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Bluetooth disconnects when notification enabled

Hi,

I'm using SDK 15.2. The bluetooth disconnects when I enable notifications on nrfConnect. This happens only if I increase the number of bytes to be sent. I'm writing a code for custom gatt. The references I used were - 

https://github.com/maidenone/custom_ble_service_example

https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-characteristics-a-beginners-tutorial

My code files - 

#include "sdk_common.h"
#include "ble_srv_common.h"
#include "ble_cus.h"
#include <string.h>
#include "nrf_gpio.h"
#include "boards.h"
#include "nrf_log.h"

/**@brief Function for handling the Connect event.
 * @param[in]   p_cus       Custom Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack. */
static void on_connect(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
{
    p_cus->conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    ble_cus_evt_t evt;
    evt.evt_type = BLE_CUS_EVT_CONNECTED;
    p_cus->evt_handler(p_cus, &evt);
}

/**@brief Function for handling the Disconnect event.
 * @param[in]   p_cus       Custom Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack. */
static void on_disconnect(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
{
    UNUSED_PARAMETER(p_ble_evt);
    p_cus->conn_handle = BLE_CONN_HANDLE_INVALID;
    ble_cus_evt_t evt;
    evt.evt_type = BLE_CUS_EVT_DISCONNECTED;
    p_cus->evt_handler(p_cus, &evt);
}

/**@brief Function for handling the Write event.
 * @param[in]   p_cus       Custom Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack. */
static void on_write(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
{
	ble_gatts_evt_write_t const * p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;
    // Custom Value Characteristic Written to.
    if (p_evt_write->handle == p_cus->custom_value_handles.value_handle)
    {
        nrf_gpio_pin_toggle(LED_4);
        NRF_LOG_INFO("GOT WRITE ON: %d",*p_evt_write->data);
        if(*p_evt_write->data == 0x01)
        {
            nrf_gpio_pin_clear(LED_3);
        }
        else if(*p_evt_write->data == 0x02)
        {
            nrf_gpio_pin_set(LED_3);
        }
        else
        {
          //Do nothing
        }
    }
    // Check if the Custom value CCCD is written to and that the value is the appropriate length, i.e 2 bytes.
    if ((p_evt_write->handle == p_cus->custom_value_handles.cccd_handle) && (p_evt_write->len == 2))
    {
        // CCCD written, call application event handler
        if (p_cus->evt_handler != NULL)
        {
            ble_cus_evt_t evt;
            if (ble_srv_is_notification_enabled(p_evt_write->data))
            {
                evt.evt_type = BLE_CUS_EVT_NOTIFICATION_ENABLED;
            }
            else
            {
                evt.evt_type = BLE_CUS_EVT_NOTIFICATION_DISABLED;
            }
            // Call the application event handler.
            p_cus->evt_handler(p_cus, &evt);
        }
    }
}

void ble_cus_on_ble_evt( ble_evt_t const * p_ble_evt, void * p_context)
{
    ble_cus_t * p_cus = (ble_cus_t *) p_context;
    NRF_LOG_INFO("BLE event received. Event type = %d\r\n", p_ble_evt->header.evt_id);
    if (p_cus == NULL || p_ble_evt == NULL)
    {
        return;
    }
    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            on_connect(p_cus, p_ble_evt);
            break;
        case BLE_GAP_EVT_DISCONNECTED:
            on_disconnect(p_cus, p_ble_evt);
            break;
        case BLE_GATTS_EVT_WRITE:
            on_write(p_cus, p_ble_evt);
            break;
/* Handling this event is not necessary
        case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST:
            NRF_LOG_INFO("EXCHANGE_MTU_REQUEST event received.\r\n");
            break;*/
        default:
            // No implementation needed.
            break;
    }
}

/**@brief Function for adding the Custom Value characteristic.
 * @param[in]   p_cus        Custom Service structure.
 * @param[in]   p_cus_init   Information needed to initialize the service.
 * @return      NRF_SUCCESS on success, otherwise an error code. */
static uint32_t custom_value_char_add(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
{
    uint32_t            err_code;
    ble_gatts_char_md_t char_md;
    ble_gatts_attr_md_t cccd_md;
    ble_gatts_attr_t    attr_char_value;
    ble_uuid_t          ble_uuid;
    ble_gatts_attr_md_t attr_md;

    // Add Custom Value characteristic
    memset(&cccd_md, 0, sizeof(cccd_md));

    //  Read  operation on cccd should be possible without authentication.
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);

    cccd_md.write_perm = p_cus_init->custom_value_char_attr_md.cccd_write_perm;
    cccd_md.vloc       = BLE_GATTS_VLOC_STACK;

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

    char_md.char_props.read   = 1;
    char_md.char_props.write  = 1;
    char_md.char_props.notify = 1;
    char_md.p_char_user_desc  = NULL;
    char_md.p_char_pf         = NULL;
    char_md.p_user_desc_md    = NULL;
    char_md.p_cccd_md         = &cccd_md;
    char_md.p_sccd_md         = NULL;

    ble_uuid.type = p_cus->uuid_type;
    ble_uuid.uuid = CUSTOM_VALUE_CHAR_UUID;

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

    attr_md.read_perm  = p_cus_init->custom_value_char_attr_md.read_perm;
    attr_md.write_perm = p_cus_init->custom_value_char_attr_md.write_perm;
    attr_md.vloc       = BLE_GATTS_VLOC_STACK;
    attr_md.rd_auth    = 0;
    attr_md.wr_auth    = 0;
    attr_md.vlen       = 0;

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

    attr_char_value.p_uuid    = &ble_uuid;
    attr_char_value.p_attr_md = &attr_md;
    attr_char_value.init_len  = sizeof(uint8_t);
    attr_char_value.init_offs = 0;
    attr_char_value.max_len   = sizeof(uint8_t);

    err_code = sd_ble_gatts_characteristic_add(p_cus->service_handle, &char_md, &attr_char_value, &p_cus->custom_value_handles);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }

    return NRF_SUCCESS;
}

uint32_t ble_cus_init(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
{
    if (p_cus == NULL || p_cus_init == NULL)
    {
        return NRF_ERROR_NULL;
    }
    uint32_t   err_code;
    ble_uuid_t ble_uuid;
    // Initialize service structure
    p_cus->evt_handler               = p_cus_init->evt_handler;
    p_cus->conn_handle               = BLE_CONN_HANDLE_INVALID;
    // Add Custom Service UUID
    ble_uuid128_t base_uuid = {CUSTOM_SERVICE_UUID_BASE};
    err_code =  sd_ble_uuid_vs_add(&base_uuid, &p_cus->uuid_type);
    VERIFY_SUCCESS(err_code);
    ble_uuid.type = p_cus->uuid_type;
    ble_uuid.uuid = CUSTOM_SERVICE_UUID;
    // Add the Custom Service
    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_cus->service_handle);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }
    // Add Custom Value characteristic
    return custom_value_char_add(p_cus, p_cus_init);
}

