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HID Keyboard Example Modification

Hello,

I've been playing around with the nrf52 DK (sdk 16.0.0, s132). I'm trying to add volume up/volume down functionality to the example. I found this source code from an earlier SDK and I've been trying to follow the changes in SDK 16.0.0  https://github.com/Rallare/nrf51_ble_app_hids_kbd_consumercontrol/blob/master/main.c

So far I've added everything highlighted

1) The following changes were added to allow for repairing. This works fine.

2) The following code was added to allow button 3 and button 4 functionality on the nrf52832 board. This works fine (I can see the printf statements in the debug console when I press the buttons).

  

3) Now here it gets tricky. I'm trying to utilize the ble_hids_inp_rep_send() function to send data. So I've added the following

 - enum to organize commands

 - helper function 

 - the following constants

 - and the following lines inside the hids_init() function:

 

Clearly I'm missing something or I'm doing something wrong since when I run it and click on button 1, it works fine, but when I click on either button 3 or 4 the following error occours (here's the stack trace):


 

NOTE: consumer_control_send() is the function that I added.


 

If you could help me out to figure out what's wrong or point me in the right direction I would be very much obliged! 

Also I have attached main.c in case you would like to run it Slight smile

 

Best,

Ricky

PS: Sorry for the lengthy post with lots of pictures. If you have a better way to communicate technical details please let me know! 

/**
 * Copyright (c) 2012 - 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.
 *
 */
/** @file
 *
 * @defgroup ble_sdk_app_hids_keyboard_main main.c
 * @{
 * @ingroup ble_sdk_app_hids_keyboard
 * @brief HID Keyboard Sample Application main file.
 *
 * This file contains is the source code for a sample application using the HID, Battery and Device
 * Information Services for implementing a simple keyboard functionality.
 * Pressing Button 0 will send text 'hello' to the connected peer. On receiving output report,
 * it toggles the state of LED 2 on the mother board based on whether or not Caps Lock is on.
 * This application uses the @ref app_scheduler.
 *
 * Also it would accept pairing requests from any peer device.
 */

#include "app_error.h"
#include "app_scheduler.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_hids.h"
#include "ble_srv_common.h"
#include "bsp_btn_ble.h"
#include "fds.h"
#include "nordic_common.h"
#include "nrf.h"
#include "nrf_assert.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 "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 SHIFT_BUTTON_ID 1 /**< Button used as 'SHIFT' Key. */

#define VOLDOWN_BUTTON BSP_BUTTON_2
#define VOLUP_BUTTON BSP_BUTTON_3

#define DEVICE_NAME "Nordic_Keyboard"           /**< Name of device. Will be included in the advertising data. */
#define MANUFACTURER_NAME "NordicSemiconductor" /**< Manufacturer. Will be passed to Device Information Service. */

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

#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 battery level. */
#define BATTERY_LEVEL_INCREMENT 1                         /**< Increment between each simulated battery level measurement. */

#define PNP_ID_VENDOR_ID_SOURCE 0x02  /**< Vendor ID Source. */
#define PNP_ID_VENDOR_ID 0x1915       /**< Vendor ID. */
#define PNP_ID_PRODUCT_ID 0xEEEE      /**< Product ID. */
#define PNP_ID_PRODUCT_VERSION 0x0001 /**< Product Version. */

#define APP_ADV_FAST_INTERVAL 0x0028 /**< Fast advertising interval (in units of 0.625 ms. This value corresponds to 25 ms.). */
#define APP_ADV_SLOW_INTERVAL 0x0C80 /**< Slow advertising interval (in units of 0.625 ms. This value corrsponds to 2 seconds). */

#define APP_ADV_FAST_DURATION 3000  /**< The advertising duration of fast advertising in units of 10 milliseconds. */
#define APP_ADV_SLOW_DURATION 18000 /**< The advertising duration of slow advertising in units of 10 milliseconds. */

/*lint -emacro(524, MIN_CONN_INTERVAL) // Loss of precision */
#define MIN_CONN_INTERVAL MSEC_TO_UNITS(7.5, UNIT_1_25_MS) /**< Minimum connection interval (7.5 ms) */
#define MAX_CONN_INTERVAL MSEC_TO_UNITS(30, UNIT_1_25_MS)  /**< Maximum connection interval (30 ms). */
#define SLAVE_LATENCY 6                                    /**< Slave latency. */
#define CONN_SUP_TIMEOUT MSEC_TO_UNITS(430, UNIT_10_MS)    /**< Connection supervisory timeout (430 ms). */

#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 SEC_PARAM_BOND 1                               /**< Perform bonding. */
#define SEC_PARAM_MITM 0                               /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC 0                               /**< LE Secure Connections not 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 OUTPUT_REPORT_INDEX 0                 /**< Index of Output Report. */
#define OUTPUT_REPORT_MAX_LEN 1               /**< Maximum length of Output Report. */
#define INPUT_REPORT_KEYS_INDEX 0             /**< Index of Input Report. */
#define INPUT_CONTROL_KEYS_INDEX 1            /**< Index of Input Control Keys. */
#define OUTPUT_REPORT_BIT_MASK_CAPS_LOCK 0x02 /**< CAPS LOCK bit in Output Report (based on 'LED Page (0x08)' of the Universal Serial Bus HID Usage Tables). */
#define INPUT_REP_REF_ID 0                    /**< Id of reference to Keyboard Input Report. */
#define INPUT_CONTROL_REF_ID 2                /**< Id of reference to Keyboard Input Control Keys. */
#define OUTPUT_REP_REF_ID 0                   /**< Id of reference to Keyboard Output Report. */
#define FEATURE_REP_REF_ID 0                  /**< ID of reference to Keyboard Feature Report. */
#define FEATURE_REPORT_MAX_LEN 2              /**< Maximum length of Feature Report. */
#define FEATURE_REPORT_INDEX 0                /**< Index of Feature Report. */

