text: /**
   * Copyright (c) 2017 - 2020, Nordic Semiconductor ASA
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
   *    such product, must reproduce the above copyright notice, this list of
   *    conditions and the following disclaimer in the documentation and/or other
   *    materials provided with the distribution.
   *
   * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
   *    contributors may be used to endorse or promote products derived from this
   *    software without specific prior written permission.
   *
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
   *
   * 5. Any software provided in binary form under this license must not be reverse
   *    engineered, decompiled, modified and/or disassembled.
   *
   * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
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   * 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 "ble.h"
  #include "ble_hci.h"
  #include "ble_srv_common.h"
  #include "ble_advdata.h"
  #include "ble_advertising.h"
  #include "ble_bas.h"
  #include "ble_dis.h"
  #include "boards.h"
  #include "sensorsim.h"
  #include "nrf_sdh.h"
  #include "nrf_sdh_soc.h"
  #include "nrf_sdh_ble.h"
  #include "bsp.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_qwr.h"
  #include "ble_conn_state.h"
  
  #include "app_error.h"
  #include "app_timer.h"
  #include "task_manager.h"
  #include "nrf_cli.h"
  #include "nrf_cli_rtt.h"
  #include "nrf_cli_uart.h"
  #include "nrf_cli_ble_uart.h"
  #include "nrf_pwr_mgmt.h"
  #include "nrf_drv_clock.h"
  #include "nrf_stack_guard.h"
  #include "nrf_fstorage_sd.h"
  
  #include "nrf_log.h"
  #include "nrf_log_ctrl.h"
  #include "nrf_log_backend_flash.h"
  
  
  #define DEVICE_NAME                     "Nordic_CLI"                                /**< 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_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 7battery level. */
  #define BATTERY_LEVEL_INCREMENT          1                                          /**< Increment between each simulated battery level measurement. */
  
  #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 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 DEAD_BEEF                       0xDEADBEEF                                  /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */
  
  BLE_BAS_DEF(m_bas);                                                                 /**< Battery service instance. */
  NRF_BLE_GATT_DEF(m_gatt);                                                           /**< GATT module instance. */
  NRF_BLE_QWR_DEF(m_qwr);                                                             /**< Context for the Queued Write module.*/
  BLE_ADVERTISING_DEF(m_advertising);                                                 /**< Advertising module instance. */
  APP_TIMER_DEF(m_battery_timer_id);                                                  /**< Battery timer. */
  
  NRF_CLI_RTT_DEF(cli_rtt);
  NRF_CLI_UART_DEF(cli_uart,0 , 256, 16);
  NRF_CLI_BLE_UART_DEF(cli_ble_uart, &m_gatt, 64, 32);
  NRF_CLI_DEF(m_cli, "rtt_cli:~$ ", &cli_rtt.transport,'\r', 4);
  NRF_CLI_DEF(m_cli_uart, "uart_cli:~$ ", &cli_uart.transport,'\r', 4);
  NRF_CLI_DEF(m_ble_cli, "ble_cli:~$ ", &cli_ble_uart.transport,'\r', 8);
  
  NRF_LOG_BACKEND_FLASHLOG_DEF(m_flash_log_backend);
  NRF_LOG_BACKEND_CRASHLOG_DEF(m_crash_log_backend);
  
  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. */
  
  task_id_t m_ble_console_task_id;
  
  static ble_uuid_t m_adv_uuids[] =                                                   /**< Universally unique service identifiers. */
  {
      {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 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);
  
      memset(&gap_conn_params, 0, sizeof(gap_conn_params));
  
      gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
      gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
      gap_conn_params.slave_latency     = SLAVE_LATENCY;
      gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;
  
      err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
      APP_ERROR_CHECK(err_code);
  }
  
  /**@brief Function for handling events from the GATT library. */
  void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
  {
      NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                    p_gatt->att_mtu_desired_central,
                    p_gatt->att_mtu_desired_periph);
  }
  
  
  /**@brief Function for initializing the GATT 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_bas_init_t     bas_init;
      ble_dis_init_t     dis_init;
      nrf_ble_qwr_init_t qwr_init = {0};
  
      // Initialize Queued Write Module.
      qwr_init.error_handler = nrf_qwr_error_handler;
  
      err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
      APP_ERROR_CHECK(err_code);
  
      // Initialize Battery Service.
      memset(&bas_init, 0, sizeof(bas_init));
  
      // 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;
  
      bas_init.evt_handler          = NULL;
      bas_init.support_notification = true;
      bas_init.p_report_ref         = NULL;
      bas_init.initial_batt_level   = 100;
  
      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 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:
              nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_SYSOFF);
              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);
  
              nrf_cli_ble_uart_config_t config = { .conn_handle = m_conn_handle };
  
              err_code = nrf_cli_init(&m_ble_cli, &config, true, true, NRF_LOG_SEVERITY_INFO);
              APP_ERROR_CHECK(nrf_cli_task_create(&m_ble_cli));
  
