ble_nus_data_send sending the wrong data

RE: ble_nus_data_send sending the wrong data

nl671dev — Tue, 15 Nov 2022 13:54:14 GMT

I think I have it solved now. In the line ble_nus_data_send(&m_nus, counter_char, &length, m_conn_handle), length was set to BLE_NUS_MAX_DATA_LEN, which is some large number. I set length to 4 (the program should terminate before the counter reaches 1000), and the output is correct as far as I know. My code is posted below for reference.

void count_up();
volatile int up_counter = 0;

void count_up()
{
    //int length = BLE_NUS_MAX_DATA_LEN;
    int length = 4;
    ble_conn_state_conn_handle_list_t conn_handles = ble_conn_state_periph_handles();
    uint32_t err_code;
    char counter_char[20];
    //uint32_t time_err_code;
    //static uint32_t timeout = 0;
    

    for (uint8_t i=m_last_successful_conn_handle; i<conn_handles.len; i++)
    {
        itoa(up_counter, counter_char, 10);
        //NRF_LOG_DEBUG("Integer: %d   Converted String: %c\n", up_counter, counter_char);
        err_code = ble_nus_data_send(&m_nus, counter_char, &length, m_conn_handle);

        if(err_code == NRF_SUCCESS)
        {
            m_last_successful_conn_handle++;
        }
        else if (err_code == NRF_ERROR_RESOURCES)
        {
            // Queue is full. Break the loop, and countinue with the m_last_successful_conn_handle after TX_COMPLETE
            break;
        }
        //err_code = ble_nus_data_send(&m_nus, up_counter, &length, m_conn_handle);
        
    }
    
    if (m_last_successful_conn_handle == conn_handles.len)
    {
        m_last_successful_conn_handle = 0;
    }

    if(up_counter == 255)
    {
        up_counter == 0;
    } else
    {
        up_counter++;
    }
}

Thank you for your help.

RE: ble_nus_data_send sending the wrong data

nl671dev — Tue, 15 Nov 2022 13:27:55 GMT

Thank you for answering. I have tried to implement the itoa function, but it doesnt seem to be working. The output to my phone still looks the same. I even tried to look at the output in the debugger, and it's also incorrect. I posted my code and the debugger output below. Do you see whether I did something wrong?

void count_up();
int up_counter = 0;

void count_up()
{
    int length = BLE_NUS_MAX_DATA_LEN;
    ble_conn_state_conn_handle_list_t conn_handles = ble_conn_state_periph_handles();
    uint32_t err_code;
    char counter_char[sizeof(int)*8+1];
    //uint32_t time_err_code;
    //static uint32_t timeout = 0;
    

    for (uint8_t i=m_last_successful_conn_handle; i<conn_handles.len; i++)
    {
        itoa(up_counter, counter_char, 10);
        NRF_LOG_DEBUG("Converted String: %c", counter_char);
        err_code = ble_nus_data_send(&m_nus, counter_char, &length, m_conn_handle);

        if(err_code == NRF_SUCCESS)
        {
            m_last_successful_conn_handle++;
        }
        else if (err_code == NRF_ERROR_RESOURCES)
        {
            // Queue is full. Break the loop, and countinue with the m_last_successful_conn_handle after TX_COMPLETE
            break;
        }
        
    }
    
    if (m_last_successful_conn_handle == conn_handles.len)
    {
        m_last_successful_conn_handle = 0;
    }

    if(up_counter == 255)
    {
        up_counter == 0;
    } else
    {
        up_counter++;
    }
}

Thank you.

Edit: removed a line from the code that was obviously wrong. The output is still the same, unfortunately.

RE: ble_nus_data_send sending the wrong data

Einar Thorsrud — Tue, 15 Nov 2022 12:38:52 GMT

Hi,

Your up_counter is an uint8_t, starting from 0. So you are sending raw numbers, not ascii characters. When the receiver prints these as if they were ascii characters, that will result in a lot of strange charcters and is expected. I assume what you want to do is send an ascii representatnion of th enumber? If so, use snprintf() or itoa() or similar to convert it to a string before sending it with ble_nus_data_send().