#define MAX_BUFFER_ENTRIES 5 /**< Number of elements that can be enqueued */

#define BASE_USB_HID_SPEC_VERSION 0x0101 /**< Version number of base USB HID Specification implemented by this application. */

#define INPUT_REPORT_KEYS_MAX_LEN 8 /**< Maximum length of the Input Report characteristic. */
#define INPUT_CONTROL_KEYS_MAX_LEN 1 /**< Maximum length of the Input Control Key characteristic. */

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

#define SCHED_MAX_EVENT_DATA_SIZE APP_TIMER_SCHED_EVENT_DATA_SIZE /**< Maximum size of scheduler events. */
#ifdef SVCALL_AS_NORMAL_FUNCTION
#define SCHED_QUEUE_SIZE 20 /**< Maximum number of events in the scheduler queue. More is needed in case of Serialization. */
#else
#define SCHED_QUEUE_SIZE 10 /**< Maximum number of events in the scheduler queue. */
#endif

#define MODIFIER_KEY_POS 0  /**< Position of the modifier byte in the Input Report. */
#define SCAN_CODE_POS 2     /**< The start position of the key scan code in a HID Report. */
#define SHIFT_KEY_CODE 0x02 /**< Key code indicating the press of the Shift Key. */

#define MAX_KEYS_IN_ONE_REPORT (INPUT_REPORT_KEYS_MAX_LEN - SCAN_CODE_POS) /**< Maximum number of key presses that can be sent in one Input Report. */

//modification
pm_conn_sec_config_t conn_sec_config;

/**Buffer queue access macros
 *
 * @{ */
/** Initialization of buffer list */
#define BUFFER_LIST_INIT() \
  do {                     \
    buffer_list.rp = 0;    \
    buffer_list.wp = 0;    \
    buffer_list.count = 0; \
  } while (0)

/** Provide status of data list is full or not */
#define BUFFER_LIST_FULL() \
  ((MAX_BUFFER_ENTRIES == buffer_list.count - 1) ? true : false)

/** Provides status of buffer list is empty or not */
#define BUFFER_LIST_EMPTY() \
  ((0 == buffer_list.count) ? true : false)

#define BUFFER_ELEMENT_INIT(i)             \
  do {                                     \
    buffer_list.buffer[(i)].p_data = NULL; \
  } while (0)

/** @} */

/** Abstracts buffer element */
typedef struct hid_key_buffer {
  uint8_t data_offset;    /**< Max Data that can be buffered for all entries */
  uint8_t data_len;       /**< Total length of data */
  uint8_t *p_data;        /**< Scanned key pattern */
  ble_hids_t *p_instance; /**< Identifies peer and service instance */
} buffer_entry_t;

STATIC_ASSERT(sizeof(buffer_entry_t) % 4 == 0);

/** Circular buffer list */
typedef struct
{
  buffer_entry_t buffer[MAX_BUFFER_ENTRIES]; /**< Maximum number of entries that can enqueued in the list */
  uint8_t rp;                                /**< Index to the read location */
  uint8_t wp;                                /**< Index to write location */
  uint8_t count;                             /**< Number of elements in the list */
} buffer_list_t;

STATIC_ASSERT(sizeof(buffer_list_t) % 4 == 0);

APP_TIMER_DEF(m_battery_timer_id); /**< Battery timer. */
BLE_HIDS_DEF(m_hids,               /**< Structure used to identify the HID service. */
    NRF_SDH_BLE_TOTAL_LINK_COUNT,
    INPUT_REPORT_KEYS_MAX_LEN,
    OUTPUT_REPORT_MAX_LEN,
    FEATURE_REPORT_MAX_LEN);
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. */

static bool m_in_boot_mode = false;                      /**< Current protocol mode. */
static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID; /**< Handle of the current connection. */
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 bool m_caps_on = false;                           /**< Variable to indicate if Caps Lock is turned on. */
static pm_peer_id_t m_peer_id;                           /**< Device reference handle to the current bonded central. */
static buffer_list_t buffer_list;                        /**< List to enqueue not just data to be sent, but also related information like the handle, connection handle etc */

static ble_uuid_t m_adv_uuids[] = {{BLE_UUID_HUMAN_INTERFACE_DEVICE_SERVICE, BLE_UUID_TYPE_BLE}};

static uint8_t m_sample_key_press_scan_str[] = /**< Key pattern to be sent when the key press button has been pushed. */
    {
        0x0b, /* Key h */
        0x08, /* Key e */
        0x0f, /* Key l */
        0x0f, /* Key l */
        0x12, /* Key o */
        0x28  /* Key Return */
};

static uint8_t m_caps_on_key_scan_str[] = /**< Key pattern to be sent when the output report has been written with the CAPS LOCK bit set. */
    {
        0x06, /* Key C */
        0x04, /* Key a */
        0x13, /* Key p */
        0x16, /* Key s */
        0x12, /* Key o */
        0x11, /* Key n */
};

static uint8_t m_caps_off_key_scan_str[] = /**< Key pattern to be sent when the output report has been written with the CAPS LOCK bit cleared. */
    {
        0x06, /* Key C */
        0x04, /* Key a */
        0x13, /* Key p */
        0x16, /* Key s */
        0x12, /* Key o */
        0x09, /* Key f */
};

typedef enum {
  RELEASE_KEY = 0x00,
  CONSUMER_CTRL_PLAY = 0x01,
  CONSUMER_CTRL_ALCCC = 0x02,
  CONSUMER_CTRL_SCAN_NEXT_TRACK = 0x04,
  CONSUMER_CTRL_SCAN_PREV_TRACK = 0x08,
  CONSUMER_CTRL_VOL_DW = 0x10,
  CONSUMER_CTRL_VOL_UP = 0x20,
  CONSUMER_CTRL_AC_FORWARD = 0x40,
  CONSUMER_CTRL_AC_BACK = 0x80,
} consumer_control_t;

static void on_hids_evt(ble_hids_t *p_hids, ble_hids_evt_t *p_evt);

