]   nrf_error   Error code containing information about what went wrong.
     */
    static void nus_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    
    /**@brief Function to start scanning. */
    static void scan_start(void)
    {
        ret_code_t ret;
    
        ret = nrf_ble_scan_start(&m_scan);
        APP_ERROR_CHECK(ret);
    
        ret = bsp_indication_set(BSP_INDICATE_SCANNING);
        APP_ERROR_CHECK(ret);
    }
    
    
    /**@brief Function for handling Scanning Module events.
     */
    static void scan_evt_handler(scan_evt_t const * p_scan_evt)
    {
        ret_code_t err_code;
    
        switch(p_scan_evt->scan_evt_id)
        {
             case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
             {
                  err_code = p_scan_evt->params.connecting_err.err_code;
                  APP_ERROR_CHECK(err_code);
             } break;
    
             case NRF_BLE_SCAN_EVT_CONNECTED:
             {
                  ble_gap_evt_connected_t const * p_connected =
                                   p_scan_evt->params.connected.p_connected;
                 // Scan is automatically stopped by the connection.
                 NRF_LOG_INFO("Connecting to target %02x%02x%02x%02x%02x%02x",
                          p_connected->peer_addr.addr[0],
                          p_connected->peer_addr.addr[1],
                          p_connected->peer_addr.addr[2],
                          p_connected->peer_addr.addr[3],
                          p_connected->peer_addr.addr[4],
                          p_connected->peer_addr.addr[5]
                          );
             } break;
    
             case NRF_BLE_SCAN_EVT_SCAN_TIMEOUT:
             {
                 NRF_LOG_INFO("Scan timed out.");
                 scan_start();
             } break;
    
             default:
                 break;
        }
    }
    
    
    /**@brief Function for initializing the scanning and setting the filters.
     */
    static void scan_init(void)
    {
        ret_code_t          err_code;
        nrf_ble_scan_init_t init_scan;
    
        memset(&init_scan, 0, sizeof(init_scan));
    
        init_scan.connect_if_match = true;
        init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;
    
        err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_UUID_FILTER, &m_nus_uuid);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_UUID_FILTER, false);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling database discovery events.
     *
     * @details This function is a callback function to handle events from the database discovery module.
     *          Depending on the UUIDs that are discovered, this function forwards the events
     *          to their respective services.
     *
     * @param[in] p_event  Pointer to the database discovery event.
     */
    static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
    {
        ble_nus_c_on_db_disc_evt(&m_ble_nus_c, p_evt);
    }
    
    
    /**@brief Function for handling characters received by the Nordic UART Service (NUS).
     *
     * @details This function takes a list of characters of length data_len and prints the characters out on UART.
     *          If @ref ECHOBACK_BLE_UART_DATA is set, the data is sent back to sender.
     */
    static void ble_nus_chars_received_uart_print(uint8_t * p_data, uint16_t data_len)
    {
        ret_code_t ret_val;
    
        NRF_LOG_DEBUG("Receiving data.");
        NRF_LOG_HEXDUMP_DEBUG(p_data, data_len);
    
        for (uint32_t i = 0; i < data_len; i++)
        {
            do
            {
                ret_val = app_uart_put(p_data[i]);
                if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("app_uart_put failed for index 0x%04x.", i);
                    APP_ERROR_CHECK(ret_val);
                }
            } while (ret_val == NRF_ERROR_BUSY);
        }
        if (p_data[data_len-1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }
        if (ECHOBACK_BLE_UART_DATA)
        {
            // Send data back to the peripheral.
            do
            {
                ret_val = ble_nus_c_string_send(&m_ble_nus_c, p_data, data_len);
                if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed sending NUS message. Error 0x%x. ", ret_val);
                    APP_ERROR_CHECK(ret_val);
                }
            } while (ret_val == NRF_ERROR_BUSY);
        }
    }
    
    
    /**@brief   Function for handling app_uart events.
     *
     * @details This function receives a single character from the app_uart module and appends it to
     *          a string. The string is sent over BLE when the last character received is a
     *          'new line' '\n' (hex 0x0A) or if the string reaches the maximum data length.
     */
    void uart_event_handle(app_uart_evt_t * p_event)
    {
        static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
        static uint16_t index = 0;
        uint32_t ret_val;
    
        switch (p_event->evt_type)
        {
            /**@snippet [Handling data from UART] */
            case APP_UART_DATA_READY:
                UNUSED_VARIABLE(app_uart_get(&data_array[index]));
                index++;
    
                if ((data_array[index - 1] == '\n') ||
                    (data_array[index - 1] == '\r') ||
                    (index >= (m_ble_nus_max_data_len)))
                {
                    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
                    do
                    {
                        ret_val = ble_nus_c_string_send(&m_ble_nus_c, data_array, index);
                        if ( (ret_val != NRF_ERROR_INVALID_STATE) && (ret_val != NRF_ERROR_RESOURCES) )
                        {
                            APP_ERROR_CHECK(ret_val);
                        }
                    } while (ret_val == NRF_ERROR_RESOURCES);
    
                    index = 0;
                }
                break;
    
            /**@snippet [Handling data from UART] */
            case APP_UART_COMMUNICATION_ERROR:
                NRF_LOG_ERROR("Communication error occurred while handling UART.");
                APP_ERROR_HANDLER(p_event->data.error_communication);
                break;
    
            case APP_UART_FIFO_ERROR:
                NRF_LOG_ERROR("Error occurred in FIFO module used by UART.");
                APP_ERROR_HANDLER(p_event->data.error_code);
                break;
    
            default:
                break;
        }
    }
    
    
    /**@brief Callback handling Nordic UART Service (NUS) client events.
     *
     * @details This function is called to notify the application of NUS client events.
     *
     * @param[in]   p_ble_nus_c   NUS client handle. This identifies the NUS client.
     * @param[in]   p_ble_nus_evt Pointer to the NUS client event.
     */
    
    /**@snippet [Handling events from the ble_nus_c module] */
    static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)
    {
        ret_code_t err_code;
    
        switch (p_ble_nus_evt->evt_type)
        {
            case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
                NRF_LOG_INFO("Discovery complete.");
                err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
                APP_ERROR_CHECK(err_code);
    
                err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
                APP_ERROR_CHECK(err_code);
                NRF_LOG_INFO("Connected to device with Nordic UART Service.");
                break;
    
            case BLE_NUS_C_EVT_NUS_TX_EVT:
                ble_nus_chars_received_uart_print(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
                break;
    
            case BLE_NUS_C_EVT_DISCONNECTED:
                NRF_LOG_INFO("Disconnected.");
                scan_start();
                break;
        }
    }
    /**@snippet [Handling events from the ble_nus_c module] */
    
    
    /**
     * @brief Function for handling shutdown events.
     *
     * @param[in]   event       Shutdown type.
     */
    static bool shutdown_handler(nrf_pwr_mgmt_evt_t event)
    {
        ret_code_t err_code;
    
        err_code = bsp_indication_set(BSP_INDICATE_IDLE);
        APP_ERROR_CHECK(err_code);
    
        switch (event)
        {
            case NRF_PWR_MGMT_EVT_PREPARE_WAKEUP:
                // Prepare wakeup buttons.
                err_code = bsp_btn_ble_sleep_mode_prepare();
                APP_ERROR_CHECK(err_code);
                break;
    
            default:
                break;
        }
    
        return true;
    }
    
    NRF_PWR_MGMT_HANDLER_REGISTER(shutdown_handler, APP_SHUTDOWN_HANDLER_PRIORITY);
    