uint32_t ble_cus_custom_value_update(ble_cus_t * p_cus, uint8_t custom_value[20])	/*NEW CHANGE*/
{
    NRF_LOG_INFO("In ble_cus_custom_value_update. \r\n");
    if (p_cus == NULL)
    {
        return NRF_ERROR_NULL;
    }
    uint32_t err_code = NRF_SUCCESS;
    ble_gatts_value_t gatts_value;
    // Initialize value struct.
    memset(&gatts_value, 0, sizeof(gatts_value));
    gatts_value.len     = 20*sizeof(uint8_t);	/*NEW CHANGE*/
    gatts_value.offset  = 0;
    gatts_value.p_value = &custom_value[0];
    // Update database.
    err_code = sd_ble_gatts_value_set(p_cus->conn_handle, p_cus->custom_value_handles.value_handle, &gatts_value);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }
    // Send value if connected and notifying.
    if ((p_cus->conn_handle != BLE_CONN_HANDLE_INVALID))
    {
        ble_gatts_hvx_params_t hvx_params;
        memset(&hvx_params, 0, sizeof(hvx_params));
        hvx_params.handle = p_cus->custom_value_handles.value_handle;
        hvx_params.type   = BLE_GATT_HVX_NOTIFICATION;
        hvx_params.offset = gatts_value.offset;
        hvx_params.p_len  = &gatts_value.len;
        hvx_params.p_data = gatts_value.p_value;
        err_code = sd_ble_gatts_hvx(p_cus->conn_handle, &hvx_params);
        NRF_LOG_INFO("sd_ble_gatts_hvx result: %x. \r\n", err_code);
    }
    else
    {
        err_code = NRF_ERROR_INVALID_STATE;
        NRF_LOG_INFO("sd_ble_gatts_hvx result: NRF_ERROR_INVALID_STATE. \r\n");
    }
    return err_code;
}

ble_cus.h

/**
 * Copyright (c) 2014 - 2018, 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_template_main main.c
 * @{
 * @ingroup ble_sdk_app_template
 * @brief Template project main file.
 *
 * This file contains a template for creating a new application. It has the code necessary to wakeup
 * from button, advertise, get a connection restart advertising on disconnect and if no new
 * connection created go back to system-off mode.
 * It can easily be used as a starting point for creating a new application, the comments identified
 * with 'YOUR_JOB' indicates where and how you can customize.
 */

#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include "nordic_common.h"
#include "nrf.h"
#include "app_error.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_srv_common.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "app_timer.h"
#include "fds.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "bsp_btn_ble.h"
#include "sensorsim.h"
#include "ble_conn_state.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"

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

/*new*/
#include "ble_cus.h"

#define DEVICE_NAME                     "Forte"                       /**< 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 MIN_CONN_INTERVAL               MSEC_TO_UNITS(100, UNIT_1_25_MS)        /**< Minimum acceptable connection interval (0.1 seconds). */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(200, UNIT_1_25_MS)        /**< Maximum acceptable connection interval (0.2 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. */

/*new*/
#define NOTIFICATION_INTERVAL           APP_TIMER_TICKS(100)

#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. */

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. */

/*new*/
BLE_CUS_DEF(m_cus);
APP_TIMER_DEF(m_notification_timer_id);

/*new*/
static uint8_t m_custom_value = 0;

static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID;                        /**< Handle of the current connection. */

/* YOUR_JOB: Declare all services structure your application is using
 *  BLE_XYZ_DEF(m_xyz);
 */

// YOUR_JOB: Use UUIDs for service(s) used in your application.
/*static ble_uuid_t m_adv_uuids[] =                                               /**< Universally unique service identifiers. */
/*{
    {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE}
};*/

/*new*/
ble_uuid_t m_adv_uuids[] = {{CUSTOM_SERVICE_UUID, BLE_UUID_TYPE_VENDOR_BEGIN }}; /**< Universally unique service identifiers. */

static void advertising_start(bool erase_bonds);

/**@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 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;
    //pm_handler_on_pm_evt(p_evt);
    //pm_handler_flash_clean(p_evt);
    switch (p_evt->evt_id)
    {
		case PM_EVT_BONDED_PEER_CONNECTED:
        {
            NRF_LOG_INFO("Connected to a previously bonded device.");
        } break;
		case PM_EVT_CONN_SEC_SUCCEEDED:
        {
            NRF_LOG_INFO("Connection secured: role: %d, conn_handle: 0x%x, procedure: %d.", ble_conn_state_role(p_evt->conn_handle),
                         p_evt->conn_handle, p_evt->params.conn_sec_succeeded.procedure);
        } break;
		case PM_EVT_CONN_SEC_FAILED:
        {
            /* 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_NO_SPACE_IN_QUEUES)
            {
                // Retry.
            }
            else
            {
                APP_ERROR_CHECK(err_code);
            }
        } break;
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            advertising_start(false);
            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_DATA_UPDATE_SUCCEEDED:
        case PM_EVT_PEER_DELETE_SUCCEEDED:
        case PM_EVT_LOCAL_DB_CACHE_APPLIED:
        case PM_EVT_LOCAL_DB_CACHE_APPLY_FAILED:
            // This can happen when the local DB has changed.
        case PM_EVT_SERVICE_CHANGED_IND_SENT:
        case PM_EVT_SERVICE_CHANGED_IND_CONFIRMED:
        default:
            break;
    }
}

/**@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 notification_timeout_handler(void * p_context)
{
    UNUSED_PARAMETER(p_context);
    ret_code_t err_code;

    // Increment the value of m_custom_value before nortifing it.
    m_custom_value++;

    err_code = ble_cus_custom_value_update(&m_cus, m_custom_value);
    APP_ERROR_CHECK(err_code);
}

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

    // Create timers.
    err_code = app_timer_create(&m_notification_timer_id, APP_TIMER_MODE_REPEATED, notification_timeout_handler);
    APP_ERROR_CHECK(err_code);
	
    /* YOUR_JOB: Create any timers to be used by the application.
                 Below is an example of how to create a timer.
                 For every new timer needed, increase the value of the macro APP_TIMER_MAX_TIMERS by
                 one.
       ret_code_t err_code;
       err_code = app_timer_create(&m_app_timer_id, APP_TIMER_MODE_REPEATED, timer_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);
    /* YOUR_JOB: Use an appearance value matching the application's use case.
       err_code = sd_ble_gap_appearance_set(BLE_APPEARANCE_);
       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 handling the YYY Service events.
 * YOUR_JOB implement a service handler function depending on the event the service you are using can generate
 *
 * @details This function will be called for all YY Service events which are passed to
 *          the application.
 *
 * @param[in]   p_yy_service   YY Service structure.
 * @param[in]   p_evt          Event received from the YY Service.
 *
 *
static void on_yys_evt(ble_yy_service_t     * p_yy_service,
                       ble_yy_service_evt_t * p_evt)
{
    switch (p_evt->evt_type)
    {
        case BLE_YY_NAME_EVT_WRITE:
            APPL_LOG("[APPL]: charact written with value %s. ", p_evt->params.char_xx.value.p_str);
            break;