/**@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 Function for setting filtered whitelist.
 *
 * @param[in] skip  Filter passed to @ref pm_peer_id_list.
 */
static void whitelist_set(pm_peer_id_list_skip_t skip) {
  pm_peer_id_t peer_ids[BLE_GAP_WHITELIST_ADDR_MAX_COUNT];
  uint32_t peer_id_count = BLE_GAP_WHITELIST_ADDR_MAX_COUNT;

  ret_code_t err_code = pm_peer_id_list(peer_ids, &peer_id_count, PM_PEER_ID_INVALID, skip);
  APP_ERROR_CHECK(err_code);

  NRF_LOG_INFO("\tm_whitelist_peer_cnt %d, MAX_PEERS_WLIST %d",
      peer_id_count + 1,
      BLE_GAP_WHITELIST_ADDR_MAX_COUNT);

  err_code = pm_whitelist_set(peer_ids, peer_id_count);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for setting filtered device identities.
 *
 * @param[in] skip  Filter passed to @ref pm_peer_id_list.
 */
static void identities_set(pm_peer_id_list_skip_t skip) {
  pm_peer_id_t peer_ids[BLE_GAP_DEVICE_IDENTITIES_MAX_COUNT];
  uint32_t peer_id_count = BLE_GAP_DEVICE_IDENTITIES_MAX_COUNT;

  ret_code_t err_code = pm_peer_id_list(peer_ids, &peer_id_count, PM_PEER_ID_INVALID, skip);
  APP_ERROR_CHECK(err_code);

  err_code = pm_device_identities_list_set(peer_ids, peer_id_count);
  APP_ERROR_CHECK(err_code);
}

/**@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.
 */
static void advertising_start(bool erase_bonds) {
  if (erase_bonds == true) {
    delete_bonds();
    // Advertising is started by PM_EVT_PEERS_DELETE_SUCCEEDED event.
  } else {
    whitelist_set(PM_PEER_ID_LIST_SKIP_NO_ID_ADDR);

    ret_code_t ret = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(ret);
  }
}

/**@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;

  case PM_EVT_PEER_DATA_UPDATE_SUCCEEDED:
    if (p_evt->params.peer_data_update_succeeded.flash_changed && (p_evt->params.peer_data_update_succeeded.data_id == PM_PEER_DATA_ID_BONDING)) {
      NRF_LOG_INFO("New Bond, add the peer to the whitelist if possible");
      // Note: You should check on what kind of white list policy your application should use.

      whitelist_set(PM_PEER_ID_LIST_SKIP_NO_ID_ADDR);
    }
    break;
//modification
  case PM_EVT_CONN_SEC_CONFIG_REQ:
    NRF_LOG_INFO("CONN_SEC_REQ is called");
    conn_sec_config.allow_repairing = true;
    pm_conn_sec_config_reply(p_evt->conn_handle, &conn_sec_config);
    break;

  default:
    break;
  }
}

/**@brief Function for handling Service 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 service_error_handler(uint32_t nrf_error) {
  APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for handling advertising errors.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void ble_advertising_error_handler(uint32_t nrf_error) {
  APP_ERROR_HANDLER(nrf_error);
}

/**@brief Function for performing a battery measurement, and update the Battery Level characteristic in the 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_BUSY) &&
      (err_code != NRF_ERROR_RESOURCES) &&
      (err_code != NRF_ERROR_FORBIDDEN) &&
      (err_code != NRF_ERROR_INVALID_STATE) &&
      (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 the Timer initialization.
 *
 * @details Initializes the timer module.
 */
static void timers_init(void) {
  ret_code_t err_code;

  err_code = app_timer_init();
  APP_ERROR_CHECK(err_code);

  // Create battery timer.
  err_code = app_timer_create(&m_battery_timer_id,
      APP_TIMER_MODE_REPEATED,
      battery_level_meas_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_HID_KEYBOARD);
  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 initializing the GATT module.
 */
static void gatt_init(void) {
  ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, NULL);
  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 the Queued Write Module.
 */
static void qwr_init(void) {
  ret_code_t err_code;
  nrf_ble_qwr_init_t qwr_init_obj = {0};

  qwr_init_obj.error_handler = nrf_qwr_error_handler;

  err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init_obj);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing Device Information Service.
 */
static void dis_init(void) {
  ret_code_t err_code;
  ble_dis_init_t dis_init_obj;
  ble_dis_pnp_id_t pnp_id;

  pnp_id.vendor_id_source = PNP_ID_VENDOR_ID_SOURCE;
  pnp_id.vendor_id = PNP_ID_VENDOR_ID;
  pnp_id.product_id = PNP_ID_PRODUCT_ID;
  pnp_id.product_version = PNP_ID_PRODUCT_VERSION;

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

  ble_srv_ascii_to_utf8(&dis_init_obj.manufact_name_str, MANUFACTURER_NAME);
  dis_init_obj.p_pnp_id = &pnp_id;

  dis_init_obj.dis_char_rd_sec = SEC_JUST_WORKS;

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

/**@brief Function for initializing Battery Service.
 */
static void bas_init(void) {
  ret_code_t err_code;
  ble_bas_init_t bas_init_obj;

