Direct connection after disconnect

[RYYoo]

Direct connection after disconnect
            
I am using the iPhone 8,  BLE device (51822/51422), s130, SDK 12.3.0.

and using a bonding and passkey to connect.

However, Direct connection after disconnect
            
For example,
            
1.
   - At first connection, it is connected and the passkey input window appears.
   - Press the cancel button.
   - Disconnected.
   - However, it is reconnected immediately and the passkey input window appears again.
   - After this, if i press cancel button or input wrongly, disconnect, and then the input window appears immediately after connection.

2.
   - After entering the passkey, connect and disconnect normally. (In this case, after disconnect , it normally advertises)
   - Delete the bond erase in device (keep the phone's bond information intact)
   - If i try to connect, it will fail because it does not have the device's bond information. (normal)
   - But... After I disconnect, I just want to advertise. However, as soon as the advertisement is disconnected, direct connection - failure - disconnect - advertisement - connection - failure -  disconnect  - advertisement... repeats itself.

[RYYoo]

Fullscreen 71251.main.c Download

/**
 * Copyright (c) 2015 - 2017, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/**
 * @brief Blinky Sample Application main file.
 *
 * This file contains the source code for a sample server application using the LED Button service.
 */

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "DeviceVersion.h"
#include "nordic_common.h"
#include "nrf.h"
#include "app_error.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_gap.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "nrf_gpio.h"
#include "softdevice_handler.h"
#include "ble_srv_common.h"
#include "ble_conn_params.h"
#include "boards.h"
#include "app_timer.h"
#include "fstorage.h"
#include "fds.h"
#include "ble_lls.h"
#include "peer_manager.h"
#include "app_button.h"
#include "bsp.h"
#include "peer_manager.h"
#include "softdevice_handler.h"
#include "bsp_btn_ble.h"
#include "ble_conn_state.h"
#include "nrf_drv_rng.h"
#include "nrf_drv_gpiote.h"
#include "app_uart.h"
#include "nrf_drv_uart.h"
#include "app_util_platform.h"
#include "ble_nus.h"
#include "ble_lbs.h"
#include "ble_dis.h"
#define NRF_LOG_MODULE_NAME "APP"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"



#define GPIO_PIN_HIGH                   1
#define GPIO_PIN_LOW                    0

#define CENTRAL_LINK_COUNT              0                                           /**< Number of central links used by the application. When changing this number remember to adjust the RAM settings*/
#define PERIPHERAL_LINK_COUNT           1                                           /**< Number of peripheral links used by the application. When changing this number remember to adjust the RAM settings*/

#if (NRF_SD_BLE_API_VERSION == 3)
#define NRF_BLE_MAX_MTU_SIZE            GATT_MTU_SIZE_DEFAULT                       /**< MTU size used in the softdevice enabling and to reply to a BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST event. */
#endif

#define APP_FEATURE_NOT_SUPPORTED       BLE_GATT_STATUS_ATTERR_APP_BEGIN + 2        /**< Reply when unsupported features are requested. */

#define ADVERTISING_LED_PIN             BSP_BOARD_LED_0                             /**< Is on when device is advertising. */
#define CONNECTED_LED_PIN               BSP_BOARD_LED_1                             /**< Is on when device has connected. */


#define BT_CONN_PIN                     2
#define BT_RESET_PIN                    1
#define DEBOUNCE_INIT_PIN               200

#define DEVICE_NAME                     "example"                                 /**< Name of device. Will be included in the advertising data. */

#define APP_ADV_INTERVAL                64                                          /**< The advertising interval (in units of 0.625 ms; this value corresponds to 40 ms). */
#define APP_ADV_TIMEOUT_IN_SECONDS      BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED       /**< The advertising time-out (in units of seconds). When set to 0, we will never time out. */

#define APP_TIMER_PRESCALER             0                                           /**< Value of the RTC1 PRESCALER register. */
#define APP_TIMER_MAX_TIMERS            6                                           /**< Maximum number of simultaneously created timers. */
#define APP_TIMER_OP_QUEUE_SIZE         6                                           /**< Size of timer operation queues. */