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

/**@brief Function for handling the Custom Service Service events.
 * @details This function will be called for all Custom Service events which are passed to the application.
 * @param[in]   p_cus_service  Custom Service structure.
 * @param[in]   p_evt          Event received from the Custom Service. */
static void on_cus_evt(ble_cus_t     * p_cus_service, ble_cus_evt_t * p_evt)
{
    ret_code_t err_code;
    switch(p_evt->evt_type)
    {
        case BLE_CUS_EVT_NOTIFICATION_ENABLED:
             err_code = app_timer_start(m_notification_timer_id, NOTIFICATION_INTERVAL, NULL);
             APP_ERROR_CHECK(err_code);
             break;
        case BLE_CUS_EVT_NOTIFICATION_DISABLED:
            err_code = app_timer_stop(m_notification_timer_id);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_CUS_EVT_CONNECTED:
            break;
        case BLE_CUS_EVT_DISCONNECTED:
              break;
        default:
              // No implementation needed.
              break;
    }
}

/**@brief Function for initializing services that will be used by the application.
 */
static void services_init(void)
{
    ret_code_t         err_code;
    nrf_ble_qwr_init_t qwr_init = {0};
	ble_cus_init_t      cus_init = {0};/*new*/
    // 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 CUS Service init structure to zero.
    cus_init.evt_handler                = on_cus_evt;
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.cccd_write_perm);
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.read_perm);
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.write_perm);
    err_code = ble_cus_init(&m_cus, &cus_init);
    APP_ERROR_CHECK(err_code);
}

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

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

/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;
    memset(&cp_init, 0, sizeof(cp_init));
    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = 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 starting timers.
 */
static void application_timers_start(void)
{
    /* YOUR_JOB: Start your timers. below is an example of how to start a timer.
       ret_code_t err_code;
       err_code = app_timer_start(m_app_timer_id, TIMER_INTERVAL, NULL);
       APP_ERROR_CHECK(err_code); */
}

/**@brief Function for putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void)
{
    ret_code_t err_code;
    err_code = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);
    // Prepare wakeup buttons.
    err_code = bsp_btn_ble_sleep_mode_prepare();
    APP_ERROR_CHECK(err_code);
    // Go to system-off mode (this function will not return; wakeup will cause a reset).
    err_code = sd_power_system_off();
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    ret_code_t err_code;
    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            NRF_LOG_INFO("Fast advertising.");
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_ADV_EVT_IDLE:
            sleep_mode_enter();
            break;
        default:
            break;
    }
}

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

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");
            // LED indication will be changed when advertising starts.
            break;

        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_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 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 Peer Manager initialization.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t           err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);

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

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

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

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


/**@brief Clear 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 handling events from the BSP module.
 *
 * @param[in]   event   Event generated when button is pressed.
 */
static void bsp_event_handler(bsp_event_t event)
{
    ret_code_t err_code;

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

        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; // BSP_EVENT_DISCONNECT

        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; // BSP_EVENT_KEY_0

        default:
            break;
    }
}


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

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

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

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

    init.evt_handler = on_adv_evt;

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

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}

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

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

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

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


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

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


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


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

/**@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_DELETED_SUCEEDED event
    }
    else
    {
        ret_code_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
        APP_ERROR_CHECK(err_code);
    }
}

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

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

    // Start execution.
    NRF_LOG_INFO("Template example started.");
    application_timers_start();

    advertising_start(erase_bonds);

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


/**
 * @}
 */

sdk_config.h

Parents
  • Hello,

    Can you try to define DEBUG in your preprocessor defines, and monitor the log on the nRF? What does it say when you try to enable notifications?

    Best regards,

    Edvin

  • Its failing in ble_cus_custom_value_update() with fatal error.

  • did you define DEBUG in your preprocessor defines? If you are not sure how to do it, let me know what compiler/IDE you are using, and I can help you. Segger Embedded Studio? Keil? something else?

    When you define DEBUG it should tell you what the call to ble_cus_custom_value_update() returned, which is useful information, and not just that it returned != 0

  • Hi,

    The above error got fixed by referring to https://devzone.nordicsemi.com/f/nordic-q-a/34650/custom_ble_service_example---uint16_t-custom_value---nrf_error_data_size.

    But now I'm able to send only 20 bytes out of 29 bytes. 

    Changes I made - 

    In sdk_config.h -----------

    #define NRF_SDH_BLE_GAP_DATA_LENGTH 36

    #define NRF_SDH_BLE_GATT_MAX_MTU_SIZE 32

    BLE_GATT_ATT_MTU_DEFAULT = 32 define in ble_gatt.h

    changed the RAM settings

    static uint32_t custom_value_char_add(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
    {
        uint32_t            err_code;
        ble_gatts_char_md_t char_md;
        ble_gatts_attr_md_t cccd_md;
        ble_gatts_attr_t    attr_char_value;
        ble_uuid_t          ble_uuid;
        ble_gatts_attr_md_t attr_md;
    
        // Add Custom Value characteristic
        memset(&cccd_md, 0, sizeof(cccd_md));
    
        //  Read  operation on cccd should be possible without authentication.
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
    
        cccd_md.write_perm = p_cus_init->custom_value_char_attr_md.cccd_write_perm;
        cccd_md.vloc       = BLE_GATTS_VLOC_STACK;
    
        memset(&char_md, 0, sizeof(char_md));
    
        char_md.char_props.read   = 1;
        char_md.char_props.write  = 1;
        char_md.char_props.notify = 1;
        char_md.p_char_user_desc  = NULL;
        char_md.p_char_pf         = NULL;
        char_md.p_user_desc_md    = NULL;
        char_md.p_cccd_md         = &cccd_md;
        char_md.p_sccd_md         = NULL;
    
        ble_uuid.type = p_cus->uuid_type;
        ble_uuid.uuid = CUSTOM_VALUE_CHAR_UUID;
    
        memset(&attr_md, 0, sizeof(attr_md));
    
        attr_md.read_perm  = p_cus_init->custom_value_char_attr_md.read_perm;
        attr_md.write_perm = p_cus_init->custom_value_char_attr_md.write_perm;
        attr_md.vloc       = BLE_GATTS_VLOC_STACK;
        attr_md.rd_auth    = 0;
        attr_md.wr_auth    = 0;
        attr_md.vlen       = 0;
    
        memset(&attr_char_value, 0, sizeof(attr_char_value));
    
        attr_char_value.p_uuid    = &ble_uuid;
        attr_char_value.p_attr_md = &attr_md;
        attr_char_value.init_len  = 29*sizeof(uint8_t);
        attr_char_value.init_offs = 0;
        attr_char_value.max_len   = 29*sizeof(uint8_t);
    