    
    /**@brief Function for handling BLE events.
     *
     * @param[in]   p_ble_evt   Bluetooth stack event.
     * @param[in]   p_context   Unused.
     */
    static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
    {
        ret_code_t            err_code;
        ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;
    
        switch (p_ble_evt->header.evt_id)
        {
            case BLE_GAP_EVT_CONNECTED:
                err_code = ble_nus_c_handles_assign(&m_ble_nus_c, p_ble_evt->evt.gap_evt.conn_handle, NULL);
                APP_ERROR_CHECK(err_code);
    
                err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
                APP_ERROR_CHECK(err_code);
    
                // start discovery of services. The NUS Client waits for a discovery result
                err_code = ble_db_discovery_start(&m_db_disc, p_ble_evt->evt.gap_evt.conn_handle);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_DISCONNECTED:
    
                NRF_LOG_INFO("Disconnected. conn_handle: 0x%x, reason: 0x%x",
                             p_gap_evt->conn_handle,
                             p_gap_evt->params.disconnected.reason);
                break;
    
            case BLE_GAP_EVT_TIMEOUT:
                if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
                {
                    NRF_LOG_INFO("Connection Request timed out.");
                }
                break;
    
            case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
                // Pairing not supported.
                err_code = sd_ble_gap_sec_params_reply(p_ble_evt->evt.gap_evt.conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
                // Accepting parameters requested by peer.
                err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                                        &p_gap_evt->params.conn_param_update_request.conn_params);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
            {
                NRF_LOG_DEBUG("PHY update request.");
                ble_gap_phys_t const phys =
                {
                    .rx_phys = BLE_GAP_PHY_AUTO,
                    .tx_phys = BLE_GAP_PHY_AUTO,
                };
                err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
                APP_ERROR_CHECK(err_code);
            } break;
    
            case BLE_GATTC_EVT_TIMEOUT:
                // Disconnect on GATT Client timeout event.
                NRF_LOG_DEBUG("GATT Client Timeout.");
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTS_EVT_TIMEOUT:
                // Disconnect on GATT Server timeout event.
                NRF_LOG_DEBUG("GATT Server Timeout.");
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            default:
                break;
        }
    }
    
    
    /**@brief Function for initializing the BLE stack.
     *
     * @details Initializes the SoftDevice and the BLE event interrupt.
     */
    static void ble_stack_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_sdh_enable_request();
        APP_ERROR_CHECK(err_code);
    
        // Configure the BLE stack using the default settings.
        // Fetch the start address of the application RAM.
        uint32_t ram_start = 0;
        err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Enable BLE stack.
        err_code = nrf_sdh_ble_enable(&ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Register a handler for BLE events.
        NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    }
    
    
    /**@brief Function for handling events from the GATT library. */
    void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
    {
        if (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED)
        {
            NRF_LOG_INFO("ATT MTU exchange completed.");
    
            m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
            NRF_LOG_INFO("Ble NUS max data length set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
        }
    }
    
    
    /**@brief Function for initializing the GATT library. */
    void gatt_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_gatt_att_mtu_central_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling events from the BSP module.
     *
     * @param[in] event  Event generated by button press.
     */
    void bsp_event_handler(bsp_event_t event)
    {
        ret_code_t err_code;
    
        switch (event)
        {
            case BSP_EVENT_SLEEP:
                nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_SYSOFF);
                break;
    
            case BSP_EVENT_DISCONNECT:
                err_code = sd_ble_gap_disconnect(m_ble_nus_c.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
                break;
    
            default:
                break;
        }
    }
    
    /**@brief Function for initializing the UART. */
    static void uart_init(void)
    {
        ret_code_t err_code;
    
        app_uart_comm_params_t const comm_params =
        {
            .rx_pin_no    = RX_PIN_NUMBER,
            .tx_pin_no    = TX_PIN_NUMBER,
            .rts_pin_no   = RTS_PIN_NUMBER,
            .cts_pin_no   = CTS_PIN_NUMBER,
            .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
            .use_parity   = false,
            .baud_rate    = UART_BAUDRATE_BAUDRATE_Baud115200
        };
    
        APP_UART_FIFO_INIT(&comm_params,
                           UART_RX_BUF_SIZE,
                           UART_TX_BUF_SIZE,
                           uart_event_handle,
                           APP_IRQ_PRIORITY_LOWEST,
                           err_code);
    
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for initializing the Nordic UART Service (NUS) client. */
    static void nus_c_init(void)
    {
        ret_code_t       err_code;
        ble_nus_c_init_t init;
    
        init.evt_handler   = ble_nus_c_evt_handler;
        init.error_handler = nus_error_handler;
        init.p_gatt_queue  = &m_ble_gatt_queue;
    
        err_code = ble_nus_c_init(&m_ble_nus_c, &init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for initializing buttons and leds. */
    static void buttons_leds_init(void)
    {
        ret_code_t err_code;
        bsp_event_t startup_event;
    
        err_code = bsp_init(BSP_INIT_LEDS, bsp_event_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = bsp_btn_ble_init(NULL, &startup_event);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for initializing the timer. */
    static void timer_init(void)
    {
        ret_code_t err_code = app_timer_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for initializing the nrf log module. */
    static void log_init(void)
    {
        ret_code_t err_code = NRF_LOG_INIT(NULL);
        APP_ERROR_CHECK(err_code);
    
        NRF_LOG_DEFAULT_BACKENDS_INIT();
    }
    
    
    /**@brief Function for initializing power management.
     */
    static void power_management_init(void)
    {
        ret_code_t err_code;
        err_code = nrf_pwr_mgmt_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /** @brief Function for initializing the database discovery module. */
    static void db_discovery_init(void)
    {
        ble_db_discovery_init_t db_init;
    
        memset(&db_init, 0, sizeof(ble_db_discovery_init_t));
    
        db_init.evt_handler  = db_disc_handler;
        db_init.p_gatt_queue = &m_ble_gatt_queue;
    
        ret_code_t err_code = ble_db_discovery_init(&db_init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling the idle state (main loop).
     *
     * @details Handles any pending log operations, then sleeps until the next event occurs.
     */
    static void idle_state_handle(void)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            nrf_pwr_mgmt_run();
        }
    }
    
    
    int main(void)
    {
        // Initialize.
        log_init();
        timer_init();
        uart_init();
        buttons_leds_init();
        db_discovery_init();
        power_management_init();
        ble_stack_init();
        gatt_init();
        nus_c_init();
        scan_init();
    
        // Start execution.
        //printf("BLE UART central example started.\r\n");
        NRF_LOG_INFO("BLE UART central example started.");
        scan_start();
    
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    //-------------------------------peripheral code-------------------------------------------
    /**
     * Copyright (c) 2014 - 2021, Nordic Semiconductor ASA
     *
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without modification,
     * are permitted provided that the following conditions are met:
     *
     * 1. Redistributions of source code must retain the above copyright notice, this
     *    list of conditions and the following disclaimer.
     *
     * 2. Redistributions in binary form, except as embedded into a Nordic
     *    Semiconductor ASA integrated circuit in a product or a software update for
     *    such product, must reproduce the above copyright notice, this list of
     *    conditions and the following disclaimer in the documentation and/or other
     *    materials provided with the distribution.
     *
     * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
     *    contributors may be used to endorse or promote products derived from this
     *    software without specific prior written permission.
     *
     * 4. This software, with or without modification, must only be used with a
     *    Nordic Semiconductor ASA integrated circuit.
     *
     * 5. Any software provided in binary form under this license must not be reverse
     *    engineered, decompiled, modified and/or disassembled.
     *
     * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
     * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
     * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     *
     */
    /** @file
     *
     * @defgroup ble_sdk_uart_over_ble_main main.c
     * @{
     * @ingroup  ble_sdk_app_nus_eval
     * @brief    UART over BLE application main file.
     *
     * This file contains the source code for a sample application that uses the Nordic UART service.
     * This application uses the @ref srvlib_conn_params module.
     */
    
