Not receiving BLE NUS data on the nRF Toolbox app; getting 0x04 error code from app_uart_put().

[nikostpn]

Hi,

I'm using the Nordic DK52 (52832) along with SDK 15.0 to prototype an application where I can send some data from a sensor attached via UART to an BLE-enabled application. I'm using nRF Toolbox with the Serial feature to test whether I'm getting any data sent from the sensor. I am using SESV4.22 for the development of the application.

I've started out with the ble_app_uart example and attempted to modify it to my needs. Below I'm providing code snippets where I changed the functions; everything else is unchanged:

//Send this to the sensor to initiate a measurement
static uint8_t const readLiveDataCmd[] = {0x16, 0x13, 0x2D, 0x10, 0x1F, 0x00, 0x7E};

//Don't care if data is sent to the board
static void nus_data_handler(ble_nus_evt_t * p_evt)
{

    /*if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        uint32_t err_code;

        NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
        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]);
                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);
        }
        /*if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }*/
    //}
}

void uart_event_handle(app_uart_evt_t * p_event)
{
    static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
    static uint8_t index = 0;
    float          temperature = 0;
    float          pressure = 0;
    uint8_t        data[64];
    uint32_t       err_code;
    


    switch (p_event->evt_type)
    {
        case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&data_array[index]));
            index++;

            if ((data_array[index - 4] == (uint16_t) 0x10) && (data_array[index-3] == (uint16_t) 0x1F))
            {
                NRF_LOG_DEBUG("Got Sensor Readings");
                NRF_LOG_HEXDUMP_DEBUG(data_array, index);
                
                union {
                char c[4];
                float f;
                } u;
                
                u.c[0] = data_array[7];
                u.c[1] = data_array[8];
                u.c[2] = data_array[9];
                u.c[3] = data_array[10];

                pressure = u.f;

                u.c[0] = data_array[11];
                u.c[1] = data_array[12];
                u.c[2] = data_array[13];
                u.c[3] = data_array[14]; 

                temperature = u.f;
                
                
                /*Send the temp and pressure data to the BLE*/
                do
                { 
                    sprintf((char*) data,"Temperature: %f; Pressure: %f", temperature, pressure);
                    uint16_t length = (uint16_t)sizeof(data);
                    err_code = ble_nus_data_send(&m_nus, data, &length, m_conn_handle);
                    if ( (err_code != NRF_ERROR_INVALID_STATE) && (err_code != NRF_ERROR_BUSY) &&
                         (err_code != NRF_ERROR_NOT_FOUND) )
                    {
                        APP_ERROR_CHECK(err_code);
                    }
                } while (err_code == NRF_ERROR_BUSY);

                index = 0;
            }
            break;

        case APP_UART_COMMUNICATION_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_communication);
            break;

        case APP_UART_FIFO_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_code);
            break;

        default:
            break;
    }
}

//main
int main(void)
{
    bool erase_bonds;

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

    // Start execution.
    //printf("\r\nUART started.\r\n");
    NRF_LOG_INFO("Debug logging for UART over RTT started.");
    advertising_start();

    // Enter main loop.
    for (;;)
    { 
        //idle_state_handle();
        uint32_t err_code;
        for(uint8_t i = 0; i < sizeof(readLiveDataCmd); i++)
        {
          do
          {
            err_code = app_uart_put(readLiveDataCmd[i]);
             if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                  {
                      if(err_code == 0x04)
                      {
                        break;
                      }
                      else
                      {
                        APP_ERROR_CHECK(err_code);
                      }
                  }
          } while (err_code == NRF_ERROR_BUSY);
        }
    }
}

When I run the app as is, I can see the advertisement in the nRF Toolbox and I can connect to the board, but I get nothing transmitted from the sensor. When I try to debug the application, I get an error 0x04 returned a from the app_uart_put() function.

What did I miss in my program?

[nikostpn]

Edvin,

Seemingly, that one time I had a glitch where the way I set the breakpoints, I wasn't seeing the 0x04 returned from app_fifo_put(); however, putting a repeated application timer into the main to call onto the sensor once a second has solved my problem--I am able to successfully get readings in the nRF Toolbox app.

Thank you so much!