              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;
              (void)nrf_cli_uninit(&m_ble_cli);
              break;
  
          case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
          {
              NRF_LOG_DEBUG("PHY update request.");
              ble_gap_phys_t const phys =
              {
                  .rx_phys = BLE_GAP_PHY_AUTO,
                  .tx_phys = BLE_GAP_PHY_AUTO,
              };
              err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
              APP_ERROR_CHECK(err_code);
          } break;
  
          case BLE_GATTC_EVT_TIMEOUT:
              // Disconnect on GATT Client timeout event.
              NRF_LOG_DEBUG("GATT Client Timeout.");
              err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                               BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
              APP_ERROR_CHECK(err_code);
              break;
  
          case BLE_GATTS_EVT_TIMEOUT:
              // Disconnect on GATT Server timeout event.
              NRF_LOG_DEBUG("GATT Server Timeout.");
              err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                               BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
              APP_ERROR_CHECK(err_code);
              break;
  
          default:
              // No implementation needed.
              break;
      }
  }
  
  /**@brief Function for the SoftDevice initialization.
   *
   * @details This function initializes the SoftDevice and the BLE event interrupt.
   */
  static void ble_stack_init(void)
  {
      ret_code_t err_code;
  
      err_code = nrf_sdh_enable_request();
      APP_ERROR_CHECK(err_code);
  
      // Configure the BLE stack using the default settings.
      // Fetch the start address of the application RAM.
      uint32_t ram_start = 0;
      err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
      APP_ERROR_CHECK(err_code);
  
      // Enable BLE stack.
      err_code = nrf_sdh_ble_enable(&ram_start);
      APP_ERROR_CHECK(err_code);
  
      // Register a handler for BLE events.
      NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
  }
  
  
  /**@brief Function for handling events from the BSP module.
   *
   * @param[in]   event   Event generated by button press.
   */
  void bsp_event_handler(bsp_event_t event)
  {
      ret_code_t err_code;
  
      switch (event)
      {
          case BSP_EVENT_SLEEP:
              nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_SYSOFF);
              break;
  
          case BSP_EVENT_DISCONNECT:
              err_code = sd_ble_gap_disconnect(m_conn_handle,
                                               BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
              if (err_code != NRF_ERROR_INVALID_STATE)
              {
                  APP_ERROR_CHECK(err_code);
              }
              break;
  
          case BSP_EVENT_WHITELIST_OFF:
              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.io_caps        = SEC_PARAM_IO_CAPABILITIES;
      sec_param.oob            = SEC_PARAM_OOB;
      sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
      sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
      sec_param.kdist_own.enc  = 1;
      sec_param.kdist_own.id   = 1;
      sec_param.kdist_peer.enc = 1;
      sec_param.kdist_peer.id  = 1;
  
      err_code = pm_sec_params_set(&sec_param);
      APP_ERROR_CHECK(err_code);
  
      err_code = pm_register(pm_evt_handler);
      APP_ERROR_CHECK(err_code);
  }
  
  
  /**@brief Function for initializing the Advertising functionality.
   */
  static void advertising_init(void)
  {
      ret_code_t             err_code;
      ble_advertising_init_t init;
  
      memset(&init, 0, sizeof(init));
  
      init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
      init.advdata.include_appearance      = true;
      init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
      init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
      init.advdata.uuids_complete.p_uuids  = m_adv_uuids;
  
      init.config.ble_adv_fast_enabled  = true;
      init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
      init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;
  
      init.evt_handler = on_adv_evt;
  
      err_code = ble_advertising_init(&m_advertising, &init);
      APP_ERROR_CHECK(err_code);
  
      ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
  }
  
  /** @brief Function for initializing BLE components.
   */
  void ble_init(void)
  {
      ble_stack_init();
      gap_params_init();
      gatt_init();
      advertising_init();
      services_init();
      peer_manager_init();
  }
  
  
  /**@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 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);
  
      ret_code_t err_code;
      uint8_t  battery_level;
  
      battery_level = (uint8_t)sensorsim_measure(&m_battery_sim_state, &m_battery_sim_cfg);
  
      NRF_LOG_INFO("Battery level update: %d", battery_level);
      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 initialization of ticker for periodical battery measurement.
   */
  static void battery_measurement_init(void)
  {
      ret_code_t err_code;
  
      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);
  
      // 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);
  }
  
  /**@brief Function for starting batter measurement timers.
   */
  static void battery_measurement_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);
  }
  