//#define SECURITY_REQUEST_DELAY        APP_TIMER_TICKS(4000, APP_TIMER_PRESCALER)  //!< Delay after connection until Security Request is sent, if necessary (ticks). */
//#define MCU_RESPONSE_DELAY            APP_TIMER_TICKS(500, APP_TIMER_PRESCALER)   /**< Timer delay to detect response(MCU) to passkey  */
#define SECURITY_REQUEST_DELAY          APP_TIMER_TICKS(400, APP_TIMER_PRESCALER)   /**< Delay after connection until Security Request is sent, if necessary (ticks). */
#define SYSTEM_TIMER_DELAY              APP_TIMER_TICKS(10, APP_TIMER_PRESCALER)     //!< Timer Delay for BT_RESET_PIN Detection. */
#define TX_TIMER_DELAY                  APP_TIMER_TICKS(20, APP_TIMER_PRESCALER)     //!< Timer delay to periodically send packets */


/*original settings*/
//#define MIN_CONN_INTERVAL             MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Determines minimum connection interval in millisecond. */
//#define MAX_CONN_INTERVAL             MSEC_TO_UNITS(75, UNIT_1_25_MS)             /**< Determines maximum connection interval in millisecond. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(40, UNIT_1_25_MS)             /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY                   0                                           /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */

#define FIRST_CONN_PARAMS_UPDATE_DELAY      APP_TIMER_TICKS(5000, APP_TIMER_PRESCALER)  /**< 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, APP_TIMER_PRESCALER) /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT        3


#define APP_GPIOTE_MAX_USERS            1                                           /**< Maximum number of users of the GPIOTE handler. */
#define BUTTON_DETECTION_DELAY          APP_TIMER_TICKS(50, APP_TIMER_PRESCALER)    /**< Delay from a GPIOTE event until a button is reported as pushed (in number of timer ticks). */

#define INITIAL_LLS_ALERT_LEVEL         BLE_CHAR_ALERT_LEVEL_NO_ALERT               /**< Initial value for the Alert Level characteristic in the Link Loss service. */


#define UART_TEST_MODE                  0
#if(UART_TEST_MODE)
static ble_uuid_t                       m_adv_uuids[] = {{BLE_UUID_NUS_SERVICE, 0x02}};  /**< Universally unique service identifier. */
#define SEC_PARAM_BOND                  0                                           /**< Perform bonding. */
#define SEC_PARAM_MITM                  0                                           /**< Man In The Middle protection not required. */
#else
#define SEC_PARAM_BOND                  1                                           /**< Perform bonding. */
#define SEC_PARAM_MITM                  1                                           /**< Man In The Middle protection not required. */
#endif


#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_DISPLAY_ONLY                /**< No I/O capabilities. */
//#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 PASSKEY_TXT                     "Passkey:"                                  /**< Message to be displayed together with the pass-key. */
#define PASSKEY_TXT_LENGTH              8                                           /**< Length of message to be displayed together with the pass-key. */
#define PASSKEY_LENGTH                  6                                           /**< Length of pass-key received by the stack for display. */

#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_TIMEOUT            30                                          //!< The duration of the fast advertising period (in seconds). */
#define APP_ADV_SLOW_TIMEOUT            180                                         //!< The duration of the slow advertising period (in seconds). */

#define UART_TX_BUF_SIZE                128                                         /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE                128                                         /**< UART RX buffer size. */

#define MAX_COMM_PACKET                 40
#define NRF_RX_MCU_TX_PIN               20
#define NRF_TX_MCU_RX_PIN               19

#define UART_STORAGE_SIZE               1024                                        /**< UART RX buffer size. */
#define UART_STORAGE_LEN                (UART_STORAGE_SIZE - 1)
#define TX_COMPLETE_TIMEOUT             200

#define QUEUE_LENGTH()  ((g_data_pck.g_tail >= g_data_pck.g_head) ? g_data_pck.g_tail - g_data_pck.g_head : UART_STORAGE_SIZE - g_data_pck.g_head + g_data_pck.g_tail)
#define QUEUE_FREE() ((g_data_pck.g_tail >= g_data_pck.g_head) ? UART_STORAGE_LEN - g_data_pck.g_tail + g_data_pck.g_head : g_data_pck.g_head - g_data_pck.g_tail - 1)