    
    #include <stdint.h>
    #include <string.h>
    #include "nordic_common.h"
    #include "nrf.h"
    #include "ble_hci.h"
    #include "ble_advdata.h"
    #include "ble_advertising.h"
    #include "ble_conn_params.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_soc.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_ble_qwr.h"
    #include "app_timer.h"
    #include "ble_nus.h"
    #include "app_uart.h"
    #include "app_util_platform.h"
    #include "bsp_btn_ble.h"
    #include "nrf_pwr_mgmt.h"
    
    #if defined (UART_PRESENT)
    #include "nrf_uart.h"
    #endif
    #if defined (UARTE_PRESENT)
    #include "nrf_uarte.h"
    #endif
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    #define APP_BLE_CONN_CFG_TAG            1                                           /**< A tag identifying the SoftDevice BLE configuration. */
    
    #define DEVICE_NAME                     "PR_007"                               /**< Name of device. Will be included in the advertising data. */
    #define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**< UUID type for the Nordic UART Service (vendor specific). */
    
    #define APP_BLE_OBSERVER_PRIO           3                                           /**< Application's BLE observer priority. You shouldn't need to modify this value. */
    
    #define APP_ADV_INTERVAL                64                                          /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */
    
    #define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */
    
    #define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
    #define MAX_CONN_INTERVAL               MSEC_TO_UNITS(75, UNIT_1_25_MS)             /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
    #define SLAVE_LATENCY                   0                                           /**< Slave latency. */
    #define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
    #define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                       /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
    #define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                      /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
    #define MAX_CONN_PARAMS_UPDATE_COUNT    3                                           /**< Number of attempts before giving up the connection parameter negotiation. */
    
    #define DEAD_BEEF                       0xDEADBEEF                                  /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */
    
    #define UART_TX_BUF_SIZE                256                                         /**< UART TX buffer size. */
    #define UART_RX_BUF_SIZE                256                                         /**< UART RX buffer size. */
    
    
    BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                                   /**< BLE NUS service instance. */
    NRF_BLE_GATT_DEF(m_gatt);                                                           /**< GATT module instance. */
    NRF_BLE_QWR_DEF(m_qwr);                                                             /**< Context for the Queued Write module.*/
    BLE_ADVERTISING_DEF(m_advertising);                                                 /**< Advertising module instance. */
    
    static uint16_t   m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
    static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;            /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
    static ble_uuid_t m_adv_uuids[]          =                                          /**< Universally unique service identifier. */
    {
        {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
    };
    
    
    /**@brief Function for assert macro callback.
     *
     * @details This function will be called in case of an assert in the SoftDevice.
     *
     * @warning This handler is an example only and does not fit a final product. You need to analyse
     *          how your product is supposed to react in case of Assert.
     * @warning On assert from the SoftDevice, the system can only recover on reset.
     *
     * @param[in] line_num    Line number of the failing ASSERT call.
     * @param[in] p_file_name File name of the failing ASSERT call.
     */
    void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
    {
        app_error_handler(DEAD_BEEF, line_num, p_file_name);
    }
    
    /**@brief Function for initializing the timer module.
     */
    static void timers_init(void)
    {
        ret_code_t err_code = app_timer_init();
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for the GAP initialization.
     *
     * @details This function will set up all the necessary GAP (Generic Access Profile) parameters of
     *          the device. It also sets the permissions and appearance.
     */
    static void gap_params_init(void)
    {
        uint32_t                err_code;
        ble_gap_conn_params_t   gap_conn_params;
        ble_gap_conn_sec_mode_t sec_mode;
    
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);
    
        err_code = sd_ble_gap_device_name_set(&sec_mode,
                                              (const uint8_t *) DEVICE_NAME,
                                              strlen(DEVICE_NAME));
        APP_ERROR_CHECK(err_code);
    
        memset(&gap_conn_params, 0, sizeof(gap_conn_params));
    
        gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
        gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
        gap_conn_params.slave_latency     = SLAVE_LATENCY;
        gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;
    
        err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling Queued Write Module errors.
     *
     * @details A pointer to this function will be passed to each service which may need to inform the
     *          application about an error.
     *
     * @param[in]   nrf_error   Error code containing information about what went wrong.
     */
    static void nrf_qwr_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    
    /**@brief Function for handling the data from the Nordic UART Service.
     *
     * @details This function will process the data received from the Nordic UART BLE Service and send
     *          it to the UART module.
     *
     * @param[in] p_evt       Nordic UART Service event.
     */
    /**@snippet [Handling the data received over BLE] */
    static void nus_data_handler(ble_nus_evt_t * p_evt)
    {
    
        if (p_evt->type == BLE_NUS_EVT_RX_DATA)
        {
            uint32_t err_code;
    
            NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
            NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
    
            for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
            {
                do
                {
                    err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
                    if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                    {
                        NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                        APP_ERROR_CHECK(err_code);
                    }
                } while (err_code == NRF_ERROR_BUSY);
            }
            if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
            {
                while (app_uart_put('\n') == NRF_ERROR_BUSY);
            }
        }
    
    }
    /**@snippet [Handling the data received over BLE] */
    
    
    /**@brief Function for initializing services that will be used by the application.
     */
    static void services_init(void)
    {
        uint32_t           err_code;
        ble_nus_init_t     nus_init;
        nrf_ble_qwr_init_t qwr_init = {0};
    
        // Initialize Queued Write Module.
        qwr_init.error_handler = nrf_qwr_error_handler;
    
        err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
        APP_ERROR_CHECK(err_code);
    
        // Initialize NUS.
        memset(&nus_init, 0, sizeof(nus_init));
    
        nus_init.data_handler = nus_data_handler;
    
        err_code = ble_nus_init(&m_nus, &nus_init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling an event from the Connection Parameters Module.
     *
     * @details This function will be called for all events in the Connection Parameters Module
     *          which are passed to the application.
     *
     * @note All this function does is to disconnect. This could have been done by simply setting
     *       the disconnect_on_fail config parameter, but instead we use the event handler
     *       mechanism to demonstrate its use.
     *
     * @param[in] p_evt  Event received from the Connection Parameters Module.
     */
    static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
    {
        uint32_t err_code;
    
        if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
        {
            err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
            APP_ERROR_CHECK(err_code);
        }
    }
    
    
    /**@brief Function for handling errors from the Connection Parameters module.
     *
     * @param[in] nrf_error  Error code containing information about what went wrong.
     */
    static void conn_params_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    
    /**@brief Function for initializing the Connection Parameters module.
     */
    static void conn_params_init(void)
    {
        uint32_t               err_code;
        ble_conn_params_init_t cp_init;
    
        memset(&cp_init, 0, sizeof(cp_init));
    
        cp_init.p_conn_params                  = NULL;
        cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
        cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
        cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
        cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
        cp_init.disconnect_on_fail             = false;
        cp_init.evt_handler                    = on_conn_params_evt;
        cp_init.error_handler                  = conn_params_error_handler;
    
        err_code = ble_conn_params_init(&cp_init);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for putting the chip into sleep mode.
     *
     * @note This function will not return.
     */
    static void sleep_mode_enter(void)
    {
        uint32_t err_code = bsp_indication_set(BSP_INDICATE_IDLE);
        APP_ERROR_CHECK(err_code);
    