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

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

  bas_init_obj.bl_rd_sec = SEC_JUST_WORKS;
  bas_init_obj.bl_cccd_wr_sec = SEC_JUST_WORKS;
  bas_init_obj.bl_report_rd_sec = SEC_JUST_WORKS;

  err_code = ble_bas_init(&m_bas, &bas_init_obj);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing HID Service.
 */
static void hids_init(void) {
  ret_code_t err_code;
  ble_hids_init_t hids_init_obj;
  ble_hids_inp_rep_init_t *p_input_report;
  ble_hids_outp_rep_init_t *p_output_report;
  ble_hids_feature_rep_init_t *p_feature_report;
  uint8_t hid_info_flags;

  static ble_hids_inp_rep_init_t input_report_array[1];
  static ble_hids_outp_rep_init_t output_report_array[1];
  static ble_hids_feature_rep_init_t feature_report_array[1];
  static uint8_t report_map_data[] =
     {
          0x05, 0x01, // Usage Page (Generic Desktop)
          0x09, 0x06, // Usage (Keyboard)
          0xA1, 0x01, // Collection (Application)
          0x05, 0x07, // Usage Page (Key Codes)
          0x19, 0xe0, // Usage Minimum (224)
          0x29, 0xe7, // Usage Maximum (231)
          0x15, 0x00, // Logical Minimum (0)
          0x25, 0x01, // Logical Maximum (1)
          0x75, 0x01, // Report Size (1)
          0x95, 0x08, // Report Count (8)
          0x81, 0x02, // Input (Data, Variable, Absolute)

          0x95, 0x01, // Report Count (1)
          0x75, 0x08, // Report Size (8)
          0x81, 0x01, // Input (Constant) reserved byte(1)

          0x95, 0x05, // Report Count (5)
          0x75, 0x01, // Report Size (1)
          0x05, 0x08, // Usage Page (Page# for LEDs)
          0x19, 0x01, // Usage Minimum (1)
          0x29, 0x05, // Usage Maximum (5)
          0x91, 0x02, // Output (Data, Variable, Absolute), Led report
          0x95, 0x01, // Report Count (1)
          0x75, 0x03, // Report Size (3)
          0x91, 0x01, // Output (Data, Variable, Absolute), Led report padding

          0x95, 0x06, // Report Count (6)
          0x75, 0x08, // Report Size (8)
          0x15, 0x00, // Logical Minimum (0)
          0x25, 0x65, // Logical Maximum (101)
          0x05, 0x07, // Usage Page (Key codes)
          0x19, 0x00, // Usage Minimum (0)
          0x29, 0x65, // Usage Maximum (101)
          0x81, 0x00, // Input (Data, Array) Key array(6 bytes)

          0x09, 0x05,       // Usage (Vendor Defined)
          0x15, 0x00,       // Logical Minimum (0)
          0x26, 0xFF, 0x00, // Logical Maximum (255)
          0x75, 0x08,       // Report Size (8 bit)
          0x95, 0x02,       // Report Count (2)
          0xB1, 0x02,       // Feature (Data, Variable, Absolute)

          0xC0, // End Collection (Application)

          // Report ID 2: Advanced buttons
          0x05, 0x0C,                     // Usage Page (Consumer)
          0x09, 0x01,                     // Usage (Consumer Control)
          0xA1, 0x01,                     // Collection (Application)
          0x85, 0x02,                     //     Report Id (2)
          0x15, 0x00,                     //     Logical minimum (0)
          0x25, 0x01,                     //     Logical maximum (1)
          0x75, 0x01,                     //     Report Size (1)
          0x95, 0x01,                     //     Report Count (1)

          0x09, 0xCD,                     //     Usage (Play/Pause)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0x0A, 0x83, 0x01,               //     Usage (AL Consumer Control Configuration)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0x09, 0xB5,                     //     Usage (Scan Next Track)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0x09, 0xB6,                     //     Usage (Scan Previous Track)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)

          0x09, 0xEA,                     //     Usage (Volume Down)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0x09, 0xE9,                     //     Usage (Volume Up)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0x0A, 0x25, 0x02,               //     Usage (AC Forward)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0x0A, 0x24, 0x02,               //     Usage (AC Back)
          0x81, 0x02,                     //     Input (Data,Value,Relative,Bit Field)
          0xC0                            // End Collection		
      };

  memset((void *)input_report_array, 0, sizeof(ble_hids_inp_rep_init_t));
  memset((void *)output_report_array, 0, sizeof(ble_hids_outp_rep_init_t));
  memset((void *)feature_report_array, 0, sizeof(ble_hids_feature_rep_init_t));

  // Initialize HID Service
  p_input_report = &input_report_array[INPUT_REPORT_KEYS_INDEX];
  p_input_report->max_len = INPUT_REPORT_KEYS_MAX_LEN;
  p_input_report->rep_ref.report_id = INPUT_REP_REF_ID;
  p_input_report->rep_ref.report_type = BLE_HIDS_REP_TYPE_INPUT;

  p_input_report->sec.cccd_wr = SEC_JUST_WORKS;
  p_input_report->sec.wr = SEC_JUST_WORKS;
  p_input_report->sec.rd = SEC_JUST_WORKS;

  p_output_report = &output_report_array[OUTPUT_REPORT_INDEX];
  p_output_report->max_len = OUTPUT_REPORT_MAX_LEN;
  p_output_report->rep_ref.report_id = OUTPUT_REP_REF_ID;
  p_output_report->rep_ref.report_type = BLE_HIDS_REP_TYPE_OUTPUT;

  p_output_report->sec.wr = SEC_JUST_WORKS;
  p_output_report->sec.rd = SEC_JUST_WORKS;

  p_feature_report = &feature_report_array[FEATURE_REPORT_INDEX];
  p_feature_report->max_len = FEATURE_REPORT_MAX_LEN;
  p_feature_report->rep_ref.report_id = FEATURE_REP_REF_ID;
  p_feature_report->rep_ref.report_type = BLE_HIDS_REP_TYPE_FEATURE;

  p_feature_report->sec.rd = SEC_JUST_WORKS;
  p_feature_report->sec.wr = SEC_JUST_WORKS;