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

#define START_OF_PACKET                 0x49                                        // Start of packet
#define END_OF_PACKET                   0x42                                        // End of packet

#define TYPE_PASSKEY                    0x40
#define STATIC_PASSKEY                  "FFFFFF"

//static pm_peer_id_t                     m_peer_id;                                  //!< Device reference handle to the current bonded central. */
static uint16_t                         m_conn_handle = BLE_CONN_HANDLE_INVALID;    /**< Handle of the current connection. */
static ble_nus_t                        m_nus;                                      /**< Structure to identify the Nordic UART Service. */
static ble_lls_t                        m_lls;                                      /**< Structure used to identify the Link Loss service. */


APP_TIMER_DEF(m_sec_req_timer_id);                                                  //!< Security request timer. The timer lets us start pairing request if one does not arrive from the Central. */
APP_TIMER_DEF(m_sys_timer_id);                                                      //!< System user timer. The timer checks the bond erase pin to delete the bond data. */
APP_TIMER_DEF(m_tx_timer_id);                                                       //!< Security request timer. The timer checks the tx buffer to send packets using nus */
//APP_TIMER_DEF(m_mcu_rsp_timer_id);

static ble_opt_t  m_static_pin_option;
uint8_t passkey[] = STATIC_PASSKEY;
char bellopasskey[PASSKEY_LENGTH];
uint8_t  prev_bond;

const nrf_drv_uart_t  drv_uart_t = NRF_DRV_UART_INSTANCE(0);
pm_peer_id_t  m_peer_to_be_deleted = PM_PEER_ID_INVALID;

//static uint8_t  uartRxData[MAX_COMM_PACKET] = {0, };
static uint8_t  uartTxData[MAX_COMM_PACKET] = {0, };



typedef struct _DataPacket
{
  uint16_t  g_head ;
  uint16_t  g_peek ;
  uint16_t  g_tail ;
  uint16_t  g_pre_head ;
  uint16_t  g_pre_peek ;
  uint16_t  g_pre_tail ;
  uint8_t   g_buffer[UART_STORAGE_SIZE];
} DataPacket;
static DataPacket  g_data_pck;


static void advertising_start(void);
static void on_lls_evt(ble_lls_t * p_lls, ble_lls_evt_t * p_evt);
static uint16_t peekBuffer(uint8_t *p_data);






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





/**@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)
{
    ret_code_t err_code;

    //NRF_LOG_INFO("Peer evt : %d \r\n", p_evt->evt_id);

    switch (p_evt->evt_id)
    {
        case PM_EVT_BONDED_PEER_CONNECTED:
        {
            prev_bond = 1;
            NRF_LOG_INFO("Connected to a previously bonded device.\r\n");
        } break;

        case PM_EVT_CONN_SEC_SUCCEEDED:
        {
            pm_conn_sec_status_t conn_sec_status;

            // Check if the link is authenticated (meaning at least MITM).
            err_code = pm_conn_sec_status_get(p_evt->conn_handle, &conn_sec_status);
            APP_ERROR_CHECK(err_code);

            if (conn_sec_status.mitm_protected)
            {
                NRF_LOG_INFO("Link secured. Role: %d. conn_handle: %d, Procedure: %d\r\n",
                             ble_conn_state_role(p_evt->conn_handle),
                             p_evt->conn_handle,
                             p_evt->params.conn_sec_succeeded.procedure);
            }
            else
            {
                // The peer did not use MITM, disconnect.
                NRF_LOG_INFO("Collector did not use MITM, disconnecting\r\n");
                err_code = pm_peer_id_get(m_conn_handle, &m_peer_to_be_deleted);
                APP_ERROR_CHECK(err_code);
                err_code = sd_ble_gap_disconnect(m_conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                APP_ERROR_CHECK(err_code);
            }
        } break;

        case PM_EVT_CONN_SEC_FAILED:
        {
            NRF_LOG_INFO("Failed to secure connection. Disconnecting.\r\n");
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            err_code = sd_ble_gap_disconnect(p_evt->conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);