        // Prepare wakeup buttons.
        err_code = bsp_btn_ble_sleep_mode_prepare();
        APP_ERROR_CHECK(err_code);
    
        // Go to system-off mode (this function will not return; wakeup will cause a reset).
        err_code = sd_power_system_off();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling advertising events.
     *
     * @details This function will be called for advertising events which are passed to the application.
     *
     * @param[in] ble_adv_evt  Advertising event.
     */
    static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
    {
        uint32_t err_code;
    
        switch (ble_adv_evt)
        {
            case BLE_ADV_EVT_FAST:
                err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
                APP_ERROR_CHECK(err_code);
                break;
            case BLE_ADV_EVT_IDLE:
                sleep_mode_enter();
                break;
            default:
                break;
        }
    }
    
    
    /**@brief Function for handling BLE events.
     *
     * @param[in]   p_ble_evt   Bluetooth stack event.
     * @param[in]   p_context   Unused.
     */
    static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
    {
        uint32_t err_code;
    
        switch (p_ble_evt->header.evt_id)
        {
            case BLE_GAP_EVT_CONNECTED:
                NRF_LOG_INFO("Connected");
                err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
                APP_ERROR_CHECK(err_code);
                m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
                err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GAP_EVT_DISCONNECTED:
                NRF_LOG_INFO("Disconnected");
                // LED indication will be changed when advertising starts.
                m_conn_handle = BLE_CONN_HANDLE_INVALID;
                break;
    
            case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
            {
                NRF_LOG_DEBUG("PHY update request.");
                ble_gap_phys_t const phys =
                {
                    .rx_phys = BLE_GAP_PHY_AUTO,
                    .tx_phys = BLE_GAP_PHY_AUTO,
                };
                err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
                APP_ERROR_CHECK(err_code);
            } break;
    
            case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
                // Pairing not supported
                err_code = sd_ble_gap_sec_params_reply(m_conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTS_EVT_SYS_ATTR_MISSING:
                // No system attributes have been stored.
                err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTC_EVT_TIMEOUT:
                // Disconnect on GATT Client timeout event.
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            case BLE_GATTS_EVT_TIMEOUT:
                // Disconnect on GATT Server timeout event.
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
                break;
    
            default:
                // No implementation needed.
                break;
        }
    }
    
    
    /**@brief Function for the SoftDevice initialization.
     *
     * @details This function initializes the SoftDevice and the BLE event interrupt.
     */
    static void ble_stack_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_sdh_enable_request();
        APP_ERROR_CHECK(err_code);
    
        // Configure the BLE stack using the default settings.
        // Fetch the start address of the application RAM.
        uint32_t ram_start = 0;
        err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Enable BLE stack.
        err_code = nrf_sdh_ble_enable(&ram_start);
        APP_ERROR_CHECK(err_code);
    
        // Register a handler for BLE events.
        NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    }
    
    
    /**@brief Function for handling events from the GATT library. */
    void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
    {
        if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
        {
            m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
            NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
        }
        NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                      p_gatt->att_mtu_desired_central,
                      p_gatt->att_mtu_desired_periph);
    }
    
    
    /**@brief Function for initializing the GATT library. */
    void gatt_init(void)
    {
        ret_code_t err_code;
    
        err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling events from the BSP module.
     *
     * @param[in]   event   Event generated by button press.
     */
    void bsp_event_handler(bsp_event_t event)
    {
        uint32_t err_code;
        switch (event)
        {
            case BSP_EVENT_SLEEP:
                sleep_mode_enter();
                break;
    
            case BSP_EVENT_DISCONNECT:
                err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
                break;
    
            case BSP_EVENT_WHITELIST_OFF:
                if (m_conn_handle == BLE_CONN_HANDLE_INVALID)
                {
                    err_code = ble_advertising_restart_without_whitelist(&m_advertising);
                    if (err_code != NRF_ERROR_INVALID_STATE)
                    {
                        APP_ERROR_CHECK(err_code);
                    }
                }
                break;
    
            default:
                break;
        }
    }
    
    
    /**@brief   Function for handling app_uart events.
     *
     * @details This function will receive a single character from the app_uart module and append it to
     *          a string. The string will be be sent over BLE when the last character received was a
     *          'new line' '\n' (hex 0x0A) or if the string has reached the maximum data length.
     */
    /**@snippet [Handling the data received over UART] */
    void uart_event_handle(app_uart_evt_t * p_event)
    {
        static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
        static uint8_t index = 0;
        uint32_t       err_code;
    
        switch (p_event->evt_type)
        {
            case APP_UART_DATA_READY:
                UNUSED_VARIABLE(app_uart_get(&data_array[index]));
                index++;
    
                if ((data_array[index - 1] == '\n') ||
                    (data_array[index - 1] == '\r') ||
                    (index >= m_ble_nus_max_data_len))
                {
                    if (index > 1)
                    {
                        NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                        NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
                        do
                        {
                            uint16_t length = (uint16_t)index;
                            err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                            if ((err_code != NRF_ERROR_INVALID_STATE) &&
                                (err_code != NRF_ERROR_RESOURCES) &&
                                (err_code != NRF_ERROR_NOT_FOUND))
                            {
                                APP_ERROR_CHECK(err_code);
                            }
                        } while (err_code == NRF_ERROR_RESOURCES);
                    }
    
                    index = 0;
                }
                break;
    
            case APP_UART_COMMUNICATION_ERROR:
                APP_ERROR_HANDLER(p_event->data.error_communication);
                break;
    
            case APP_UART_FIFO_ERROR:
                APP_ERROR_HANDLER(p_event->data.error_code);
                break;
    
            default:
                break;
        }
    }
    /**@snippet [Handling the data received over UART] */
    
    
    /**@brief  Function for initializing the UART module.
     */
    /**@snippet [UART Initialization] */
    static void uart_init(void)
    {
        uint32_t                     err_code;
        app_uart_comm_params_t const comm_params =
        {
            .rx_pin_no    = RX_PIN_NUMBER,
            .tx_pin_no    = TX_PIN_NUMBER,
            .rts_pin_no   = RTS_PIN_NUMBER,
            .cts_pin_no   = CTS_PIN_NUMBER,
            .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
            .use_parity   = false,
    #if defined (UART_PRESENT)
            .baud_rate    = NRF_UART_BAUDRATE_115200
    #else
            .baud_rate    = NRF_UARTE_BAUDRATE_115200
    #endif
        };
    
        APP_UART_FIFO_INIT(&comm_params,
                           UART_RX_BUF_SIZE,
                           UART_TX_BUF_SIZE,
                           uart_event_handle,
                           APP_IRQ_PRIORITY_LOWEST,
                           err_code);
        APP_ERROR_CHECK(err_code);
    }
    /**@snippet [UART Initialization] */
    
