nordic nus service에 READ characteristic 추가

 

battery level 만 read하고 싶어

read할 수 있는 새  Characteristic을 추가 하였음

 

• blle_nus.h

/**@brief   Nordic UART Service structure.
 *
 * @details This structure contains status information related to the service.
 */
struct ble_nus_s
{
    uint8_t                         uuid_type;      
    uint16_t                        service_handle; 
    ble_gatts_char_handles_t        tx_handles;     
    ble_gatts_char_handles_t        rx_handles;      
    ble_gatts_char_handles_t        bat_handles;     //added   
    blcm_link_ctx_storage_t * const p_link_ctx_storage; 
    ble_nus_data_handler_t          data_handler;   
};

struct ble_nus_s에

ble_gatts_char_handles_t        bat_handles; 추가

 

• ble_nus.c

#define BLE_UUID_NUS_BAT_CHARACTERISTIC 0x0004      //add
#define BLE_UUID_NUS_TX_CHARACTERISTIC  0x0003      /**< The UUID of the TX Characteristic. */
#define BLE_UUID_NUS_RX_CHARACTERISTIC  0x0002      /**< The UUID of the RX Characteristic. */


uint32_t ble_nus_init(ble_nus_t * p_nus, ble_nus_init_t const * p_nus_init)
{
    ret_code_t            err_code;
    ble_uuid_t            ble_uuid;
    ble_uuid128_t         nus_base_uuid = NUS_BASE_UUID;
    ble_add_char_params_t add_char_params;

    VERIFY_PARAM_NOT_NULL(p_nus);
    VERIFY_PARAM_NOT_NULL(p_nus_init);

    // Initialize the service structure.
    p_nus->data_handler = p_nus_init->data_handler;

    /**@snippet [Adding proprietary Service to the SoftDevice] */
    // Add a custom base UUID.
    err_code = sd_ble_uuid_vs_add(&nus_base_uuid, &p_nus->uuid_type);
    VERIFY_SUCCESS(err_code);

    ble_uuid.type = p_nus->uuid_type;
    ble_uuid.uuid = BLE_UUID_NUS_SERVICE;

    // Add the service.
    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY,
                                        &ble_uuid,
                                        &p_nus->service_handle);
    /**@snippet [Adding proprietary Service to the SoftDevice] */
    VERIFY_SUCCESS(err_code);

    // Add the RX Characteristic.
    memset(&add_char_params, 0, sizeof(add_char_params));
    add_char_params.uuid                     = BLE_UUID_NUS_RX_CHARACTERISTIC;
    add_char_params.uuid_type                = p_nus->uuid_type;
    add_char_params.max_len                  = BLE_NUS_MAX_RX_CHAR_LEN;
    add_char_params.init_len                 = sizeof(uint8_t);
    add_char_params.is_var_len               = true;
    add_char_params.char_props.write         = 1;
    add_char_params.char_props.write_wo_resp = 1;

    add_char_params.read_access  = SEC_OPEN;
    add_char_params.write_access = SEC_OPEN;

    err_code = characteristic_add(p_nus->service_handle, &add_char_params, &p_nus->rx_handles);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }

    // Add the TX Characteristic.
    /**@snippet [Adding proprietary characteristic to the SoftDevice] */
    memset(&add_char_params, 0, sizeof(add_char_params));
    add_char_params.uuid              = BLE_UUID_NUS_TX_CHARACTERISTIC;
    add_char_params.uuid_type         = p_nus->uuid_type;
    add_char_params.max_len           = BLE_NUS_MAX_TX_CHAR_LEN;
    add_char_params.init_len          = sizeof(uint8_t);
    add_char_params.is_var_len        = true;
    add_char_params.char_props.notify = 1;

    add_char_params.read_access       = SEC_OPEN;
    add_char_params.write_access      = SEC_OPEN;
    add_char_params.cccd_write_access = SEC_OPEN;

    err_code = characteristic_add(p_nus->service_handle, &add_char_params, &p_nus->tx_handles);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }


    // Add Battery Level Characteristic.
    memset(&add_char_params, 0, sizeof(add_char_params));
    add_char_params.uuid              = BLE_UUID_NUS_BAT_CHARACTERISTIC;
    add_char_params.uuid_type         = p_nus->uuid_type;
    add_char_params.max_len           = BLE_NUS_MAX_TX_CHAR_LEN;
    add_char_params.init_len          = sizeof(uint8_t);
    add_char_params.is_var_len        = true;
    add_char_params.char_props.read   = 1;
    add_char_params.is_defered_read   = 1;
    add_char_params.read_access       = SEC_OPEN;

    return characteristic_add(p_nus->service_handle, &add_char_params, &p_nus->bat_handles);
    /**@snippet [Adding proprietary characteristic to the SoftDevice] */
}

 

보면 마지막에 Characteristic을 추가하였다.

read property를 추가하여야 하기 때문에

add_char_params.char_props.read   = 1;
add_char_params.is_defered_read   = 1;
add_char_params.read_access       = SEC_OPEN;

를 추가해주면 된다.

uuid랑 ble_gatts_char_handles_t(&p_nus->bat_handles) 를 다르게 추가함을 잊지 말아야 함.

 

 

 

• main.c

...

static void on_authorize_request(ble_evt_t const * p_ble_evt);

...

/**@brief Function for handling the Read/Write Authorization request event.
 *
 * @param[in] p_ble_evt Event received from the BLE stack.
 */
static void on_authorize_request(ble_evt_t const * p_ble_evt)
{
    ble_gatts_rw_authorize_reply_params_t        reply_params;
      ble_gatts_evt_rw_authorize_request_t const * p_evt_rw_auth = &p_ble_evt->evt.gatts_evt.params.authorize_request;

      memset (&reply_params, 0, sizeof(ble_gatts_rw_authorize_reply_params_t));

      if (p_evt_rw_auth->type == BLE_GATTS_AUTHORIZE_TYPE_READ)
      {
          uint8_t bat_arr[3] = {0,};
          bat_arr[0] = 0xa5;
          bat_arr[1] = 0x06;
          bat_arr[2] = bat_level;
          reply_params.type = BLE_GATTS_AUTHORIZE_TYPE_READ;
          reply_params.params.read.gatt_status = BLE_GATT_STATUS_SUCCESS;
          reply_params.params.read.update = 1;
          reply_params.params.read.len = 3;
          reply_params.params.read.offset = p_evt_rw_auth->request.read.offset;
          reply_params.params.read.p_data = bat_arr;
          (void) sd_ble_gatts_rw_authorize_reply(p_ble_evt->evt.common_evt.conn_handle, &reply_params);
          
     }
}



...

static void ble_evt_handler(ble_evt_t const *p_ble_evt, void *p_context)
{
...
	case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST:
        NRF_LOG_DEBUG("BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST");
        on_authorize_request(p_ble_evt);
        break;
...
}

 

삽질끝에 uint8_t bat_level을 reply로 보내는데 성공하였다.

추가해아할 점만 포스팅 하였음.!