            /* Often, when securing fails, it shouldn't be restarted, for security reasons.
             * Other times, it can be restarted directly.
             * Sometimes it can be restarted, but only after changing some Security Parameters.
             * Sometimes, it cannot be restarted until the link is disconnected and reconnected.
             * Sometimes it is impossible, to secure the link, or the peer device does not support it.
             * How to handle this error is highly application dependent. */
        } break;

        case PM_EVT_CONN_SEC_CONFIG_REQ:
        {
            // Reject pairing request from an already bonded peer.
            pm_conn_sec_config_t conn_sec_config = {.allow_repairing = false};
            pm_conn_sec_config_reply(p_evt->conn_handle, &conn_sec_config);
        } break;

        case PM_EVT_STORAGE_FULL:
        {
            // Run garbage collection on the flash.
            err_code = fds_gc();
            if (err_code == FDS_ERR_BUSY || err_code == FDS_ERR_NO_SPACE_IN_QUEUES)
            {
                // Retry.
            }
            else
            {
                APP_ERROR_CHECK(err_code);
            }
        } break;

        case PM_EVT_PEERS_DELETE_SUCCEEDED:
        {
            advertising_start();
        } break;

        case PM_EVT_LOCAL_DB_CACHE_APPLY_FAILED:
        {
            // The local database has likely changed, send service changed indications.
            pm_local_database_has_changed();
        } break;

        case PM_EVT_PEER_DATA_UPDATE_FAILED:
        {
            // Assert.
            APP_ERROR_CHECK(p_evt->params.peer_data_update_failed.error);
        } break;

        case PM_EVT_PEER_DELETE_FAILED:
        {
            // Assert.
            APP_ERROR_CHECK(p_evt->params.peer_delete_failed.error);
        } break;

        case PM_EVT_PEERS_DELETE_FAILED:
        {
            // Assert.
            APP_ERROR_CHECK(p_evt->params.peers_delete_failed_evt.error);
        } break;

        case PM_EVT_ERROR_UNEXPECTED:
        {
            // Assert.
            APP_ERROR_CHECK(p_evt->params.error_unexpected.error);
        } break;

        case PM_EVT_CONN_SEC_START:
        case PM_EVT_PEER_DELETE_SUCCEEDED:
        case PM_EVT_LOCAL_DB_CACHE_APPLIED:
        case PM_EVT_SERVICE_CHANGED_IND_SENT:
        case PM_EVT_SERVICE_CHANGED_IND_CONFIRMED:
        default:
            break;
    }
}





/**@brief Function for handling the Security Request timer timeout.
 *
 * @details This function will be called each time the Security Request 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 sec_req_timeout_handler(void * p_context)
{
    uint32_t                err_code;
    pm_conn_sec_status_t    status;


        if (m_conn_handle != BLE_CONN_HANDLE_INVALID)
    {
        // Initiate bonding.
        err_code = pm_conn_sec_status_get(m_conn_handle, &status);
        APP_ERROR_CHECK(err_code);

        if(!status.encrypted){
            NRF_LOG_INFO("Start encryption\r\n");
            err_code = pm_conn_secure(m_conn_handle, false);
            if (err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
        }
    }
}





/**@brief Function for handling the Security Request timer timeout.
 *
 */
/*
static void mcu_rsp_timeout_handler(void * p_context)
{
}
*/










/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module.
 */
static void timers_init(void)
{
    uint32_t err_code;

    // Initialize timer module, making it use the scheduler.
    APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);

    // Create Security Request timer.
    err_code = app_timer_create(&m_sec_req_timer_id,
                                APP_TIMER_MODE_SINGLE_SHOT,
                                sec_req_timeout_handler);
    APP_ERROR_CHECK(err_code);
}





/**@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 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)
{
    uint32_t                err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