        err_code = sd_ble_gatts_characteristic_add(p_cus->service_handle, &char_md, &attr_char_value, &p_cus->custom_value_handles);
        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
    
        return NRF_SUCCESS;
    }

    uint32_t ble_cus_custom_value_update(ble_cus_t * p_cus, uint8_t * custom_value)	/*NEW CHANGE*/
    {
        NRF_LOG_INFO("In ble_cus_custom_value_update. \r\n");
        if (p_cus == NULL)
        {
            return NRF_ERROR_NULL;
        }
        uint32_t err_code = NRF_SUCCESS;
        ble_gatts_value_t gatts_value;
        // Initialize value struct.
        memset(&gatts_value, 0, sizeof(gatts_value));
        gatts_value.len     = 29*sizeof(uint8_t);	/*NEW CHANGE*/
        gatts_value.offset  = 0;
        gatts_value.p_value = custom_value;
        // Update database.
        err_code = sd_ble_gatts_value_set(p_cus->conn_handle, p_cus->custom_value_handles.value_handle, &gatts_value);
        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
        // Send value if connected and notifying.
        if ((p_cus->conn_handle != BLE_CONN_HANDLE_INVALID))
        {
            ble_gatts_hvx_params_t hvx_params;
            memset(&hvx_params, 0, sizeof(hvx_params));
            hvx_params.handle = p_cus->custom_value_handles.value_handle;
            hvx_params.type   = BLE_GATT_HVX_NOTIFICATION;
            hvx_params.offset = gatts_value.offset;
            hvx_params.p_len  = &gatts_value.len;
            hvx_params.p_data = gatts_value.p_value;
            err_code = sd_ble_gatts_hvx(p_cus->conn_handle, &hvx_params);
            NRF_LOG_INFO("sd_ble_gatts_hvx result: %x. \r\n", err_code);
    		NRF_LOG_INFO("hvx_params.p_len: %x. \r\n", &hvx_params.p_len);
        }
        else
        {
            err_code = NRF_ERROR_INVALID_STATE;
            NRF_LOG_INFO("sd_ble_gatts_hvx result: NRF_ERROR_INVALID_STATE. \r\n");
        }
        return err_code;
    }

    Also how do I receive 20 bytes from host? Right now its just a byte.

    static void on_write(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
    {
    	ble_gatts_evt_write_t const * p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;
        // Custom Value Characteristic Written to.
        if (p_evt_write->handle == p_cus->custom_value_handles.value_handle)
        {
            nrf_gpio_pin_toggle(LED_4);
            NRF_LOG_INFO("GOT WRITE ON: %d",*p_evt_write->data);
            if(*p_evt_write->data == 0x01)
            {
                nrf_gpio_pin_clear(LED_3);
            }
            else if(*p_evt_write->data == 0x02)
            {
                nrf_gpio_pin_set(LED_3);
            }
            else
            {
              //Do nothing
            }
        }
        // Check if the Custom value CCCD is written to and that the value is the appropriate length, i.e 2 bytes.
        if ((p_evt_write->handle == p_cus->custom_value_handles.cccd_handle) && (p_evt_write->len == 2))
        {
            // CCCD written, call application event handler
            if (p_cus->evt_handler != NULL)
            {
                ble_cus_evt_t evt;
                if (ble_srv_is_notification_enabled(p_evt_write->data))
                {
                    evt.evt_type = BLE_CUS_EVT_NOTIFICATION_ENABLED;
                }
                else
                {
                    evt.evt_type = BLE_CUS_EVT_NOTIFICATION_DISABLED;
                }
                // Call the application event handler.
                p_cus->evt_handler(p_cus, &evt);
            }
        }
    }
    

    My files -

    #include "sdk_common.h"
    #include "ble_srv_common.h"
    #include "ble_cus.h"
    #include <string.h>
    #include "nrf_gpio.h"
    #include "boards.h"
    #include "nrf_log.h"
    
    /**@brief Function for handling the Connect event.
     * @param[in]   p_cus       Custom Service structure.
     * @param[in]   p_ble_evt   Event received from the BLE stack. */
    static void on_connect(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
    {
        p_cus->conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
        ble_cus_evt_t evt;
        evt.evt_type = BLE_CUS_EVT_CONNECTED;
        p_cus->evt_handler(p_cus, &evt);
    }
    
    /**@brief Function for handling the Disconnect event.
     * @param[in]   p_cus       Custom Service structure.
     * @param[in]   p_ble_evt   Event received from the BLE stack. */
    static void on_disconnect(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
    {
        UNUSED_PARAMETER(p_ble_evt);
        p_cus->conn_handle = BLE_CONN_HANDLE_INVALID;
        ble_cus_evt_t evt;
        evt.evt_type = BLE_CUS_EVT_DISCONNECTED;
        p_cus->evt_handler(p_cus, &evt);
    }
    
    /**@brief Function for handling the Write event.
     * @param[in]   p_cus       Custom Service structure.
     * @param[in]   p_ble_evt   Event received from the BLE stack. */
    static void on_write(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
    {
    	ble_gatts_evt_write_t const * p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;
        // Custom Value Characteristic Written to.
        if (p_evt_write->handle == p_cus->custom_value_handles.value_handle)
        {
            nrf_gpio_pin_toggle(LED_4);
            NRF_LOG_INFO("GOT WRITE ON: %d",*p_evt_write->data);
            if(*p_evt_write->data == 0x01)
            {
                nrf_gpio_pin_clear(LED_3);
            }
            else if(*p_evt_write->data == 0x02)
            {
                nrf_gpio_pin_set(LED_3);
            }
            else
            {
              //Do nothing
            }
        }
        // Check if the Custom value CCCD is written to and that the value is the appropriate length, i.e 2 bytes.
        if ((p_evt_write->handle == p_cus->custom_value_handles.cccd_handle) && (p_evt_write->len == 2))
        {
            // CCCD written, call application event handler
            if (p_cus->evt_handler != NULL)
            {
                ble_cus_evt_t evt;
                if (ble_srv_is_notification_enabled(p_evt_write->data))
                {
                    evt.evt_type = BLE_CUS_EVT_NOTIFICATION_ENABLED;
                }
                else
                {
                    evt.evt_type = BLE_CUS_EVT_NOTIFICATION_DISABLED;
                }
                // Call the application event handler.
                p_cus->evt_handler(p_cus, &evt);
            }
        }
    }
    
    void ble_cus_on_ble_evt( ble_evt_t const * p_ble_evt, void * p_context)
    {
        ble_cus_t * p_cus = (ble_cus_t *) p_context;
        NRF_LOG_INFO("BLE event received. Event type = %d\r\n", p_ble_evt->header.evt_id);
        if (p_cus == NULL || p_ble_evt == NULL)
        {
            return;
        }
        switch (p_ble_evt->header.evt_id)
        {
            case BLE_GAP_EVT_CONNECTED:
                on_connect(p_cus, p_ble_evt);
                break;
            case BLE_GAP_EVT_DISCONNECTED:
                on_disconnect(p_cus, p_ble_evt);
                break;
            case BLE_GATTS_EVT_WRITE:
                on_write(p_cus, p_ble_evt);
                break;
    /* Handling this event is not necessary
            case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST:
                NRF_LOG_INFO("EXCHANGE_MTU_REQUEST event received.\r\n");
                break;*/
            default:
                // No implementation needed.
                break;
        }
    }
    
