RE: app_trace_init not returning useful value if debugging disabled

Vidar Berg — Mon, 30 Nov 2015 13:32:23 GMT

Hi, the documentation doesn't seem to correspond to actual implementation in the SDK. In the SDK (ble_app_hrs) app_trace is defined as app_trace_init(...) when ENABLE_DEBUG_LOG_SUPPORT is not defined, hence doing nothing. Also, it doesn't return any error code in case of assert. Will report this internally.

Normally app_trace_init() shouldn't fail unless it has been modified in some way which is why it's a void function. However, if it does fail I think it's better to catch the error by passing it to the APP_ERROR_CHECK() macro :

void app_trace_init(void)
{
    uint32_t err_code = NRF_SUCCESS;
    const app_uart_comm_params_t comm_params =  
    {
        RX_PIN_NUMBER, 
        TX_PIN_NUMBER, 
        RTS_PIN_NUMBER, 
        CTS_PIN_NUMBER, 
        APP_UART_FLOW_CONTROL_DISABLED, 
        false, 
        UART_BAUDRATE_BAUDRATE_Baud38400
    }; 
        
    APP_UART_FIFO_INIT(&comm_params, 
                       UART_RX_BUF_SIZE, 
                       UART_TX_BUF_SIZE, 
                       uart_error_handle, 
                       APP_IRQ_PRIORITY_LOW,
                       err_code);
   //UNUSED_VARIABLE(err_code);
   APP_ERROR_CHECK(err_code);
}

Then in case of assert, the app_error.c->app_error_handler() will be called with the error code passed as an argument. The list of error codes are found in nrf_error.h, and can be used to determine the reason for the assert.