nrf52832 MDBT42Q Advertising issue when duration is set for 20 min....

Hello,

I am using MDBT42Q nrf52832 module, SDK 15.3.0  in Segger Studio IDE,on Win10.

I am configuring my device to advertise for 20 min, 5 min fast advertising and 15 min slow Advertising but after 10 min controller is getting stuck.

I have tried with 15 min advertising , in which 5 min is fast advertising and 10 min slow advertising at that time  I am not facing any issue.

Below is the advertising initialization function:

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      = false;
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;

#if 1
init.config.ble_adv_fast_enabled  = true;
init.config.ble_adv_fast_interval = APP_FAST_ADV_INTERVAL;
init.config.ble_adv_fast_timeout  = APP_FAST_ADV_DURATION;

init.config.ble_adv_slow_enabled  = true;
init.config.ble_adv_slow_interval = APP_SLOW_ADV_INTERVAL;
init.config.ble_adv_slow_timeout  = APP_SLOW_ADV_DURATION;
#endif

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);
}

Here are the macro value for duration:

#define APP_FAST_ADV_INTERVAL           480                                     /*< The advertising interval (in units of 0.625 ms. This value corresponds to 300 ms). /
#define APP_SLOW_ADV_INTERVAL           1600                                    /*< The advertising interval (in units of 0.625 ms. This value corresponds to 1000 ms). /
                                        
#define APP_FAST_ADV_DURATION           30000                                   /*< The advertising duration (300 seconds) in units of 10 milliseconds. /
#define APP_SLOW_ADV_DURATION           90000                                   /*< The advertising duration (900 seconds) in units of 10 milliseconds. /

Kindly help me out in figuring the issue.

Regards, 

Urvisha 

  • Can you see the same for instance if you use \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_hrs and only update intervals?

  • Can you see the same for instance if you use \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_hrs and only update intervals?

    Hello Kenneth, 

    Thanks for your reply, I have already tested the \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_template in that also I am facing the same issue. I have tested the example on nrf52832 DK board.

    If I am configuring the fast advertising and slow advertising interval both as 10 mins , that time its advertising for 20 min properly. 

  • I have been running the \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_hrs for a while with your settings, seems to work. I will let it run for a while more. Maybe you can give it one more go:

    main.c
    /**
     * Copyright (c) 2014 - 2019, 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.
     */
    
    #include <stdint.h>
    #include <string.h>
    #include "nordic_common.h"
    #include "nrf.h"
    #include "nrf_sdm.h"
    #include "app_error.h"
    #include "ble.h"
    #include "ble_err.h"
    #include "ble_hci.h"
    #include "ble_srv_common.h"
    #include "ble_advdata.h"
    #include "ble_advertising.h"
    #include "ble_bas.h"
    #include "ble_hrs.h"
    #include "ble_dis.h"
    #include "ble_conn_params.h"
    #include "sensorsim.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_sdh_soc.h"
    #include "app_timer.h"
    #include "bsp_btn_ble.h"
    #include "peer_manager.h"
    #include "peer_manager_handler.h"
    #include "fds.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_ble_lesc.h"
    #include "nrf_ble_qwr.h"
    #include "ble_conn_state.h"
    #include "nrf_pwr_mgmt.h"
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    
    #define DEVICE_NAME                         "Nordic_HRM"                            /**< 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_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)
    {
        static uint32_t cnt = 0;
        ret_code_t      err_code;
        uint16_t        heart_rate;
    
        UNUSED_PARAMETER(p_context);
    
        heart_rate = (uint16_t)sensorsim_measure(&m_heart_rate_sim_state, &m_heart_rate_sim_cfg);
    
        cnt++;
        err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, heart_rate);
        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);
        }
    
        // Disable RR Interval recording every third heart rate measurement.
        // NOTE: An application will normally not do this. It is done here just for testing generation
        // of messages without RR Interval measurements.
        m_rr_interval_enabled = ((cnt % 3) != 0);
    }
    
    
    /**@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 = true;
        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.");
                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, 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)
                {
                    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);
    }
    
    #define APP_FAST_ADV_INTERVAL           480                                     /*< The advertising interval (in units of 0.625 ms. This value corresponds to 300 ms). */
    #define APP_SLOW_ADV_INTERVAL           1600                                    /*< The advertising interval (in units of 0.625 ms. This value corresponds to 1000 ms). */
                                            
    #define APP_FAST_ADV_DURATION           30000                                   /*< The advertising duration (300 seconds) in units of 10 milliseconds. */
    #define APP_SLOW_ADV_DURATION           90000                                   /*< The advertising duration (900 seconds) in units of 10 milliseconds. */
    
    /**@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      = false;
        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_FAST_ADV_INTERVAL;
    		init.config.ble_adv_fast_timeout  	= APP_FAST_ADV_DURATION;
    
    		init.config.ble_adv_slow_enabled  	= true;
    		init.config.ble_adv_slow_interval 	= APP_SLOW_ADV_INTERVAL;
    		init.config.ble_adv_slow_timeout  	= APP_SLOW_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();
        }
    }