    
    /**@brief Function for initializing the Advertising functionality.
     */
    static void advertising_init(void)
    {
        uint32_t               err_code;
        ble_advertising_init_t init;
    
        memset(&init, 0, sizeof(init));
    
        init.advdata.name_type          = BLE_ADVDATA_FULL_NAME;
        init.advdata.include_appearance = false;
        init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;
    
        init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
        init.srdata.uuids_complete.p_uuids  = m_adv_uuids;
    
        init.config.ble_adv_fast_enabled  = true;
        init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
        init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;
        init.evt_handler = on_adv_evt;
    
        err_code = ble_advertising_init(&m_advertising, &init);
        APP_ERROR_CHECK(err_code);
    
        ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
    }
    
    
    /**@brief Function for initializing buttons and leds.
     *
     * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
     */
    static void buttons_leds_init(bool * p_erase_bonds)
    {
        bsp_event_t startup_event;
    
        uint32_t err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = bsp_btn_ble_init(NULL, &startup_event);
        APP_ERROR_CHECK(err_code);
    
        *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
    }
    
    
    /**@brief Function for initializing the nrf log module.
     */
    static void log_init(void)
    {
        ret_code_t err_code = NRF_LOG_INIT(NULL);
        APP_ERROR_CHECK(err_code);
    
        NRF_LOG_DEFAULT_BACKENDS_INIT();
    }
    
    
    /**@brief Function for initializing power management.
     */
    static void power_management_init(void)
    {
        ret_code_t err_code;
        err_code = nrf_pwr_mgmt_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling the idle state (main loop).
     *
     * @details If there is no pending log operation, then sleep until next the next event occurs.
     */
    static void idle_state_handle(void)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            nrf_pwr_mgmt_run();
        }
    }
    
    
    /**@brief Function for starting advertising.
     */
    static void advertising_start(void)
    {
        uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Application main function.
     */
    int main(void)
    {
        bool erase_bonds;
    
        // Initialize.
        uart_init();
        log_init();
        timers_init();
        buttons_leds_init(&erase_bonds);
        power_management_init();
        ble_stack_init();
        gap_params_init();
        gatt_init();
        services_init();
        advertising_init();
        conn_params_init();
    
        // Start execution.
        //printf("\r\nUART started.\r\n");
        NRF_LOG_INFO("Debug logging for UART over RTT started.");
        advertising_start();
    
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    
    
    /**
     * @}
     */
    

    Hi Hung Bui,
    Thanks for response.

    I try ble_app_uart and ble_app_uart_c , in that ble_app_uart is peripheral code so in that i define my peripheral name which is PR_007 but facing issue in ble_app_uart_c which is central code and in that how i define peripheral name i don't know.

    i have information about my peripheral is only it's name PR_007 which also define in ble_app_uart code.
    i don't know uuid and service uuid.

    Also when i am trying to connect my peripheral device with mobile application then it's connect with mobile and show discovering services in status and after fix interval it's disconnect and again i connect it.

    when i debug ble_app_uart_c  receives this logs;
    <info> app_timer: RTC: initialized.
    <warning> UARTE: Function: nrfx_uarte_init, error code: NRF_SUCCESS.
    <info> UARTE: Transfer rx_len: 1.
    <info> UARTE: Function: nrfx_uarte_rx, error code: NRF_SUCCESS.
    <info> UARTE: Transfer rx_len: 1.
    <info> UARTE: Function: nrfx_uarte_rx, error code: NRF_SUCCESS.
    <error> app: Communication error occurred while handling UART.
    <info> app: BLE UART central example started.
    <error> app: SOFTDEVICE: ASSERTION FAILED

    please guide me to resolve this issue.

    Note: i am use nrf52832 ic both central and peripheral side.
    use 17.1.0 sdk and 6.30 segger embedded studio.

    here i attach both peripheral and central code.   

Children
  • Hi Tirth
    I don't fully understand what's the problem you have. 
    My suggestion is to study the code of ble_app_uart and ble_app_uart_c  fully before you do any modification. 

    If you want to connect via name filter you should look at the ble_app_blinky_c there we scan and connect to device match with the name "Nordic_Blinky". You can test it with the ble_app_blinky as the peripheral. 

  • Thank for replay Hung Bui,
    currently i am facing issue send string from peripheral (ble_app_uart) to central (ble_app_uart_c) , the connection is establish perfectly and every 5 sec peripheral send data but it's not able send data via uart.
    here my peripheral code.

    The purpose of the task which i am currently doing is to send data via serial monitor (UART) from central to peripheral and peripheral to central - bidirectional. 

    please guide me.

    /**
     * Copyright (c) 2014 - 2020, Nordic Semiconductor ASA
     *
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without modification,
     * are permitted provided that the following conditions are met:
     *
     * 1. Redistributions of source code must retain the above copyright notice, this
     *    list of conditions and the following disclaimer.
     *
     * 2. Redistributions in binary form, except as embedded into a Nordic
     *    Semiconductor ASA integrated circuit in a product or a software update for
     *    such product, must reproduce the above copyright notice, this list of
     *    conditions and the following disclaimer in the documentation and/or other
     *    materials provided with the distribution.
     *
     * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
     *    contributors may be used to endorse or promote products derived from this
     *    software without specific prior written permission.
     *
     * 4. This software, with or without modification, must only be used with a
     *    Nordic Semiconductor ASA integrated circuit.
     *
     * 5. Any software provided in binary form under this license must not be reverse
     *    engineered, decompiled, modified and/or disassembled.
     *
     * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
     * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
     * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     *
     */
    /** @file
     *
     * @defgroup ble_sdk_uart_over_ble_main main.c
     * @{
     * @ingroup  ble_sdk_app_nus_eval
     * @brief    UART over BLE application main file.
     *
     * This file contains the source code for a sample application that uses the Nordic UART service.
     * This application uses the @ref srvlib_conn_params module.
     */
    
    #include "app_timer.h"
    #include "app_uart.h"
    #include "app_util_platform.h"
    #include "ble_advdata.h"
    #include "ble_advertising.h"
    #include "ble_conn_params.h"
    #include "ble_hci.h"
    #include "ble_nus.h"
    #include "bsp_btn_ble.h"
    #include "nordic_common.h"
    #include "nrf.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_ble_qwr.h"
    #include "nrf_pwr_mgmt.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_sdh_soc.h"
    #include <stdint.h>
    #include <string.h>
    
    #if defined(UART_PRESENT)
    #include "nrf_uart.h"
    #endif
    #if defined(UARTE_PRESENT)
    #include "nrf_uarte.h"
    #endif
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    #define APP_BLE_CONN_CFG_TAG 1 /**< A tag identifying the SoftDevice BLE configuration. */
    
    #define DEVICE_NAME "PR_007"                             /**< Name of device. Will be included in the advertising data. */
    #define NUS_SERVICE_UUID_TYPE BLE_UUID_TYPE_VENDOR_BEGIN /**< UUID type for the Nordic UART Service (vendor specific). */
    
    #define APP_BLE_OBSERVER_PRIO 3 /**< Application's BLE observer priority. You shouldn't need to modify this value. */
    
    #define APP_ADV_INTERVAL 64 /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */
    
    #define APP_ADV_DURATION 18000 /**< The advertising duration (180 seconds) in units of 10 milliseconds. */
    
    #define MIN_CONN_INTERVAL MSEC_TO_UNITS(20, UNIT_1_25_MS)    /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
    #define MAX_CONN_INTERVAL MSEC_TO_UNITS(75, UNIT_1_25_MS)    /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
    #define SLAVE_LATENCY 0                                      /**< Slave latency. */
    #define CONN_SUP_TIMEOUT MSEC_TO_UNITS(4000, UNIT_10_MS)     /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
    #define FIRST_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(5000) /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
    #define NEXT_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(30000) /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
    #define MAX_CONN_PARAMS_UPDATE_COUNT 3                       /**< Number of attempts before giving up the connection parameter negotiation. */
    