//  Initialize HID Service
  p_input_report = &input_report_array[INPUT_CONTROL_KEYS_INDEX];
  p_input_report->max_len = INPUT_CONTROL_KEYS_MAX_LEN;
  p_input_report->rep_ref.report_id = INPUT_CONTROL_REF_ID;
  p_input_report->rep_ref.report_type = BLE_HIDS_REP_TYPE_INPUT;

  p_input_report->sec.cccd_wr = SEC_JUST_WORKS;
  p_input_report->sec.wr = SEC_JUST_WORKS;
  p_input_report->sec.rd = SEC_JUST_WORKS;


  hid_info_flags = HID_INFO_FLAG_REMOTE_WAKE_MSK | HID_INFO_FLAG_NORMALLY_CONNECTABLE_MSK;

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

  hids_init_obj.evt_handler = on_hids_evt;
  hids_init_obj.error_handler = service_error_handler;
  hids_init_obj.is_kb = true;
  hids_init_obj.is_mouse = false;
  hids_init_obj.inp_rep_count = 1;
  hids_init_obj.p_inp_rep_array = input_report_array;
  hids_init_obj.outp_rep_count = 1;
  hids_init_obj.p_outp_rep_array = output_report_array;
  hids_init_obj.feature_rep_count = 1;
  hids_init_obj.p_feature_rep_array = feature_report_array;
  hids_init_obj.rep_map.data_len = sizeof(report_map_data);
  hids_init_obj.rep_map.p_data = report_map_data;
  hids_init_obj.hid_information.bcd_hid = BASE_USB_HID_SPEC_VERSION;
  hids_init_obj.hid_information.b_country_code = 0;
  hids_init_obj.hid_information.flags = hid_info_flags;
  hids_init_obj.included_services_count = 0;
  hids_init_obj.p_included_services_array = NULL;

  hids_init_obj.rep_map.rd_sec = SEC_JUST_WORKS;
  hids_init_obj.hid_information.rd_sec = SEC_JUST_WORKS;

  hids_init_obj.boot_kb_inp_rep_sec.cccd_wr = SEC_JUST_WORKS;
  hids_init_obj.boot_kb_inp_rep_sec.rd = SEC_JUST_WORKS;

  hids_init_obj.boot_kb_outp_rep_sec.rd = SEC_JUST_WORKS;
  hids_init_obj.boot_kb_outp_rep_sec.wr = SEC_JUST_WORKS;

  hids_init_obj.protocol_mode_rd_sec = SEC_JUST_WORKS;
  hids_init_obj.protocol_mode_wr_sec = SEC_JUST_WORKS;
  hids_init_obj.ctrl_point_wr_sec = SEC_JUST_WORKS;

  err_code = ble_hids_init(&m_hids, &hids_init_obj);
  APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing services that will be used by the application.
 */
static void services_init(void) {
  qwr_init();
  dis_init();
  bas_init();
  hids_init();
}

/**@brief Function for initializing the battery sensor simulator.
 */
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);
}

/**@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 = BLE_GATT_HANDLE_INVALID;
  cp_init.disconnect_on_fail = false;
  cp_init.evt_handler = NULL;
  cp_init.error_handler = conn_params_error_handler;

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

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

  err_code = app_timer_start(m_battery_timer_id, BATTERY_LEVEL_MEAS_INTERVAL, NULL);
  APP_ERROR_CHECK(err_code);
}

/**@brief   Function for transmitting a key scan Press & Release Notification.
 *
 * @warning This handler is an example only. You need to analyze how you wish to send the key
 *          release.
 *
 * @param[in]  p_instance     Identifies the service for which Key Notifications are requested.
 * @param[in]  p_key_pattern  Pointer to key pattern.
 * @param[in]  pattern_len    Length of key pattern. 0 < pattern_len < 7.
 * @param[in]  pattern_offset Offset applied to Key Pattern for transmission.
 * @param[out] actual_len     Provides actual length of Key Pattern transmitted, making buffering of
 *                            rest possible if needed.
 * @return     NRF_SUCCESS on success, NRF_ERROR_RESOURCES in case transmission could not be
 *             completed due to lack of transmission buffer or other error codes indicating reason
 *             for failure.
 *
 * @note       In case of NRF_ERROR_RESOURCES, remaining pattern that could not be transmitted
 *             can be enqueued \ref buffer_enqueue function.
 *             In case a pattern of 'cofFEe' is the p_key_pattern, with pattern_len as 6 and
 *             pattern_offset as 0, the notifications as observed on the peer side would be
 *             1>    'c', 'o', 'f', 'F', 'E', 'e'
 *             2>    -  , 'o', 'f', 'F', 'E', 'e'
 *             3>    -  ,   -, 'f', 'F', 'E', 'e'
 *             4>    -  ,   -,   -, 'F', 'E', 'e'
 *             5>    -  ,   -,   -,   -, 'E', 'e'
 *             6>    -  ,   -,   -,   -,   -, 'e'
 *             7>    -  ,   -,   -,   -,   -,  -
 *             Here, '-' refers to release, 'c' refers to the key character being transmitted.
 *             Therefore 7 notifications will be sent.
 *             In case an offset of 4 was provided, the pattern notifications sent will be from 5-7
 *             will be transmitted.
 */
static uint32_t send_key_scan_press_release(ble_hids_t *p_hids,
    uint8_t *p_key_pattern,
    uint16_t pattern_len,
    uint16_t pattern_offset,
    uint16_t *p_actual_len) {
  ret_code_t err_code;
  uint16_t offset;
  uint16_t data_len;
  uint8_t data[INPUT_REPORT_KEYS_MAX_LEN];

  // HID Report Descriptor enumerates an array of size 6, the pattern hence shall not be any
  // longer than this.
  STATIC_ASSERT((INPUT_REPORT_KEYS_MAX_LEN - 2) == 6);