    /**@brief Function for adding the Custom Value characteristic.
     * @param[in]   p_cus        Custom Service structure.
     * @param[in]   p_cus_init   Information needed to initialize the service.
     * @return      NRF_SUCCESS on success, otherwise an error code. */
    static uint32_t custom_value_char_add(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
    {
        uint32_t            err_code;
        ble_gatts_char_md_t char_md;
        ble_gatts_attr_md_t cccd_md;
        ble_gatts_attr_t    attr_char_value;
        ble_uuid_t          ble_uuid;
        ble_gatts_attr_md_t attr_md;
    
        // Add Custom Value characteristic
        memset(&cccd_md, 0, sizeof(cccd_md));
    
        //  Read  operation on cccd should be possible without authentication.
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
    
        cccd_md.write_perm = p_cus_init->custom_value_char_attr_md.cccd_write_perm;
        cccd_md.vloc       = BLE_GATTS_VLOC_STACK;
    
        memset(&char_md, 0, sizeof(char_md));
    
        char_md.char_props.read   = 1;
        char_md.char_props.write  = 1;
        char_md.char_props.notify = 1;
        char_md.p_char_user_desc  = NULL;
        char_md.p_char_pf         = NULL;
        char_md.p_user_desc_md    = NULL;
        char_md.p_cccd_md         = &cccd_md;
        char_md.p_sccd_md         = NULL;
    
        ble_uuid.type = p_cus->uuid_type;
        ble_uuid.uuid = CUSTOM_VALUE_CHAR_UUID;
    
        memset(&attr_md, 0, sizeof(attr_md));
    
        attr_md.read_perm  = p_cus_init->custom_value_char_attr_md.read_perm;
        attr_md.write_perm = p_cus_init->custom_value_char_attr_md.write_perm;
        attr_md.vloc       = BLE_GATTS_VLOC_STACK;
        attr_md.rd_auth    = 0;
        attr_md.wr_auth    = 0;
        attr_md.vlen       = 0;
    
        memset(&attr_char_value, 0, sizeof(attr_char_value));
    
        attr_char_value.p_uuid    = &ble_uuid;
        attr_char_value.p_attr_md = &attr_md;
        attr_char_value.init_len  = 29*sizeof(uint8_t);
        attr_char_value.init_offs = 0;
        attr_char_value.max_len   = 29*sizeof(uint8_t);
    
        err_code = sd_ble_gatts_characteristic_add(p_cus->service_handle, &char_md, &attr_char_value, &p_cus->custom_value_handles);
        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
    
        return NRF_SUCCESS;
    }
    
    uint32_t ble_cus_init(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
    {
        if (p_cus == NULL || p_cus_init == NULL)
        {
            return NRF_ERROR_NULL;
        }
        uint32_t   err_code;
        ble_uuid_t ble_uuid;
        // Initialize service structure
        p_cus->evt_handler               = p_cus_init->evt_handler;
        p_cus->conn_handle               = BLE_CONN_HANDLE_INVALID;
        // Add Custom Service UUID
        ble_uuid128_t base_uuid = {CUSTOM_SERVICE_UUID_BASE};
        err_code =  sd_ble_uuid_vs_add(&base_uuid, &p_cus->uuid_type);
        VERIFY_SUCCESS(err_code);
        ble_uuid.type = p_cus->uuid_type;
        ble_uuid.uuid = CUSTOM_SERVICE_UUID;
        // Add the Custom Service
        err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_cus->service_handle);
        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
        // Add Custom Value characteristic
        return custom_value_char_add(p_cus, p_cus_init);
    }
    
    uint32_t ble_cus_custom_value_update(ble_cus_t * p_cus, uint8_t * custom_value)	/*NEW CHANGE*/
    {
        NRF_LOG_INFO("In ble_cus_custom_value_update. \r\n");
        if (p_cus == NULL)
        {
            return NRF_ERROR_NULL;
        }
        uint32_t err_code = NRF_SUCCESS;
        ble_gatts_value_t gatts_value;
        // Initialize value struct.
        memset(&gatts_value, 0, sizeof(gatts_value));
        gatts_value.len     = 29*sizeof(uint8_t);	/*NEW CHANGE*/
        gatts_value.offset  = 0;
        gatts_value.p_value = custom_value;
        // Update database.
        err_code = sd_ble_gatts_value_set(p_cus->conn_handle, p_cus->custom_value_handles.value_handle, &gatts_value);
        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
        // Send value if connected and notifying.
        if ((p_cus->conn_handle != BLE_CONN_HANDLE_INVALID))
        {
            ble_gatts_hvx_params_t hvx_params;
            memset(&hvx_params, 0, sizeof(hvx_params));
            hvx_params.handle = p_cus->custom_value_handles.value_handle;
            hvx_params.type   = BLE_GATT_HVX_NOTIFICATION;
            hvx_params.offset = gatts_value.offset;
            hvx_params.p_len  = &gatts_value.len;
            hvx_params.p_data = gatts_value.p_value;
            err_code = sd_ble_gatts_hvx(p_cus->conn_handle, &hvx_params);
            NRF_LOG_INFO("sd_ble_gatts_hvx result: %x. \r\n", err_code);
    		NRF_LOG_INFO("hvx_params.p_len: %x. \r\n", &hvx_params.p_len);
        }
        else
        {
            err_code = NRF_ERROR_INVALID_STATE;
            NRF_LOG_INFO("sd_ble_gatts_hvx result: NRF_ERROR_INVALID_STATE. \r\n");
        }
        return err_code;
    }
    2068.ble_cus.h

    257070.sdk_config.h

    /**
     * Copyright (c) 2014 - 2018, 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_template_main main.c
     * @{
     * @ingroup ble_sdk_app_template
     * @brief Template project main file.
     *
     * This file contains a template for creating a new application. It has the code necessary to wakeup
     * from button, advertise, get a connection restart advertising on disconnect and if no new
     * connection created go back to system-off mode.
     * It can easily be used as a starting point for creating a new application, the comments identified
     * with 'YOUR_JOB' indicates where and how you can customize.
     */
    