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

    err_code = sd_ble_gap_appearance_set(BLE_APPEARANCE_UNKNOWN);
    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 the Signals alert event from Immediate Alert or Link Loss services.
 *
 * @param[in] alert_level  Requested alert level.
 */
static void alert_signal(uint8_t alert_level)
{
    uint32_t err_code;

    switch (alert_level)
    {
        case BLE_CHAR_ALERT_LEVEL_NO_ALERT:
            NRF_LOG_INFO("No Alert.\r\n");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_OFF);
            APP_ERROR_CHECK(err_code);
            break; // BLE_CHAR_ALERT_LEVEL_NO_ALERT

        case BLE_CHAR_ALERT_LEVEL_MILD_ALERT:
            NRF_LOG_INFO("Mild Alert.\r\n");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_0);
            APP_ERROR_CHECK(err_code);
            break; // BLE_CHAR_ALERT_LEVEL_MILD_ALERT

        case BLE_CHAR_ALERT_LEVEL_HIGH_ALERT:
            NRF_LOG_INFO("HIGH Alert.\r\n");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_3);
            APP_ERROR_CHECK(err_code);
            break; // BLE_CHAR_ALERT_LEVEL_HIGH_ALERT

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





/**@brief Function for handling Link Loss events.
 *
 * @details This function will be called for all Link Loss events which are passed to the
 *          application.
 *
 * @param[in] p_lls  Link Loss structure.
 * @param[in] p_evt  Event received from the Link Loss service.
 */
static void on_lls_evt(ble_lls_t * p_lls, ble_lls_evt_t * p_evt)
{
    switch (p_evt->evt_type)
    {
        case BLE_LLS_EVT_LINK_LOSS_ALERT:
            alert_signal(p_evt->params.alert_level);
            break; // BLE_LLS_EVT_LINK_LOSS_ALERT

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






 /**@brief Function for initializing the Link Loss Service.
 */
static void lls_init(void)
{
    uint32_t       err_code;
    ble_lls_init_t lls_init_obj;

    // Initialize Link Loss Service
    memset(&lls_init_obj, 0, sizeof(lls_init_obj));

    lls_init_obj.evt_handler         = on_lls_evt;
    lls_init_obj.error_handler       = service_error_handler;
    lls_init_obj.initial_alert_level = INITIAL_LLS_ALERT_LEVEL;

    BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM(&lls_init_obj.lls_attr_md.read_perm);
    BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM(&lls_init_obj.lls_attr_md.write_perm);

    err_code = ble_lls_init(&m_lls, &lls_init_obj);
    APP_ERROR_CHECK(err_code);
}





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





/**@brief Function for handling the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module that
 *          are passed to the application.
 *
 * @note All this function does is to disconnect. This could have been done by simply
 *       setting the disconnect_on_fail config parameter, but instead we use the event
 *       handler mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
{
    uint32_t err_code;

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





/**@brief Function for handling 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)
{
    uint32_t               err_code;
    ble_conn_params_init_t cp_init;

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

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

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






/**@brief Function for 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;
    switch (event)
    {
        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();
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
            }
            break;
        default:
            break;
    }
}





/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    uint32_t ret;
    ret = ble_advertising_start(BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(ret);
}





/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    uint32_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            NRF_LOG_INFO("Fast advertising\r\n");
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_ADV_EVT_SLOW:
            NRF_LOG_INFO("Slow advertising\r\n");
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING_SLOW);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_ADV_EVT_IDLE:
            //sleep_mode_enter();
            break;
        default:
            break;
    }
}






/**@brief Function for handling the Application's BLE stack events.
 *
 * @param[in] p_ble_evt  Bluetooth stack event.
 */
static void on_ble_evt(ble_evt_t * p_ble_evt)
{
    uint32_t err_code = NRF_SUCCESS;

    /*NRF_LOG_INFO("BLE evt : %d %d %d \r\n"                       ,\
            p_ble_evt->header.evt_id                                ,\
            p_ble_evt->evt.gap_evt.params.auth_status.auth_status   ,\
            p_ble_evt->evt.gap_evt.params.auth_status.bonded        );*/

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_EVT_TX_COMPLETE:
            break;

        case BLE_GAP_EVT_SEC_INFO_REQUEST:
            break;

        case BLE_GAP_EVT_AUTH_STATUS:
            if(p_ble_evt->evt.gap_evt.params.auth_status.auth_status == BLE_GAP_SEC_STATUS_SUCCESS){
                nrf_gpio_pin_write(BT_CONN_PIN, GPIO_PIN_HIGH);
                NRF_LOG_INFO("CONN_PIN_HIGH.\r\n");