  ASSERT(pattern_len <= (INPUT_REPORT_KEYS_MAX_LEN - 2));

  offset = pattern_offset;
  data_len = pattern_len;

  do {
    // Reset the data buffer.
    memset(data, 0, sizeof(data));

    // Copy the scan code.
    memcpy(data + SCAN_CODE_POS + offset, p_key_pattern + offset, data_len - offset);

    if (bsp_button_is_pressed(SHIFT_BUTTON_ID)) {
      data[MODIFIER_KEY_POS] |= SHIFT_KEY_CODE;
    }

    if (!m_in_boot_mode) {
      err_code = ble_hids_inp_rep_send(p_hids,
          INPUT_REPORT_KEYS_INDEX,
          INPUT_REPORT_KEYS_MAX_LEN,
          data,
          m_conn_handle);
    } else {
      err_code = ble_hids_boot_kb_inp_rep_send(p_hids,
          INPUT_REPORT_KEYS_MAX_LEN,
          data,
          m_conn_handle);
    }

    if (err_code != NRF_SUCCESS) {
      break;
    }

    offset++;
  } while (offset <= data_len);

  *p_actual_len = offset;

  return err_code;
}

/**@brief   Function for initializing the buffer queue used to key events that could not be
 *          transmitted
 *
 * @warning This handler is an example only. You need to analyze how you wish to buffer or buffer at
 *          all.
 *
 * @note    In case of HID keyboard, a temporary buffering could be employed to handle scenarios
 *          where encryption is not yet enabled or there was a momentary link loss or there were no
 *          Transmit buffers.
 */
static void buffer_init(void) {
  uint32_t buffer_count;

  BUFFER_LIST_INIT();

  for (buffer_count = 0; buffer_count < MAX_BUFFER_ENTRIES; buffer_count++) {
    BUFFER_ELEMENT_INIT(buffer_count);
  }
}

/**@brief Function for enqueuing key scan patterns that could not be transmitted either completely
 *        or partially.
 *
 * @warning This handler is an example only. You need to analyze how you wish to send the key
 *          release.
 *
 * @param[in]  p_hids         Identifies the service for which Key Notifications are buffered.
 * @param[in]  p_key_pattern  Pointer to key pattern.
 * @param[in]  pattern_len    Length of key pattern.
 * @param[in]  offset         Offset applied to Key Pattern when requesting a transmission on
 *                            dequeue, @ref buffer_dequeue.
 * @return     NRF_SUCCESS on success, else an error code indicating reason for failure.
 */
static uint32_t buffer_enqueue(ble_hids_t *p_hids,
    uint8_t *p_key_pattern,
    uint16_t pattern_len,
    uint16_t offset) {
  buffer_entry_t *element;
  uint32_t err_code = NRF_SUCCESS;

  if (BUFFER_LIST_FULL()) {
    // Element cannot be buffered.
    err_code = NRF_ERROR_NO_MEM;
  } else {
    // Make entry of buffer element and copy data.
    element = &buffer_list.buffer[(buffer_list.wp)];
    element->p_instance = p_hids;
    element->p_data = p_key_pattern;
    element->data_offset = offset;
    element->data_len = pattern_len;

    buffer_list.count++;
    buffer_list.wp++;

    if (buffer_list.wp == MAX_BUFFER_ENTRIES) {
      buffer_list.wp = 0;
    }
  }

  return err_code;
}

/**@brief   Function to dequeue key scan patterns that could not be transmitted either completely of
 *          partially.
 *
 * @warning This handler is an example only. You need to analyze how you wish to send the key
 *          release.
 *
 * @param[in]  tx_flag   Indicative of whether the dequeue should result in transmission or not.
 * @note       A typical example when all keys are dequeued with transmission is when link is
 *             disconnected.
 *
 * @return     NRF_SUCCESS on success, else an error code indicating reason for failure.
 */
static uint32_t buffer_dequeue(bool tx_flag) {
  buffer_entry_t *p_element;
  uint32_t err_code = NRF_SUCCESS;
  uint16_t actual_len;

  if (BUFFER_LIST_EMPTY()) {
    err_code = NRF_ERROR_NOT_FOUND;
  } else {
    bool remove_element = true;

    p_element = &buffer_list.buffer[(buffer_list.rp)];

    if (tx_flag) {
      err_code = send_key_scan_press_release(p_element->p_instance,
          p_element->p_data,
          p_element->data_len,
          p_element->data_offset,
          &actual_len);
      // An additional notification is needed for release of all keys, therefore check
      // is for actual_len <= element->data_len and not actual_len < element->data_len
      if ((err_code == NRF_ERROR_RESOURCES) && (actual_len <= p_element->data_len)) {
        // Transmission could not be completed, do not remove the entry, adjust next data to
        // be transmitted
        p_element->data_offset = actual_len;
        remove_element = false;
      }
    }

    if (remove_element) {
      BUFFER_ELEMENT_INIT(buffer_list.rp);

      buffer_list.rp++;
      buffer_list.count--;

      if (buffer_list.rp == MAX_BUFFER_ENTRIES) {
        buffer_list.rp = 0;
      }
    }
  }

  return err_code;
}

/**@brief Function for sending sample key presses to the peer.
 *
 * @param[in]   key_pattern_len   Pattern length.
 * @param[in]   p_key_pattern     Pattern to be sent.
 */
static void keys_send(uint8_t key_pattern_len, uint8_t *p_key_pattern) {
  ret_code_t err_code;
  uint16_t actual_len;

  err_code = send_key_scan_press_release(&m_hids,
      p_key_pattern,
      key_pattern_len,
      0,
      &actual_len);
  // An additional notification is needed for release of all keys, therefore check
  // is for actual_len <= key_pattern_len and not actual_len < key_pattern_len.
  if ((err_code == NRF_ERROR_RESOURCES) && (actual_len <= key_pattern_len)) {
    // Buffer enqueue routine return value is not intentionally checked.
    // Rationale: Its better to have a a few keys missing than have a system
    // reset. Recommendation is to work out most optimal value for
    // MAX_BUFFER_ENTRIES to minimize chances of buffer queue full condition
    UNUSED_VARIABLE(buffer_enqueue(&m_hids, p_key_pattern, key_pattern_len, actual_len));
  }