  /**
   * @brief Function for shutdown events.
   *
   * @param[in]   event       Shutdown type.
   */
  static bool shutdown_handler(nrf_pwr_mgmt_evt_t event)
  {
      ret_code_t err_code;
  
      err_code = bsp_indication_set(BSP_INDICATE_IDLE);
      APP_ERROR_CHECK(err_code);
  
      switch (event)
      {
          case NRF_PWR_MGMT_EVT_PREPARE_WAKEUP:
              // Prepare wakeup buttons.
              err_code = bsp_btn_ble_sleep_mode_prepare();
              APP_ERROR_CHECK(err_code);
              break;
          default:
              break;
      }
  
      return true;
  }
  
  NRF_PWR_MGMT_HANDLER_REGISTER(shutdown_handler, 0);
  
  static void led_on_cmd(nrf_cli_t const *p_cli, size_t argc, char **argv)
  {
      bsp_board_led_on(3);
      nrf_cli_fprintf(p_cli, NRF_CLI_NORMAL, "LED turned on.\n");
  }
  
  static void led_off_cmd(nrf_cli_t const *p_cli, size_t argc, char **argv)
  {
      bsp_board_led_off(3);
      nrf_cli_fprintf(p_cli, NRF_CLI_NORMAL, "LED turned off.\n");
  }
  
  static void default_cmd(nrf_cli_t const *p_cli, size_t argc, char **argv)
  {
      if ((argc == 1) || nrf_cli_help_requested(p_cli))
      {
          nrf_cli_help_print(p_cli, NULL, 0);
          return;
      }
  
      nrf_cli_fprintf(p_cli, NRF_CLI_ERROR, "%s:%s%s\n", argv[0], " unknown parameter: ", argv[1]);
  }
  
  
  // Register "mpu" command and it's subcommands in CLI.
  NRF_CLI_CREATE_STATIC_SUBCMD_SET(led_commands)
  {
       NRF_CLI_CMD(on, NULL, "Turn LED on.", led_on_cmd),
       NRF_CLI_CMD(off, NULL, "Turn LED off.", led_off_cmd),
       NRF_CLI_SUBCMD_SET_END
  };
  
  NRF_CLI_CMD_REGISTER(led, &led_commands, "Commands for LED control", default_cmd);
  
  void idle_task(void * p_context)
  {
  
      bool erase_bonds = (bool)p_context;
      battery_measurement_start();
  
      advertising_start(erase_bonds);
  
      // Enter main loop.
      for (;;)
      {
          if (NRF_LOG_PROCESS() == false)
          {
              nrf_pwr_mgmt_run();
          }
          task_yield();
      }
  
  }
  
  static void flashlog_init(void)
  {
      ret_code_t ret;
      int32_t backend_id;
      
      ret = nrf_log_backend_flash_init(&nrf_fstorage_sd);
      APP_ERROR_CHECK(ret);
  
      backend_id = nrf_log_backend_add(&m_flash_log_backend, NRF_LOG_SEVERITY_WARNING);
      APP_ERROR_CHECK_BOOL(backend_id >= 0);
  
      backend_id = nrf_log_backend_add(&m_crash_log_backend, NRF_LOG_SEVERITY_INFO);
      APP_ERROR_CHECK_BOOL(backend_id >= 0);
  
      nrf_log_backend_enable(&m_flash_log_backend);
      nrf_log_backend_enable(&m_crash_log_backend);
  }
  
  static void core_init(void)
  {
      APP_ERROR_CHECK(NRF_LOG_INIT(app_timer_cnt_get));
  
      if (CoreDebug->DHCSR & CoreDebug_DHCSR_C_DEBUGEN_Msk)
      {
          APP_ERROR_CHECK(nrf_cli_init(&m_cli, NULL, true, true, NRF_LOG_SEVERITY_INFO));
      }
  
      nrf_drv_uart_config_t uart_config = NRF_DRV_UART_DEFAULT_CONFIG;
      uart_config.pseltxd = TX_PIN_NUMBER;
      uart_config.pselrxd = RX_PIN_NUMBER;
      uart_config.hwfc    = NRF_UART_HWFC_DISABLED;
      APP_ERROR_CHECK(nrf_cli_init(&m_cli_uart, &uart_config, true, true, NRF_LOG_SEVERITY_INFO));
  
      APP_ERROR_CHECK(nrf_drv_clock_init());
  
      nrf_drv_clock_lfclk_request(NULL);
  
      APP_ERROR_CHECK(app_timer_init());
  
      APP_ERROR_CHECK(nrf_stack_guard_init());
  
      APP_ERROR_CHECK(nrf_pwr_mgmt_init());
  
      if (CoreDebug->DHCSR & CoreDebug_DHCSR_C_DEBUGEN_Msk)
      {
          APP_ERROR_CHECK(nrf_cli_task_create(&m_cli));
      }
  
      APP_ERROR_CHECK(nrf_cli_task_create(&m_cli_uart));
  }
  
  
  /**@brief Function for application main entry.
   */
  int main(void)
  
  {
      bool erase_bonds;
  
      core_init();
  
      buttons_leds_init(&erase_bonds);
  
      ble_init();
  
      flashlog_init();
  
      battery_measurement_init();
  
      APP_ERROR_CHECK(nrf_cli_ble_uart_service_init());
  
      NRF_LOG_INFO("BLE CLI example started.");
  
      task_manager_start(idle_task, (void *)erase_bonds);
  }
  