NRF51822 UART hangs and requires power cycle

RE: NRF51822 UART hangs and requires power cycle

MartinBL — Mon, 11 Dec 2017 13:31:42 GMT

You should check what kind of events you get in the error handler:

void uart_error_handle_A(app_uart_evt_t * p_event)
{
    if (p_event->evt_type == APP_UART_COMMUNICATION_ERROR)
    {
        APP_ERROR_HANDLER(p_event->data.error_communication);
    }
    else if (p_event->evt_type == APP_UART_FIFO_ERROR)
    {
        APP_ERROR_HANDLER(p_event->data.error_code);
    }
}

I suspect you get APP_UART_COMMUNICATION_ERROR so you should check the value in p_event->data.error_communication and compare it to the ERRORSRC register to get a hint of what is wrong. When you are in the event handler you should also check what sensor you are communicating with at that time to figure out where the error stems from.

RE: NRF51822 UART hangs and requires power cycle

srijan12 — Wed, 06 Dec 2017 06:44:08 GMT

It happens once in couple of days, and also not on each device. It seems to be framing issue. Also feels like overflow.

As of now, the uart_error_handle_A() does nothing. What should I write into it? Probably resetting all registers, clearing all buffers and restarting UART there should work.

RE: NRF51822 UART hangs and requires power cycle

MartinBL — Mon, 27 Nov 2017 14:14:16 GMT

I can't see anything wrong with using the library or FIFO.

Could it be that the UART experiences an error (framing or parity error for example) and ends up in an endless loop in an error handler somewhere? If this is the case it is strange that it doesn't help with a pin reset though. Have you used a debugger to check where the code is at when it hangs? Are you checking for, and gracefully handling, errors in your uart_error_handle_A() handler?