  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 HID Report Characteristic Write event.
 *
 * @param[in]   p_evt   HID service event.
 */
static void on_hid_rep_char_write(ble_hids_evt_t *p_evt) {
  if (p_evt->params.char_write.char_id.rep_type == BLE_HIDS_REP_TYPE_OUTPUT) {
    ret_code_t err_code;
    uint8_t report_val;
    uint8_t report_index = p_evt->params.char_write.char_id.rep_index;

    if (report_index == OUTPUT_REPORT_INDEX) {
      // This code assumes that the output report is one byte long. Hence the following
      // static assert is made.
      STATIC_ASSERT(OUTPUT_REPORT_MAX_LEN == 1);

      err_code = ble_hids_outp_rep_get(&m_hids,
          report_index,
          OUTPUT_REPORT_MAX_LEN,
          0,
          m_conn_handle,
          &report_val);
      APP_ERROR_CHECK(err_code);

      if (!m_caps_on && ((report_val & OUTPUT_REPORT_BIT_MASK_CAPS_LOCK) != 0)) {
        // Caps Lock is turned On.
        NRF_LOG_INFO("Caps Lock is turned On!");
        err_code = bsp_indication_set(BSP_INDICATE_ALERT_3);
        APP_ERROR_CHECK(err_code);

        keys_send(sizeof(m_caps_on_key_scan_str), m_caps_on_key_scan_str);
        m_caps_on = true;
      } else if (m_caps_on && ((report_val & OUTPUT_REPORT_BIT_MASK_CAPS_LOCK) == 0)) {
        // Caps Lock is turned Off .
        NRF_LOG_INFO("Caps Lock is turned Off!");
        err_code = bsp_indication_set(BSP_INDICATE_ALERT_OFF);
        APP_ERROR_CHECK(err_code);

        keys_send(sizeof(m_caps_off_key_scan_str), m_caps_off_key_scan_str);
        m_caps_on = false;
      } else {
        // The report received is not supported by this application. Do nothing.
      }
    }
  }
}

/**@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 HID events.
 *
 * @details This function will be called for all HID events which are passed to the application.
 *
 * @param[in]   p_hids  HID service structure.
 * @param[in]   p_evt   Event received from the HID service.
 */
static void on_hids_evt(ble_hids_t *p_hids, ble_hids_evt_t *p_evt) {
  switch (p_evt->evt_type) {
  case BLE_HIDS_EVT_BOOT_MODE_ENTERED:
    m_in_boot_mode = true;
    break;

  case BLE_HIDS_EVT_REPORT_MODE_ENTERED:
    m_in_boot_mode = false;
    break;

  case BLE_HIDS_EVT_REP_CHAR_WRITE:
    on_hid_rep_char_write(p_evt);
    break;

  case BLE_HIDS_EVT_NOTIF_ENABLED:
    break;

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

/**@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_DIRECTED_HIGH_DUTY:
    NRF_LOG_INFO("High Duty Directed advertising.");
    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING_DIRECTED);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_ADV_EVT_DIRECTED:
    NRF_LOG_INFO("Directed advertising.");
    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING_DIRECTED);
    APP_ERROR_CHECK(err_code);
    break;

  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_SLOW:
    NRF_LOG_INFO("Slow advertising.");
    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING_SLOW);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_ADV_EVT_FAST_WHITELIST:
    NRF_LOG_INFO("Fast advertising with whitelist.");
    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING_WHITELIST);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_ADV_EVT_SLOW_WHITELIST:
    NRF_LOG_INFO("Slow advertising with whitelist.");
    err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING_WHITELIST);
    APP_ERROR_CHECK(err_code);
    break;

  case BLE_ADV_EVT_IDLE:
    sleep_mode_enter();
    break;

  case BLE_ADV_EVT_WHITELIST_REQUEST: {
    ble_gap_addr_t whitelist_addrs[BLE_GAP_WHITELIST_ADDR_MAX_COUNT];
    ble_gap_irk_t whitelist_irks[BLE_GAP_WHITELIST_ADDR_MAX_COUNT];
    uint32_t addr_cnt = BLE_GAP_WHITELIST_ADDR_MAX_COUNT;
    uint32_t irk_cnt = BLE_GAP_WHITELIST_ADDR_MAX_COUNT;

    err_code = pm_whitelist_get(whitelist_addrs, &addr_cnt,
        whitelist_irks, &irk_cnt);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_DEBUG("pm_whitelist_get returns %d addr in whitelist and %d irk whitelist",
        addr_cnt, irk_cnt);

    // Set the correct identities list (no excluding peers with no Central Address Resolution).
    identities_set(PM_PEER_ID_LIST_SKIP_NO_IRK);

    // Apply the whitelist.
    err_code = ble_advertising_whitelist_reply(&m_advertising,
        whitelist_addrs,
        addr_cnt,
        whitelist_irks,
        irk_cnt);
    APP_ERROR_CHECK(err_code);
  } break; //BLE_ADV_EVT_WHITELIST_REQUEST

  case BLE_ADV_EVT_PEER_ADDR_REQUEST: {
    pm_peer_data_bonding_t peer_bonding_data;

