RE: HOW TO READ FROM MULTIPLE BLE CHARACTER

Hung Bui — Thu, 18 Jul 2019 08:39:32 GMT

I don't think "D/BluetoothLeScanner: could not find callback wrapper " has anything to do with reading the characteristic. You can read more about it here.

Did you do Service Discovery on your Android app and found all 3 services ? Could you show the code on how you read the characteristic ? What value do you expected to see ? Because in NUS service we don't usually read, we do write and notification.

RE: HOW TO READ FROM MULTIPLE BLE CHARACTER

Nahom — Wed, 17 Jul 2019 15:01:28 GMT

I already create my service and my characteristics. Even i checked all the services and characteristics using nRFConnect if they work good. They work perfect. On my android phone i am able to discover all the characteristics and services but i am not able to read the values. as you can seen on my android console all the connection setup ed correctly but when it tries to read the values it gives this warning.

D/BluetoothLeScanner: could not find callback wrapper

if you see my ble_app_uart code i am using one nus_data_handler for all the services

static void nus_data_handler(ble_nus_evt_t * p_evt)
{
    if ((p_evt->type == BLE_NUS_EVT_RX_DATA) && (isConnected))
    {
      
       first_ser = true;
      Recieved_command_Start = true;
      if(p_evt->params.rx_data.length > 2)
      {
       
        NRF_LOG_INFO(" first character should st");
        
       third_ser =false;
       second_ser = false;
        Report_command_send = false;
        Version_command_send = false;
      }
        uint32_t err_code;
        memset (lastCommand, 0, 256);
        strncpy (lastCommand, (char *) p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
//        printf("%s\r\n", lastCommand);        
        //NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            do
            {
                err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
              // NRF_LOG_INFO("Data ver is set to %c  :(%d)",lastCommand[i],p_evt->params.rx_data.length);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        
        while (app_uart_put('\r') == NRF_ERROR_BUSY);
        NRF_LOG_INFO("Command sent %s ", lastCommand);
     
    }

 /*----------------------------------------------------------------------------------------------------------------*/
  if ( (p_evt->type == BLE_NUS_EVT_TX_RDY) && (isConnected) && (Version_command_send))
  {
     NRF_LOG_INFO(" second character should st");
    second_ser = true;
    third_ser = false;
    //first_ser = false;
    Report_command_send = false;
    Version_command_send = false;
    size_t length = sizeof(version) / sizeof(version[0]);
    int i;
    uint32_t   err_code;
         memset (lastCommand, 0, 256);
        strncpy (lastCommand, (char *) version,length-1);

        for (i = 0; i < length-1; i++)
        {
            do
            {
                err_code = app_uart_put(version[i]);
               // NRF_LOG_INFO("Data ver is set to 0x%X(%d)", version[i],length-1);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        
        while (app_uart_put('\r') == NRF_ERROR_BUSY);
        NRF_LOG_INFO("Command sent %s (%d)", version,length-1);
        
    
  }

/*---------------------------------------------------------------------------------------------------------------*/

  if ((p_evt->type == BLE_NUS_EVT_TX_RDY) && (isConnected) && (Report_command_send))
  {
    third_ser = true;
    NRF_LOG_INFO(" Third character should st");
    //first_ser = false;
    second_ser = false;
    Report_command_send = false;
    size_t length = sizeof(report) / sizeof(report[0]);
    int i;
    uint32_t   err_code;
         memset (lastCommand, 0, 256);
        strncpy (lastCommand, (char *) report,length-1);

        for (i = 0; i < length-1; i++)
        {
            do
            {
                err_code = app_uart_put(report[i]);
               // NRF_LOG_INFO("Data ver is set to 0x%X(%d)", report[i],length-1);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        
        NRF_LOG_INFO("Command sent %s (%d)", report,length-1);
        while (app_uart_put('\r') == NRF_ERROR_BUSY); 
  }
}

static void services_init(void)
{
    uint32_t           err_code;
    uint32_t           err_code_2;
    ble_nus_init_t     nus_init;
    nrf_ble_qwr_init_t qwr_init = {0};
    //ble_nus_init_2(&m_nus);
   // ble_nus_init_3(&m_nus);
   

    // 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 NUS.
    memset(&nus_init, 0, sizeof(nus_init));

    nus_init.data_handler = nus_data_handler;
   
    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);

    err_code = ble_nus_init_2(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);

    err_code = ble_nus_init_3(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);
    
  
}

RE: HOW TO READ FROM MULTIPLE BLE CHARACTER

Hung Bui — Wed, 17 Jul 2019 11:54:41 GMT

Please clarify, where do you want your services located ?

On the nRF52 or on the Phone ?

I don't see any problem having multiple services on the nRF52.

Please test and verify that it works using nRFConnect before you write your Android app.

RE: HOW TO READ FROM MULTIPLE BLE CHARACTER

Nahom — Tue, 16 Jul 2019 13:47:44 GMT

ya i saw it. but it is only use one service and two characteristics. I need a sample example for how to read from multiple services which have notifiable characteristics.

please tell me how to read from multiple services and how can i modified my app_uart nrf52 example for sending data to different services.

RE: HOW TO READ FROM MULTIPLE BLE CHARACTER

Hung Bui — Tue, 16 Jul 2019 12:49:32 GMT

Hi Nahom,

The Android-nRF-UART is very old code and should not be used. You should use the UART profile inside nRFToolbox instead.

Have you tried to test with nRFToolbox ?

Do you have the same issue when you test the Android-nRF-UART app with the stock ble_app_uart example ?