    #define DEAD_BEEF 0xDEADBEEF /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */
    
    #define UART_TX_BUF_SIZE 256 /**< UART TX buffer size. */
    #define UART_RX_BUF_SIZE 256 /**< UART RX buffer size. */
    
    BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT); /**< BLE NUS service instance. */
    NRF_BLE_GATT_DEF(m_gatt);                         /**< GATT module instance. */
    NRF_BLE_QWR_DEF(m_qwr);                           /**< Context for the Queued Write module.*/
    BLE_ADVERTISING_DEF(m_advertising);               /**< Advertising module instance. */
    
    static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID;               /**< Handle of the current connection. */
    static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
    static ble_uuid_t m_adv_uuids[] =                                      /**< Universally unique service identifier. */
        {
            {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}};
    
    /**@brief Function for assert macro callback.
     *
     * @details This function will be called in case of an assert in the SoftDevice.
     *
     * @warning This handler is an example only and does not fit a final product. You need to analyse
     *          how your product is supposed to react in case of Assert.
     * @warning On assert from the SoftDevice, the system can only recover on reset.
     *
     * @param[in] line_num    Line number of the failing ASSERT call.
     * @param[in] p_file_name File name of the failing ASSERT call.
     */
    void assert_nrf_callback(uint16_t line_num, const uint8_t *p_file_name) {
      app_error_handler(DEAD_BEEF, line_num, p_file_name);
    }
    
    /**@brief Function for initializing the timer module.
     */
    //static void timers_init(void) {
    //  ret_code_t err_code = app_timer_init();
    //  APP_ERROR_CHECK(err_code);
    //}
    
    
    APP_TIMER_DEF(m_timer_id);
    
    void send_data_via_nus(const char* message) {
        uint16_t length = strlen(message);
        ret_code_t err_code;
        err_code = ble_nus_data_send(&m_nus, (uint8_t*)message, &length, m_conn_handle);
        if ((err_code != NRF_ERROR_INVALID_STATE) && (err_code != NRF_ERROR_NOT_FOUND)) {
            APP_ERROR_CHECK(err_code);
        } else {
            NRF_LOG_ERROR("Failed to send data. Error: %d", err_code);
        }
    }
    
    static void timer_handler(void* p_context) {
        UNUSED_PARAMETER(p_context);
        send_data_via_nus("Slave_PR_007");
        printf("\r\nMessage sent:Slave_PR_007\r\n");
    }
    
    void timers_init(void) {
        ret_code_t err_code = app_timer_init();
        APP_ERROR_CHECK(err_code);
    
        err_code = app_timer_create(&m_timer_id, APP_TIMER_MODE_REPEATED, timer_handler);
        APP_ERROR_CHECK(err_code);
    }
    
    void application_timers_start(void) {
        ret_code_t err_code = app_timer_start(m_timer_id, APP_TIMER_TICKS(5000), NULL);
        APP_ERROR_CHECK(err_code);
    }
    
    
    
    /**@brief Function for the GAP initialization.
     *
     * @details This function will set up all the necessary GAP (Generic Access Profile) parameters of
     *          the device. It also sets the permissions and appearance.
     */
    static void gap_params_init(void) {
      uint32_t err_code;
      ble_gap_conn_params_t gap_conn_params;
      ble_gap_conn_sec_mode_t sec_mode;
    
      BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);
    
      err_code = sd_ble_gap_device_name_set(&sec_mode,
          (const uint8_t *)DEVICE_NAME,
          strlen(DEVICE_NAME));
      APP_ERROR_CHECK(err_code);
    
      memset(&gap_conn_params, 0, sizeof(gap_conn_params));
    
      gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
      gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
      gap_conn_params.slave_latency = SLAVE_LATENCY;
      gap_conn_params.conn_sup_timeout = CONN_SUP_TIMEOUT;
    
      err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling Queued Write Module errors.
     *
     * @details A pointer to this function will be passed to each service which may need to inform the
     *          application about an error.
     *
     * @param[in]   nrf_error   Error code containing information about what went wrong.
     */
    static void nrf_qwr_error_handler(uint32_t nrf_error) {
      APP_ERROR_HANDLER(nrf_error);
    }
    
    /**@brief Function for handling the data from the Nordic UART Service.
     *
     * @details This function will process the data received from the Nordic UART BLE Service and send
     *          it to the UART module.
     *
     * @param[in] p_evt       Nordic UART Service event.
     */
    /**@snippet [Handling the data received over BLE] */
    static void nus_data_handler(ble_nus_evt_t *p_evt) {
    
      if (p_evt->type == BLE_NUS_EVT_RX_DATA) {
        uint32_t err_code;
    
        NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
        printf("\r\nReceived data from BLE NUS. Writing data on UART.\r\n");
        NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
    
        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++) {
          do {
            err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
            if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY)) {
              NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
              printf("\r\nFailed receiving NUS message. Error 0x%x.\r\n", err_code);
              APP_ERROR_CHECK(err_code);
            }
          } while (err_code == NRF_ERROR_BUSY);
        }
        if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r') {
          while (app_uart_put('\n') == NRF_ERROR_BUSY)
            ;
        }
      }
    }
    /**@snippet [Handling the data received over BLE] */
    
    /**@brief Function for initializing services that will be used by the application.
     */
    static void services_init(void) {
      uint32_t err_code;
      ble_nus_init_t nus_init;
      nrf_ble_qwr_init_t qwr_init = {0};
    
      // Initialize Queued Write Module.
      qwr_init.error_handler = nrf_qwr_error_handler;
    
      err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
      APP_ERROR_CHECK(err_code);
    
      // Initialize NUS.
      memset(&nus_init, 0, sizeof(nus_init));
    
      nus_init.data_handler = nus_data_handler;
    
      err_code = ble_nus_init(&m_nus, &nus_init);
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling an event from the Connection Parameters Module.
     *
     * @details This function will be called for all events in the Connection Parameters Module
     *          which are passed to the application.
     *
     * @note All this function does is to disconnect. This could have been done by simply setting
     *       the disconnect_on_fail config parameter, but instead we use the event handler
     *       mechanism to demonstrate its use.
     *
     * @param[in] p_evt  Event received from the Connection Parameters Module.
     */
    static void on_conn_params_evt(ble_conn_params_evt_t *p_evt) {
      uint32_t err_code;
    
      if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED) {
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
        APP_ERROR_CHECK(err_code);
      }
    }
    
    /**@brief Function for handling errors from the Connection Parameters module.
     *
     * @param[in] nrf_error  Error code containing information about what went wrong.
     */
    static void conn_params_error_handler(uint32_t nrf_error) {
      APP_ERROR_HANDLER(nrf_error);
    }
    