            }else{
                err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gap_evt.conn_handle,
                                                 BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }else{
                    NRF_LOG_INFO("FATAL ERROR !\r\n");
                }
            }
            break;
        case BLE_GAP_EVT_CONN_SEC_UPDATE:
            if(prev_bond || p_ble_evt->evt.gap_evt.params.auth_status.bonded){
                    prev_bond = 0;
                    nrf_gpio_pin_write(BT_CONN_PIN, GPIO_PIN_HIGH);
                    NRF_LOG_INFO("CONN_PIN_HIGH.\r\n");
            }

            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.\r\n");
            prev_bond = 0;
            nrf_gpio_pin_write(BT_CONN_PIN, GPIO_PIN_LOW);
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            /*check if the last connected peer had not used MITM, if so, delete its bond information*/
            if (m_peer_to_be_deleted != PM_PEER_ID_INVALID)
            {
                ret_code_t ret_val = pm_peer_delete(m_peer_to_be_deleted);
                APP_ERROR_CHECK(ret_val);
                NRF_LOG_INFO("Collector's bond deleted\r\n");
                m_peer_to_be_deleted = PM_PEER_ID_INVALID;
            }
            break; // BLE_GAP_EVT_DISCONNECTED

        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected\r\n");
            prev_bond = 0;
            m_peer_to_be_deleted = PM_PEER_ID_INVALID;

            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;

            uint8_t p_buff[4];
            err_code = nrf_drv_rng_rand(p_buff, 4);
            APP_ERROR_CHECK(err_code);

            for(uint8_t i=0; i<4; i++){
                passkey[i+2] = p_buff[i] % 9 + 48;
            }
            m_static_pin_option.gap_opt.passkey.p_passkey = &passkey[0];

            err_code =  sd_ble_opt_set(BLE_GAP_OPT_PASSKEY, &m_static_pin_option);
            APP_ERROR_CHECK(err_code);

            err_code = app_timer_start(m_sec_req_timer_id, SECURITY_REQUEST_DELAY, NULL);
            APP_ERROR_CHECK(err_code);
            break; // BLE_GAP_EVT_CONNECTED

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_INFO("GATT Client Timeout.\r\n");
            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; // BLE_GATTC_EVT_TIMEOUT

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_INFO("GATT Server Timeout.\r\n");
            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; // BLE_GATTS_EVT_TIMEOUT

        case BLE_GAP_EVT_PASSKEY_DISPLAY:
        {
            char passkey[PASSKEY_LENGTH + 1];
            memcpy(passkey, p_ble_evt->evt.gap_evt.params.passkey_display.passkey, PASSKEY_LENGTH);
            passkey[PASSKEY_LENGTH] = 0;
            // Don't send delayed Security Request if security procedure is already in progress.
            err_code = app_timer_stop(m_sec_req_timer_id);
            APP_ERROR_CHECK(err_code);

            memcpy(bellopasskey, passkey, PASSKEY_LENGTH);

            //err_code = app_timer_start(m_mcu_rsp_timer_id, MCU_RESPONSE_DELAY, NULL);
            //APP_ERROR_CHECK(err_code);

            NRF_LOG_INFO("Passkey: %s\r\n",nrf_log_push(passkey));
        } break; // BLE_GAP_EVT_PASSKEY_DISPLAY


        case BLE_EVT_USER_MEM_REQUEST:
            err_code = sd_ble_user_mem_reply(p_ble_evt->evt.gattc_evt.conn_handle, NULL);
            APP_ERROR_CHECK(err_code);
            break; // BLE_EVT_USER_MEM_REQUEST

        case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
            /*err_code = sd_ble_gap_sec_params_reply(m_conn_handle,
                                                   BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP,
                                                   NULL,
                                                   NULL);
            APP_ERROR_CHECK(err_code);*/
            break; // BLE_GAP_EVT_SEC_PARAMS_REQUEST

        case BLE_GATTS_EVT_SYS_ATTR_MISSING:
            // No system attributes have been stored.
            err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
            APP_ERROR_CHECK(err_code);
            break; // BLE_GATTS_EVT_SYS_ATTR_MISSING