    #include <stdbool.h>
    #include <stdint.h>
    #include <string.h>
    
    #include "nordic_common.h"
    #include "nrf.h"
    #include "app_error.h"
    #include "ble.h"
    #include "ble_hci.h"
    #include "ble_srv_common.h"
    #include "ble_advdata.h"
    #include "ble_advertising.h"
    #include "ble_conn_params.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_soc.h"
    #include "nrf_sdh_ble.h"
    #include "app_timer.h"
    #include "fds.h"
    #include "peer_manager.h"
    #include "peer_manager_handler.h"
    #include "bsp_btn_ble.h"
    #include "sensorsim.h"
    #include "ble_conn_state.h"
    #include "nrf_ble_gatt.h"
    #include "nrf_ble_qwr.h"
    #include "nrf_pwr_mgmt.h"
    
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    
    /*new*/
    #include "ble_cus.h"
    
    #define DEVICE_NAME                     "Forte"                       /**< 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 MIN_CONN_INTERVAL               MSEC_TO_UNITS(100, UNIT_1_25_MS)        /**< Minimum acceptable connection interval (0.1 seconds). */
    #define MAX_CONN_INTERVAL               MSEC_TO_UNITS(200, UNIT_1_25_MS)        /**< Maximum acceptable connection interval (0.2 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. */
    
    /*new*/
    #define NOTIFICATION_INTERVAL           APP_TIMER_TICKS(100)
    
    #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. */
    
    NRF_BLE_GATT_DEF(m_gatt);                                                       /**< GATT module instance. */
    NRF_BLE_QWR_DEF(m_qwr);                                                         /**< Context for the Queued Write module.*/
    /*new*/
    BLE_CUS_DEF(m_cus);
    
    BLE_ADVERTISING_DEF(m_advertising);                                             /**< Advertising module instance. */
    
    APP_TIMER_DEF(m_notification_timer_id);
    
    /*new*/
    uint8_t m_custom_value[29] = {0};
    
    static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID;                        /**< Handle of the current connection. */
    
    /* YOUR_JOB: Declare all services structure your application is using
     *  BLE_XYZ_DEF(m_xyz);
     */
    
    // YOUR_JOB: Use UUIDs for service(s) used in your application.
    /*static ble_uuid_t m_adv_uuids[] =                                               /**< Universally unique service identifiers. */
    /*{
        {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE}
    };*/
    
    /*new*/
    ble_uuid_t m_adv_uuids[] = {{CUSTOM_SERVICE_UUID, BLE_UUID_TYPE_VENDOR_BEGIN }}; /**< Universally unique service identifiers. */
    
    static void advertising_start(bool erase_bonds);
    
    /**@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 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;
        //pm_handler_on_pm_evt(p_evt);
        //pm_handler_flash_clean(p_evt);
        switch (p_evt->evt_id)
        {
    		case PM_EVT_BONDED_PEER_CONNECTED:
            {
                NRF_LOG_INFO("Connected to a previously bonded device.");
            } break;
    		case PM_EVT_CONN_SEC_SUCCEEDED:
            {
                NRF_LOG_INFO("Connection secured: role: %d, conn_handle: 0x%x, procedure: %d.", ble_conn_state_role(p_evt->conn_handle),
                             p_evt->conn_handle, p_evt->params.conn_sec_succeeded.procedure);
            } break;
    		case PM_EVT_CONN_SEC_FAILED:
            {
                /* 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_NO_SPACE_IN_QUEUES)
                {
                    // Retry.
                }
                else
                {
                    APP_ERROR_CHECK(err_code);
                }
            } break;
            case PM_EVT_PEERS_DELETE_SUCCEEDED:
                advertising_start(false);
                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_DATA_UPDATE_SUCCEEDED:
            case PM_EVT_PEER_DELETE_SUCCEEDED:
            case PM_EVT_LOCAL_DB_CACHE_APPLIED:
            case PM_EVT_LOCAL_DB_CACHE_APPLY_FAILED:
                // This can happen when the local DB has changed.
            case PM_EVT_SERVICE_CHANGED_IND_SENT:
            case PM_EVT_SERVICE_CHANGED_IND_CONFIRMED:
            default:
                break;
        }
    }
    
    /**@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 notification_timeout_handler(void * p_context)
    {
        UNUSED_PARAMETER(p_context);
        ret_code_t err_code;
    
        // Increment the value of m_custom_value before nortifing it.
        m_custom_value[0] = 1;
    	m_custom_value[1] = 2;
    	m_custom_value[2] = 3;
    	m_custom_value[3] = 4;
    	m_custom_value[4] = 5;
    	m_custom_value[5] = 6;
    	m_custom_value[6] = 7;
    	m_custom_value[7] = 8;
    	m_custom_value[8] = 9;
    	m_custom_value[9] = 10;
    	m_custom_value[10] = 11;
    	m_custom_value[11] = 12;
    	m_custom_value[12] = 13;
    	m_custom_value[13] = 14;
    	m_custom_value[14] = 15;
    	m_custom_value[15] = 16;
    	m_custom_value[16] = 17;
    	m_custom_value[17] = 18;
    	m_custom_value[18] = 19;
    	m_custom_value[19] = 20;
    	m_custom_value[20] = 21;
    	m_custom_value[21] = 22;
    	m_custom_value[22] = 23;
    	m_custom_value[23] = 24;
    	m_custom_value[24] = 25;
    	m_custom_value[25] = 26;
    	m_custom_value[26] = 27;
    	m_custom_value[27] = 28;
    	m_custom_value[28] = 29;
    
        err_code = ble_cus_custom_value_update(&m_cus, m_custom_value);
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for the Timer initialization.
     *
     * @details Initializes the timer module. This creates and starts application timers.
     */
    static void timers_init(void)
    {
        // Initialize timer module.
        ret_code_t err_code = app_timer_init();
        APP_ERROR_CHECK(err_code);
    
        // Create timers.
        err_code = app_timer_create(&m_notification_timer_id, APP_TIMER_MODE_REPEATED, notification_timeout_handler);
        APP_ERROR_CHECK(err_code);
    	
        /* YOUR_JOB: Create any timers to be used by the application.
                     Below is an example of how to create a timer.
                     For every new timer needed, increase the value of the macro APP_TIMER_MAX_TIMERS by
                     one.
           ret_code_t err_code;
           err_code = app_timer_create(&m_app_timer_id, APP_TIMER_MODE_REPEATED, timer_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);
        /* YOUR_JOB: Use an appearance value matching the application's use case.
           err_code = sd_ble_gap_appearance_set(BLE_APPEARANCE_);
           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 handling the YYY Service events.
     * YOUR_JOB implement a service handler function depending on the event the service you are using can generate
     *
     * @details This function will be called for all YY Service events which are passed to
     *          the application.
     *
     * @param[in]   p_yy_service   YY Service structure.
     * @param[in]   p_evt          Event received from the YY Service.
     *
     *
    static void on_yys_evt(ble_yy_service_t     * p_yy_service,
                           ble_yy_service_evt_t * p_evt)
    {
        switch (p_evt->evt_type)
        {
            case BLE_YY_NAME_EVT_WRITE:
                APPL_LOG("[APPL]: charact written with value %s. ", p_evt->params.char_xx.value.p_str);
                break;
    
            default:
                // No implementation needed.
                break;
        }
    }*/
    