    /**@brief Function for initializing the Connection Parameters module.
     */
    static void conn_params_init(void) {
      uint32_t err_code;
      ble_conn_params_init_t cp_init;
    
      memset(&cp_init, 0, sizeof(cp_init));
    
      cp_init.p_conn_params = NULL;
      cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
      cp_init.next_conn_params_update_delay = NEXT_CONN_PARAMS_UPDATE_DELAY;
      cp_init.max_conn_params_update_count = MAX_CONN_PARAMS_UPDATE_COUNT;
      cp_init.start_on_notify_cccd_handle = BLE_GATT_HANDLE_INVALID;
      cp_init.disconnect_on_fail = false;
      cp_init.evt_handler = on_conn_params_evt;
      cp_init.error_handler = conn_params_error_handler;
    
      err_code = ble_conn_params_init(&cp_init);
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for putting the chip into sleep mode.
     *
     * @note This function will not return.
     */
    static void sleep_mode_enter(void) {
      uint32_t err_code = bsp_indication_set(BSP_INDICATE_IDLE);
      APP_ERROR_CHECK(err_code);
    
      // Prepare wakeup buttons.
      err_code = bsp_btn_ble_sleep_mode_prepare();
      APP_ERROR_CHECK(err_code);
    
      // Go to system-off mode (this function will not return; wakeup will cause a reset).
      err_code = sd_power_system_off();
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling advertising events.
     *
     * @details This function will be called for advertising events which are passed to the application.
     *
     * @param[in] ble_adv_evt  Advertising event.
     */
    static void on_adv_evt(ble_adv_evt_t ble_adv_evt) {
      uint32_t err_code;
    
      switch (ble_adv_evt) {
      case BLE_ADV_EVT_FAST:
        err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
        APP_ERROR_CHECK(err_code);
        break;
      case BLE_ADV_EVT_IDLE:
        sleep_mode_enter();
        break;
      default:
        break;
      }
    }
    
    /**@brief Function for handling BLE events.
     *
     * @param[in]   p_ble_evt   Bluetooth stack event.
     * @param[in]   p_context   Unused.
     */
    static void ble_evt_handler(ble_evt_t const *p_ble_evt, void *p_context) {
      uint32_t err_code;
    
      switch (p_ble_evt->header.evt_id) {
      case BLE_GAP_EVT_CONNECTED:
        NRF_LOG_INFO("Connected");
        printf("\r\nConnected\r\n");
        err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
        APP_ERROR_CHECK(err_code);
        m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
        err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
        APP_ERROR_CHECK(err_code);
        break;
    
      case BLE_GAP_EVT_DISCONNECTED:
        NRF_LOG_INFO("Disconnected");
        printf("\r\nDisconnected\r\n");
        // LED indication will be changed when advertising starts.
        m_conn_handle = BLE_CONN_HANDLE_INVALID;
        break;
    
      case BLE_GAP_EVT_PHY_UPDATE_REQUEST: {
        NRF_LOG_DEBUG("PHY update request.");
        ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
        err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
        APP_ERROR_CHECK(err_code);
      } break;
    
      case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
        // Pairing not supported
        err_code = sd_ble_gap_sec_params_reply(m_conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
        APP_ERROR_CHECK(err_code);
        break;
    
      case BLE_GATTS_EVT_SYS_ATTR_MISSING:
        // No system attributes have been stored.
        err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
        APP_ERROR_CHECK(err_code);
        break;
    
      case BLE_GATTC_EVT_TIMEOUT:
        // Disconnect on GATT Client timeout event.
        err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
            BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
        APP_ERROR_CHECK(err_code);
        break;
    
      case BLE_GATTS_EVT_TIMEOUT:
        // Disconnect on GATT Server timeout event.
        err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
            BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
        APP_ERROR_CHECK(err_code);
        break;
    
      default:
        // No implementation needed.
        break;
      }
    }
    
    /**@brief Function for the SoftDevice initialization.
     *
     * @details This function initializes the SoftDevice and the BLE event interrupt.
     */
    static void ble_stack_init(void) {
      ret_code_t err_code;
    
      err_code = nrf_sdh_enable_request();
      APP_ERROR_CHECK(err_code);
    
      // Configure the BLE stack using the default settings.
      // Fetch the start address of the application RAM.
      uint32_t ram_start = 0;
      err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
      APP_ERROR_CHECK(err_code);
    
      // Enable BLE stack.
      err_code = nrf_sdh_ble_enable(&ram_start);
      APP_ERROR_CHECK(err_code);
    
      // Register a handler for BLE events.
      NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    }
    
    /**@brief Function for handling events from the GATT library. */
    void gatt_evt_handler(nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_t const *p_evt) {
      if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED)) {
        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
      }
      NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
          p_gatt->att_mtu_desired_central,
          p_gatt->att_mtu_desired_periph);
    }
    
    /**@brief Function for initializing the GATT library. */
    void gatt_init(void) {
      ret_code_t err_code;
    
      err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
      APP_ERROR_CHECK(err_code);
    
      err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling events from the BSP module.
     *
     * @param[in]   event   Event generated by button press.
     */
    void bsp_event_handler(bsp_event_t event) {
      uint32_t err_code;
      switch (event) {
      case BSP_EVENT_SLEEP:
        sleep_mode_enter();
        break;
    
      case BSP_EVENT_DISCONNECT:
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
        if (err_code != NRF_ERROR_INVALID_STATE) {
          APP_ERROR_CHECK(err_code);
        }
        break;
    
      case BSP_EVENT_WHITELIST_OFF:
        if (m_conn_handle == BLE_CONN_HANDLE_INVALID) {
          err_code = ble_advertising_restart_without_whitelist(&m_advertising);
          if (err_code != NRF_ERROR_INVALID_STATE) {
            APP_ERROR_CHECK(err_code);
          }
        }
        break;
    
      default:
        break;
      }
    }
    
    /**@brief   Function for handling app_uart events.
     *
     * @details This function will receive a single character from the app_uart module and append it to
     *          a string. The string will be be sent over BLE when the last character received was a
     *          'new line' '\n' (hex 0x0A) or if the string has reached the maximum data length.
     */
    /**@snippet [Handling the data received over UART] */
    
    //void send_data_via_nus(float X, float Y, ble_nus_t nus_service) {
    //  uint8_t data[8];
    //  memcpy(data, &X, sizeof(X));
    //  memcpy(data + sizeof(X), &Y, sizeof(Y));
    
    //  uint16_t length = sizeof(X) + sizeof(Y);
    //  ret_code_t err_code;
    //  err_code = ble_nus_data_send(&m_nus, data, &length, m_conn_handle);
    //  if ((err_code != NRF_ERROR_INVALID_STATE) && (err_code != NRF_ERROR_NOT_FOUND)) {
    //    APP_ERROR_CHECK(err_code);
    //  } else {
    //    NRF_LOG_ERROR("Failed to send data. Error: %d", err_code);
    //  }
    //}
    
    //int iii = 35;
    //float fff = 0.123456789;
    
    //uint8_t nus_string[50];
    //bytes_to_send = sprintf(nus_string, "int = %d, float = %f\r\n",iii,fff);
    
    //err_code = ble_nus_data_send(&m_nus, nus_string, &bytes_to_send, m_conn_handle);
    