       case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST:
        {
            ble_gatts_evt_rw_authorize_request_t  req;
            ble_gatts_rw_authorize_reply_params_t auth_reply;

            req = p_ble_evt->evt.gatts_evt.params.authorize_request;

            if (req.type != BLE_GATTS_AUTHORIZE_TYPE_INVALID)
            {
                if ((req.request.write.op == BLE_GATTS_OP_PREP_WRITE_REQ)     ||
                    (req.request.write.op == BLE_GATTS_OP_EXEC_WRITE_REQ_NOW) ||
                    (req.request.write.op == BLE_GATTS_OP_EXEC_WRITE_REQ_CANCEL))
                {
                    if (req.type == BLE_GATTS_AUTHORIZE_TYPE_WRITE)
                    {
                        auth_reply.type = BLE_GATTS_AUTHORIZE_TYPE_WRITE;
                    }
                    else
                    {
                        auth_reply.type = BLE_GATTS_AUTHORIZE_TYPE_READ;
                    }
                    auth_reply.params.write.gatt_status = APP_FEATURE_NOT_SUPPORTED;
                    err_code = sd_ble_gatts_rw_authorize_reply(p_ble_evt->evt.gatts_evt.conn_handle,
                                                               &auth_reply);
                    APP_ERROR_CHECK(err_code);
                }
            }
        } break; // BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST

#if (NRF_SD_BLE_API_VERSION == 3)
        case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST:
            err_code = sd_ble_gatts_exchange_mtu_reply(p_ble_evt->evt.gatts_evt.conn_handle,
                                                       NRF_BLE_MAX_MTU_SIZE);
            APP_ERROR_CHECK(err_code);
            break; // BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST
#endif

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





/**@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 initializing the Advertising functionality.
 *
 * @details Encodes the required advertising data and passes it to the stack.
 *          Also builds a structure to be passed to the stack when starting advertising.
 */
static void advertising_init(void)
{
    uint32_t      err_code;
    ble_advdata_t advdata;
    ble_adv_modes_config_t options;

    // Build and set advertising data
    memset(&advdata, 0, sizeof(advdata));

    advdata.name_type          = BLE_ADVDATA_FULL_NAME;
    advdata.include_appearance = true;
    advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;

    options.ble_adv_whitelist_enabled      = false;
    options.ble_adv_directed_enabled       = false;
    options.ble_adv_directed_slow_enabled  = false;
    options.ble_adv_directed_slow_interval = 0;
    options.ble_adv_directed_slow_timeout  = 0;
    options.ble_adv_fast_enabled           = true;
    options.ble_adv_fast_interval          = APP_ADV_FAST_INTERVAL;
    options.ble_adv_fast_timeout           = APP_ADV_FAST_TIMEOUT;
    options.ble_adv_slow_enabled           = true;
    options.ble_adv_slow_interval          = APP_ADV_SLOW_INTERVAL;
    //options.ble_adv_slow_timeout           = APP_ADV_SLOW_TIMEOUT;

#if(UART_TEST_MODE)
    ble_advdata_t scanrsp;
    memset(&scanrsp, 0, sizeof(scanrsp));
    scanrsp.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    scanrsp.uuids_complete.p_uuids  = m_adv_uuids;
    err_code = ble_advertising_init(&advdata, &scanrsp, &options, on_adv_evt, NULL);
#else
    err_code = ble_advertising_init(&advdata, NULL, &options, on_adv_evt, NULL);
#endif

    APP_ERROR_CHECK(err_code);
}





/**@brief Function for dispatching a BLE stack event to all modules with a BLE stack event handler.
 *
 * @details This function is called from the scheduler in the main loop after a BLE stack
 *          event has been received.
 *
 * @param[in] p_ble_evt  Bluetooth stack event.
 */
static void ble_evt_dispatch(ble_evt_t * p_ble_evt)
{
    ble_conn_state_on_ble_evt(p_ble_evt);
    pm_on_ble_evt(p_ble_evt);
    ble_lls_on_ble_evt(&m_lls, p_ble_evt);
    ble_nus_on_ble_evt(&m_nus, p_ble_evt);
    ble_conn_params_on_ble_evt(p_ble_evt);
    on_ble_evt(p_ble_evt);
    ble_advertising_on_ble_evt(p_ble_evt);
}