    /**@brief Function for handling the Custom Service Service events.
     * @details This function will be called for all Custom Service events which are passed to the application.
     * @param[in]   p_cus_service  Custom Service structure.
     * @param[in]   p_evt          Event received from the Custom Service. */
    static void on_cus_evt(ble_cus_t     * p_cus_service, ble_cus_evt_t * p_evt)
    {
        ret_code_t err_code;
        switch(p_evt->evt_type)
        {
            case BLE_CUS_EVT_NOTIFICATION_ENABLED:
                 err_code = app_timer_start(m_notification_timer_id, NOTIFICATION_INTERVAL, NULL);
                 APP_ERROR_CHECK(err_code);
                 break;
            case BLE_CUS_EVT_NOTIFICATION_DISABLED:
                err_code = app_timer_stop(m_notification_timer_id);
                APP_ERROR_CHECK(err_code);
                break;
            case BLE_CUS_EVT_CONNECTED:
                break;
            case BLE_CUS_EVT_DISCONNECTED:
                  break;
            default:
                  // No implementation needed.
                  break;
        }
    }
    
    /**@brief Function for initializing services that will be used by the application.
     */
    static void services_init(void)
    {
        ret_code_t         err_code;
        nrf_ble_qwr_init_t qwr_init = {0};
    	ble_cus_init_t      cus_init = {0};/*new*/
        // 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 CUS Service init structure to zero.
        cus_init.evt_handler                = on_cus_evt;
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.cccd_write_perm);
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.read_perm);
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.write_perm);
        err_code = ble_cus_init(&m_cus, &cus_init);
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling the Connection Parameters Module.
     *
     * @details This function will be called for all events in the Connection Parameters Module which
     *          are passed to the application.
     *          @note All this function does is to disconnect. This could have been done by simply
     *                setting the disconnect_on_fail config parameter, but instead we use the event
     *                handler mechanism to demonstrate its use.
     *
     * @param[in] p_evt  Event received from the Connection Parameters Module.
     */
    static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
    {
        ret_code_t err_code;
        if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
        {
            err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
            APP_ERROR_CHECK(err_code);
        }
    }
    
    /**@brief Function for handling a Connection Parameters error.
     *
     * @param[in] nrf_error  Error code containing information about what went wrong.
     */
    static void conn_params_error_handler(uint32_t nrf_error)
    {
        APP_ERROR_HANDLER(nrf_error);
    }
    
    /**@brief Function for initializing the Connection Parameters module.
     */
    static void conn_params_init(void)
    {
        ret_code_t             err_code;
        ble_conn_params_init_t cp_init;
        memset(&cp_init, 0, sizeof(cp_init));
        cp_init.p_conn_params                  = NULL;
        cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
        cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
        cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
        cp_init.start_on_notify_cccd_handle    = 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 starting timers.
     */
    static void application_timers_start(void)
    {
        /* YOUR_JOB: Start your timers. below is an example of how to start a timer.
           ret_code_t err_code;
           err_code = app_timer_start(m_app_timer_id, TIMER_INTERVAL, NULL);
           APP_ERROR_CHECK(err_code); */
    }
    
    /**@brief Function for putting the chip into sleep mode.
     *
     * @note This function will not return.
     */
    static void sleep_mode_enter(void)
    {
        ret_code_t err_code;
        err_code = bsp_indication_set(BSP_INDICATE_IDLE);
        APP_ERROR_CHECK(err_code);
        // Prepare wakeup buttons.
        err_code = bsp_btn_ble_sleep_mode_prepare();
        APP_ERROR_CHECK(err_code);
        // Go to system-off mode (this function will not return; wakeup will cause a reset).
        err_code = sd_power_system_off();
        APP_ERROR_CHECK(err_code);
    }
    
    /**@brief Function for handling advertising events.
     *
     * @details This function will be called for advertising events which are passed to the application.
     *
     * @param[in] ble_adv_evt  Advertising event.
     */
    static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
    {
        ret_code_t err_code;
        switch (ble_adv_evt)
        {
            case BLE_ADV_EVT_FAST:
                NRF_LOG_INFO("Fast advertising.");
                err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
                APP_ERROR_CHECK(err_code);
                break;
            case BLE_ADV_EVT_IDLE:
                sleep_mode_enter();
                break;
            default:
                break;
        }
    }
    
    /**@brief Function for handling BLE events.
     *
     * @param[in]   p_ble_evt   Bluetooth stack event.
     * @param[in]   p_context   Unused.
     */
    static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
    {
        ret_code_t err_code = NRF_SUCCESS;
    
        switch (p_ble_evt->header.evt_id)
        {
            case BLE_GAP_EVT_DISCONNECTED:
                NRF_LOG_INFO("Disconnected.");
                // LED indication will be changed when advertising starts.
                break;
    
            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_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 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 Peer Manager initialization.
     */
    static void peer_manager_init(void)
    {
        ble_gap_sec_params_t sec_param;
        ret_code_t           err_code;
    
        err_code = pm_init();
        APP_ERROR_CHECK(err_code);
    
        memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));
    
        // Security parameters to be used for all security procedures.
        sec_param.bond           = SEC_PARAM_BOND;
        sec_param.mitm           = SEC_PARAM_MITM;
        sec_param.lesc           = SEC_PARAM_LESC;
        sec_param.keypress       = SEC_PARAM_KEYPRESS;
        sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
        sec_param.oob            = SEC_PARAM_OOB;
        sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
        sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
        sec_param.kdist_own.enc  = 1;
        sec_param.kdist_own.id   = 1;
        sec_param.kdist_peer.enc = 1;
        sec_param.kdist_peer.id  = 1;
    
        err_code = pm_sec_params_set(&sec_param);
        APP_ERROR_CHECK(err_code);
    
        err_code = pm_register(pm_evt_handler);
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Clear 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 handling events from the BSP module.
     *
     * @param[in]   event   Event generated when button is pressed.
     */
    static void bsp_event_handler(bsp_event_t event)
    {
        ret_code_t err_code;
    
        switch (event)
        {
            case BSP_EVENT_SLEEP:
                sleep_mode_enter();
                break; // BSP_EVENT_SLEEP
    
            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; // BSP_EVENT_DISCONNECT
    
            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; // BSP_EVENT_KEY_0
    
            default:
                break;
        }
    }
    
    
    /**@brief Function for initializing the Advertising functionality.
     */
    static void advertising_init(void)
    {
        ret_code_t             err_code;
        ble_advertising_init_t init;
    
        memset(&init, 0, sizeof(init));
    
        init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
        init.advdata.include_appearance      = true;
        init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
        init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
        init.advdata.uuids_complete.p_uuids  = m_adv_uuids;
    
        init.config.ble_adv_fast_enabled  = true;
        init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
        init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;
    
        init.evt_handler = on_adv_evt;
    
        err_code = ble_advertising_init(&m_advertising, &init);
        APP_ERROR_CHECK(err_code);
    
        ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
    }
    
    /**@brief Function for initializing buttons and leds.
     *
     * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
     */
    static void buttons_leds_init(bool * p_erase_bonds)
    {
        ret_code_t err_code;
        bsp_event_t startup_event;
    
        err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
        APP_ERROR_CHECK(err_code);
    
        err_code = bsp_btn_ble_init(NULL, &startup_event);
        APP_ERROR_CHECK(err_code);
    
        *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
    }
    
    
    /**@brief Function for initializing the nrf log module.
     */
    static void log_init(void)
    {
        ret_code_t err_code = NRF_LOG_INIT(NULL);
        APP_ERROR_CHECK(err_code);
    
        NRF_LOG_DEFAULT_BACKENDS_INIT();
    }
    
    
    /**@brief Function for initializing power management.
     */
    static void power_management_init(void)
    {
        ret_code_t err_code;
        err_code = nrf_pwr_mgmt_init();
        APP_ERROR_CHECK(err_code);
    }
    
    
    /**@brief Function for handling the idle state (main loop).
     *
     * @details If there is no pending log operation, then sleep until next the next event occurs.
     */
    static void idle_state_handle(void)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            nrf_pwr_mgmt_run();
        }
    }
    
    /**@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_DELETED_SUCEEDED event
        }
        else
        {
            ret_code_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
            APP_ERROR_CHECK(err_code);
        }
    }
    
    /**@brief Function for application main entry. */
    int main(void)
    {
        bool erase_bonds;
        // Initialize.
        log_init();
        timers_init();
        buttons_leds_init(&erase_bonds);
        power_management_init();
        ble_stack_init();
        gap_params_init();
        gatt_init();
    	services_init();	/*new*/
        advertising_init();
        //services_init();
        conn_params_init();
        peer_manager_init();
    
        // Start execution.
        NRF_LOG_INFO("Template example started.");
        application_timers_start();
    
        advertising_start(erase_bonds);
    
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    
    
    /**
     * @}
     */
    

  • I suggest you look into the ble_app_uart example to see how to send more than 20 bytes. Increasing these:

    #define NRF_SDH_BLE_GAP_DATA_LENGTH 36

    #define NRF_SDH_BLE_GATT_MAX_MTU_SIZE 32

    BLE_GATT_ATT_MTU_DEFAULT = 32 define in ble_gatt.h

    may require you to change your ram settings again.

     

    bscdb said:
    Also how do I receive 20 bytes from host? Right now its just a byte.

     To see how to "receive more than one byte", please refer to the ble_app_uart_c example. You probably receive more than one byte, but you need to look at the length field. Please check the function ble_nus_c_evt_handler() and the event BLE_NUS_C_EVT_NUS_TX_EVT. The data is located in p_ble_nus_evt->p_data,  and the length of the data is found in p_ble_nus_evt->data_len.

    Best regards,

    Edvin

Reply
  • I suggest you look into the ble_app_uart example to see how to send more than 20 bytes. Increasing these:

    #define NRF_SDH_BLE_GAP_DATA_LENGTH 36

    #define NRF_SDH_BLE_GATT_MAX_MTU_SIZE 32

    BLE_GATT_ATT_MTU_DEFAULT = 32 define in ble_gatt.h

    may require you to change your ram settings again.

     

    bscdb said:
    Also how do I receive 20 bytes from host? Right now its just a byte.

     To see how to "receive more than one byte", please refer to the ble_app_uart_c example. You probably receive more than one byte, but you need to look at the length field. Please check the function ble_nus_c_evt_handler() and the event BLE_NUS_C_EVT_NUS_TX_EVT. The data is located in p_ble_nus_evt->p_data,  and the length of the data is found in p_ble_nus_evt->data_len.

    Best regards,

    Edvin

Children
  • Hi Edvin, I have already mentioned above that I made these changes -

    #define NRF_SDH_BLE_GAP_DATA_LENGTH 36

    #define NRF_SDH_BLE_GATT_MAX_MTU_SIZE 32

    BLE_GATT_ATT_MTU_DEFAULT = 32 define in ble_gatt.h

    may require you to change your ram settings again.

    But still it does not send more than 20 bytes.

  • Ok. How do you determine that you are just able to send 20 bytes? I do believe you, but I want to know what symptoms you are seeing.

  • I checked it on nrfconnect. Even I was thinking the same that I'm correctly sending 29 bytes, may be nrfconnect does not display them?

    Can you check at your end if its the same?

    I also receive only 20 bytes from host. So both ways its restricted to 20 bytes only.

    For receiving 29 bytes, I changed the code to-

    static void on_write(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
    {
    	ble_gatts_evt_write_t const * p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;
        // Custom Value Characteristic Written to.
        if (p_evt_write->handle == p_cus->custom_value_handles.value_handle)
        {
            nrf_gpio_pin_toggle(LED_4);
    		for(int i = 0; i < p_evt_write->len; i++)
    		{
    			NRF_LOG_INFO("Data Received: %d", p_evt_write->data[i]);
    		}
            /*if(*p_evt_write->data == 0x01)
            {
                nrf_gpio_pin_clear(LED_3);
            }
            else if(*p_evt_write->data == 0x02)
            {
                nrf_gpio_pin_set(LED_3);
            }
            else
            {
              //Do nothing
            }*/
        }
        // Check if the Custom value CCCD is written to and that the value is the appropriate length, i.e 2 bytes.
        if ((p_evt_write->handle == p_cus->custom_value_handles.cccd_handle) && (p_evt_write->len == 2))
        {
            // CCCD written, call application event handler
            if (p_cus->evt_handler != NULL)
            {
                ble_cus_evt_t evt;
                if (ble_srv_is_notification_enabled(p_evt_write->data))
                {
                    evt.evt_type = BLE_CUS_EVT_NOTIFICATION_ENABLED;
                }
                else
                {
                    evt.evt_type = BLE_CUS_EVT_NOTIFICATION_DISABLED;
                }
                // Call the application event handler.
                p_cus->evt_handler(p_cus, &evt);
            }
        }
    }

    When I send more than 20 bytes from nrfConnect, I get a message saying 

    When I was debugging, I got 

    Could you please check at your end? I cant seem to find any solution to this.

    ble_app_template_custom_packet.zip

    I'm using SDK15.2. My thinking is that the updated MTU size is not being exchanged between peripheral & central.

  • I tested your project against nRF Connect for Desktop:

    I was able to both receive and send 29 bytes.

    Does it not behave the same in your case?

  • Nope thats strange, it does not. I also checked with my Android code & Microsoft's BLE Explorer tool. Were you consistently seeing this behavior or just one time? Did you use nrf52 DK? I used nrf52 for above code & nrf51 DK with nrfConnect & couldnt see more than 20 bytes being passed both ways. Could you please try the same or with different host code?

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