    //if ((err_code != NRF_ERROR_INVALID_STATE) && (err_code != NRF_ERROR_NOT_FOUND))
    //{
    //    APP_ERROR_CHECK(err_code);
    //}
    
    void uart_event_handle(app_uart_evt_t *p_event) {
      static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
      static uint8_t index = 0;
      uint32_t err_code;
    
      switch (p_event->evt_type) {
      case APP_UART_DATA_READY:
        UNUSED_VARIABLE(app_uart_get(&data_array[index]));
        index++;
    
        if ((data_array[index - 1] == '\n') || (index >= m_ble_nus_max_data_len)) {
          if (index > 1) {
            float X = 1.23; // Example value, replace with your actual data
            float Y = 4.56; // Example value, replace with your actual data
            //send_data_via_nus(X, Y, m_nus);
          }
          index = 0;
        }
        break;
    
      case APP_UART_COMMUNICATION_ERROR:
        APP_ERROR_HANDLER(p_event->data.error_communication);
        break;
    
      case APP_UART_FIFO_ERROR:
        APP_ERROR_HANDLER(p_event->data.error_code);
        break;
    
      default:
        break;
      }
    }
    
    //void uart_event_handle(app_uart_evt_t *p_event) {
    //  static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
    //  static uint8_t index = 0;
    //  uint32_t err_code;
    
    //  switch (p_event->evt_type) {
    //  case APP_UART_DATA_READY:
    //    UNUSED_VARIABLE(app_uart_get(&data_array[index]));
    //    index++;
    
    //    if ((data_array[index - 1] == '\n') ||
    //        (data_array[index - 1] == '\r') ||
    //        (index >= m_ble_nus_max_data_len)) {
    //      if (index > 1) {
    //        NRF_LOG_DEBUG("Ready to send data over BLE NUS");
    //        NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
    //        do {
    //          uint16_t length = (uint16_t)index;
    //          err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
    //          if ((err_code != NRF_ERROR_INVALID_STATE) &&
    //              (err_code != NRF_ERROR_RESOURCES) &&
    //              (err_code != NRF_ERROR_NOT_FOUND)) {
    //            APP_ERROR_CHECK(err_code);
    //          }
    //        } while (err_code == NRF_ERROR_RESOURCES);
    //      }
    
    //      index = 0;
    //    }
    //    break;
    
    //  case APP_UART_COMMUNICATION_ERROR:
    //    APP_ERROR_HANDLER(p_event->data.error_communication);
    //    break;
    
    //  case APP_UART_FIFO_ERROR:
    //    APP_ERROR_HANDLER(p_event->data.error_code);
    //    break;
    
    //  default:
    //    break;
    //  }
    //}
    /**@snippet [Handling the data received over UART] */
    
    /**@brief  Function for initializing the UART module.
     */
    /**@snippet [UART Initialization] */
    static void uart_init(void) {
      uint32_t err_code;
      app_uart_comm_params_t const comm_params =
      {
        .rx_pin_no = RX_PIN_NUMBER,
        .tx_pin_no = TX_PIN_NUMBER,
        .rts_pin_no = RTS_PIN_NUMBER,
        .cts_pin_no = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity = false,
    #if defined(UART_PRESENT)
        .baud_rate = NRF_UART_BAUDRATE_115200
    #else
        .baud_rate = NRF_UARTE_BAUDRATE_115200
    #endif
      };
    
      APP_UART_FIFO_INIT(&comm_params,
          UART_RX_BUF_SIZE,
          UART_TX_BUF_SIZE,
          uart_event_handle,
          APP_IRQ_PRIORITY_LOWEST,
          err_code);
      APP_ERROR_CHECK(err_code);
    }
    /**@snippet [UART Initialization] */
    
    /**@brief Function for initializing the Advertising functionality.
     */
    static void advertising_init(void) {
      uint32_t err_code;
      ble_advertising_init_t init;
    
      memset(&init, 0, sizeof(init));
    
      init.advdata.name_type = BLE_ADVDATA_FULL_NAME;
      init.advdata.include_appearance = false;
      init.advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;
    
      init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
      init.srdata.uuids_complete.p_uuids = m_adv_uuids;
    
      init.config.ble_adv_fast_enabled = true;
      init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
      init.config.ble_adv_fast_timeout = APP_ADV_DURATION;
      init.evt_handler = on_adv_evt;
    
      err_code = ble_advertising_init(&m_advertising, &init);
      APP_ERROR_CHECK(err_code);
    
      ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
    }
    
    /**@brief Function for initializing buttons and leds.
     *
     * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
     */
    static void buttons_leds_init(bool *p_erase_bonds) {
      bsp_event_t startup_event;
    
      uint32_t err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
      APP_ERROR_CHECK(err_code);
    
      err_code = bsp_btn_ble_init(NULL, &startup_event);
      APP_ERROR_CHECK(err_code);
    
      *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
    }
    
    /**@brief Function for initializing the nrf log module.
     */
    static void log_init(void) {
      ret_code_t err_code = NRF_LOG_INIT(NULL);
      APP_ERROR_CHECK(err_code);
    
      NRF_LOG_DEFAULT_BACKENDS_INIT();
    }
    
    /**@brief Function for initializing power management.
     */
    static void power_management_init(void) {
      ret_code_t err_code;
      err_code = nrf_pwr_mgmt_init();
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling the idle state (main loop).
     *
     * @details If there is no pending log operation, then sleep until next the next event occurs.
     */
    static void idle_state_handle(void) {
      if (NRF_LOG_PROCESS() == false) {
        nrf_pwr_mgmt_run();
      }
    }
    
    /**@brief Function for starting advertising.
     */
    static void advertising_start(void) {
      uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
      APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Application main function.
     */
    int main(void) {
      bool erase_bonds;
    
      // Initialize.
      uart_init();
      log_init();
      timers_init();
      buttons_leds_init(&erase_bonds);
      power_management_init();
      ble_stack_init();
      gap_params_init();
      gatt_init();
      services_init();
      advertising_init();
      conn_params_init();
    
      // Start execution.
      printf("\r\nUART started.\r\n");
      NRF_LOG_INFO("Debug logging for UART over RTT started.");
      advertising_start();
      application_timers_start();
    
      // Enter main loop.
      for (;;) {
        idle_state_handle();
      }
    }
    
    /**
     * @}
     */
       

  • Hi , 

    Have you tried to test the sample with no modification ? 
    You need to show the code where you make the modification, only show the modification, not sending us the whole file so we need to look for it. 

  • Yes Hung Bui,
    firstly i try code without changes and i connect peripheral with mobile application and peripheral is able to receives data and able to show that data on serial monitor, but when i try to send data peripheral to mobile application via serial monitor it's not sending or mobile application not receives that string.

    after that i am with 1 central and 1 peripheral device but in this case peripheral not able to receives data as well as when it send data central not receives the data. 

    Please guide me to made bi directional communication bridge between central and peripheral device.

    Note: I am use 2 nrf52832 device, SDK version 17.0.2 and segger version is 5.42a

  • Hi, 
    You may need to press enter before you can send. Or it need to hit the maximum data length. 

    Please try to step in the code and debug. It's not a black box. You need to find the place where the data is sent from the peripheral and figure out why it's not called. 

     switch (p_event->evt_type)
        {
            case APP_UART_DATA_READY:
                UNUSED_VARIABLE(app_uart_get(&data_array[index]));
                index++;
    
                if ((data_array[index - 1] == '\n') ||
                    (data_array[index - 1] == '\r') ||
                    (index >= m_ble_nus_max_data_len))
                {
                    if (index > 1)
                    {
                        NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                        NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
                        do
                        {
                            uint16_t length = (uint16_t)index;
                            err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                            if ((err_code != NRF_ERROR_INVALID_STATE) &&
                                (err_code != NRF_ERROR_RESOURCES) &&
                                (err_code != NRF_ERROR_NOT_FOUND))
                            {
                                APP_ERROR_CHECK(err_code);
                            }
                        } while (err_code == NRF_ERROR_RESOURCES);
                    }
    
                    index = 0;
                }
                break;

Related