/**@brief Function for dispatching a system event to interested modules.
 *
 * @details This function is called from the System event interrupt handler after a system
 *          event has been received.
 *
 * @param[in] sys_evt  System stack event.
 */
static void sys_evt_dispatch(uint32_t sys_evt)
{
    // Dispatch the system event to the fstorage module, where it will be
    // dispatched to the Flash Data Storage (FDS) module.
    fs_sys_event_handler(sys_evt);

    // Dispatch to the Advertising module last, since it will check if there are any
    // pending flash operations in fstorage. Let fstorage process system events first,
    // so that it can report correctly to the Advertising module.
    ble_advertising_on_sys_evt(sys_evt);
}





/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void)
{
    uint32_t err_code;

    nrf_clock_lf_cfg_t clock_lf_cfg = NRF_CLOCK_LFCLKSRC;

    // Initialize the SoftDevice handler module.
    SOFTDEVICE_HANDLER_INIT(&clock_lf_cfg, NULL);

    ble_enable_params_t ble_enable_params;
    err_code = softdevice_enable_get_default_config(CENTRAL_LINK_COUNT,
                                                    PERIPHERAL_LINK_COUNT,
                                                    &ble_enable_params);
    APP_ERROR_CHECK(err_code);

    //Check the ram settings against the used number of links
    CHECK_RAM_START_ADDR(CENTRAL_LINK_COUNT, PERIPHERAL_LINK_COUNT);

    // Enable BLE stack.
#if (NRF_SD_BLE_API_VERSION == 3)
    ble_enable_params.gatt_enable_params.att_mtu = NRF_BLE_MAX_MTU_SIZE;
#endif
    err_code = softdevice_enable(&ble_enable_params);
    APP_ERROR_CHECK(err_code);

    // Subscribe for BLE events.
    err_code = softdevice_ble_evt_handler_set(ble_evt_dispatch);
    APP_ERROR_CHECK(err_code);

    // Register with the SoftDevice handler module for BLE events.
    err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
    APP_ERROR_CHECK(err_code);

}





/**@brief Function for the Peer Manager initialization.
 *
 * @param[in] erase_bonds  Indicates whether bonding information should be cleared from
 *                         persistent storage during initialization of the Peer Manager.
 */
static void peer_manager_init(bool erase_bonds)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);

    if (erase_bonds)
    {
        err_code = pm_peers_delete();
        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 the Power Manager.
 */
static void power_manage(void)
{
    uint32_t err_code = sd_app_evt_wait();
    APP_ERROR_CHECK(err_code);
}











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

    uint32_t err_code = bsp_init(BSP_INIT_LED | BSP_INIT_BUTTONS,
                                 APP_TIMER_TICKS(100, APP_TIMER_PRESCALER),
                                 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 gpio.
 */
void gpio_init(void){
    nrf_drv_gpiote_init();

    nrf_gpio_pin_dir_set(BT_RESET_PIN, NRF_GPIO_PIN_DIR_INPUT );

    nrf_gpio_pin_dir_set(BT_CONN_PIN, NRF_GPIO_PIN_DIR_OUTPUT );
    nrf_gpio_pin_write(BT_CONN_PIN, GPIO_PIN_LOW);
    prev_bond = 0;
}





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

    // Initialize.
    gpio_init();

    err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    timers_init();
    buttons_leds_init(&erase_bonds);
    ble_stack_init();

#if(SEC_PARAM_BOND)
    //peer_manager_init(erase_bonds);
    peer_manager_init(false);
#endif

    if (erase_bonds == true)
    {
        NRF_LOG_INFO("Bonds erased\r\n");
    }

    gap_params_init();
    services_init();
    advertising_init();
    conn_params_init();

    // Start execution.
    NRF_LOG_INFO("BLE FW VERSION ... %s \r\n", nrf_log_push(FW_VERSION));

    advertising_start();

    // Enter main loop.
    for (;;)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            power_manage();
        }
    }
}


/**
 * @}
 */

My main.c