    // Only Give peer address if we have a handle to the bonded peer.
    if (m_peer_id != PM_PEER_ID_INVALID) {
      err_code = pm_peer_data_bonding_load(m_peer_id, &peer_bonding_data);
      if (err_code != NRF_ERROR_NOT_FOUND) {
        APP_ERROR_CHECK(err_code);

        // Manipulate identities to exclude peers with no Central Address Resolution.
        identities_set(PM_PEER_ID_LIST_SKIP_ALL);

        ble_gap_addr_t *p_peer_addr = &(peer_bonding_data.peer_ble_id.id_addr_info);
        err_code = ble_advertising_peer_addr_reply(&m_advertising, p_peer_addr);
        APP_ERROR_CHECK(err_code);
      }
    }
  } break; //BLE_ADV_EVT_PEER_ADDR_REQUEST

  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");
    // Dequeue all keys without transmission.
    (void)buffer_dequeue(false);

    m_conn_handle = BLE_CONN_HANDLE_INVALID;

    // Reset m_caps_on variable. Upon reconnect, the HID host will re-send the Output
    // report containing the Caps lock state.
    m_caps_on = false;
    // disabling alert 3. signal - used for capslock ON
    err_code = bsp_indication_set(BSP_INDICATE_ALERT_OFF);
    APP_ERROR_CHECK(err_code);

    break; // BLE_GAP_EVT_DISCONNECTED

  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_GATTS_EVT_HVN_TX_COMPLETE:
    // Send next key event
    (void)buffer_dequeue(true);
    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:
    // 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 the Event Scheduler initialization.
 */
static void scheduler_init(void) {
  APP_SCHED_INIT(SCHED_MAX_EVENT_DATA_SIZE, SCHED_QUEUE_SIZE);
}

/**@brief Function for sending consumer control data
 */
static uint32_t consumer_control_send(consumer_control_t cmd) {
  return ble_hids_inp_rep_send(&m_hids, INPUT_CONTROL_KEYS_INDEX, INPUT_CONTROL_KEYS_MAX_LEN, (uint8_t *)&cmd, m_conn_handle);
}

/**@brief Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
static void bsp_event_handler(bsp_event_t event) {
  uint32_t err_code;
  static uint8_t *p_key = m_sample_key_press_scan_str;
  static uint8_t size = 0;

  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;

  case BSP_EVENT_KEY_0:
    printf("Button 1 pressed");
    if (m_conn_handle != BLE_CONN_HANDLE_INVALID) {
      keys_send(1, p_key);
      p_key++;
      size++;
      if (size == MAX_KEYS_IN_ONE_REPORT) {
        p_key = m_sample_key_press_scan_str;
        size = 0;
      }
    }
    break;
  case BSP_EVENT_KEY_2:
    printf("Button 3 pressed");
    if (m_conn_handle != BLE_CONN_HANDLE_INVALID) {
      APP_ERROR_CHECK(consumer_control_send(CONSUMER_CTRL_VOL_DW));
    }
    break;
  case BSP_EVENT_KEY_3:
    printf("Button 4 pressed");
    if (m_conn_handle != BLE_CONN_HANDLE_INVALID) {
      APP_ERROR_CHECK(consumer_control_send(CONSUMER_CTRL_VOL_UP));
    }
    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) {
  uint32_t err_code;
  uint8_t adv_flags;
  ble_advertising_init_t init;

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

  adv_flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
  init.advdata.name_type = BLE_ADVDATA_FULL_NAME;
  init.advdata.include_appearance = true;
  init.advdata.flags = adv_flags;
  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_whitelist_enabled = true;
  init.config.ble_adv_directed_high_duty_enabled = true;
  init.config.ble_adv_directed_enabled = false;
  init.config.ble_adv_directed_interval = 0;
  init.config.ble_adv_directed_timeout = 0;
  init.config.ble_adv_fast_enabled = true;
  init.config.ble_adv_fast_interval = APP_ADV_FAST_INTERVAL;
  init.config.ble_adv_fast_timeout = APP_ADV_FAST_DURATION;
  init.config.ble_adv_slow_enabled = true;
  init.config.ble_adv_slow_interval = APP_ADV_SLOW_INTERVAL;
  init.config.ble_adv_slow_timeout = APP_ADV_SLOW_DURATION;

  init.evt_handler = on_adv_evt;
  init.error_handler = ble_advertising_error_handler;

  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) {
  app_sched_execute();
  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();
  scheduler_init();
  gap_params_init();
  gatt_init();
  advertising_init();
  services_init();
  sensor_simulator_init();
  conn_params_init();
  buffer_init();
  peer_manager_init();

  // Start execution.
  NRF_LOG_INFO("HID Keyboard example started.");
  timers_start();
  advertising_start(erase_bonds);

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

/**
 * @}
 */

Parents
  • Hi,

    It seems like the error code is 0x07 (NRF_ERROR_INVALID_PARAM), and that this comes from the call to ble_hids_inp_rep_send() in consumer_control_send(). Looking at the source code in the SDK, this function will return this error if the rep_index parameter is not smaller than the configured p_hids->inp_rep_count.

    In your hids_init() function, you set the count to 1 (hids_init_obj.inp_rep_count = 1), while you have defined INPUT_CONTROL_KEYS:INDEX to be 1 (i.e. not smaller than 1). Increasing the config should solve this issue.

    Best regards,
    Jørgen

Reply
  • Hi,

    It seems like the error code is 0x07 (NRF_ERROR_INVALID_PARAM), and that this comes from the call to ble_hids_inp_rep_send() in consumer_control_send(). Looking at the source code in the SDK, this function will return this error if the rep_index parameter is not smaller than the configured p_hids->inp_rep_count.

    In your hids_init() function, you set the count to 1 (hids_init_obj.inp_rep_count = 1), while you have defined INPUT_CONTROL_KEYS:INDEX to be 1 (i.e. not smaller than 1). Increasing the config should solve this issue.

    Best regards,
    Jørgen

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