UART transmission seems to be working weirdly

RE: UART transmission seems to be working weirdly

morpho — Sat, 25 Sep 2021 04:42:02 GMT

Well, the issue certainly was with the flags.

- First issue: `while (txdRdyEvnt); `isn't taking into account the updated value.

- Second: the following flow and disabling TxdRdy interrupt flag did the trick!

void Uart::TxBlocking(uint8_t *buffer, size_t bytesToSend)
{
    for (uint8_t idx = 0; idx < bytesToSend; idx++)
    {   
        setNrfEvent(NRF_UART_EVENT_TXDRDY, 0);
        TxByte(buffer[idx]);
        while (getNrfEventStatus(NRF_UART_EVENT_TXDRDY) == 0);
    }
}

RE: UART transmission seems to be working weirdly

Simonr — Fri, 24 Sep 2021 05:47:47 GMT

What pins are you using for UART transmissions? Is there a way to reproduce this on an nRF52 DK or do you only see it on a custom board?

Best regards,

Simon

RE: UART transmission seems to be working weirdly

morpho — Wed, 22 Sep 2021 23:44:32 GMT

it literally just prints "?". I am running at 115200. I am trying to narrow down the potential cause(s) here...

RE: UART transmission seems to be working weirdly

Simonr — Wed, 22 Sep 2021 10:11:49 GMT

Not that I can see, no. Are the characters that are printed actual question marks "?" or just jibberish (broken characters and such)? What baud rate are you trying to print on exactly? It could be that the device isn't able to print correctly when running "full speed" at too high of a baud rate for instance and is only able to print one character successfully at a time (which is why the breakpoints succeed).

Best regards,

Simon

RE: UART transmission seems to be working weirdly

morpho — Tue, 21 Sep 2021 04:47:29 GMT

Again, if baud rates were different, I probably wouldn't have seen the expected output with the breakpoints set. Same reasoning with ASCII conversion. Do you see any issues with the way I'm using the flags?

RE: UART transmission seems to be working weirdly

Simonr — Mon, 20 Sep 2021 12:47:53 GMT

The first thing that comes to mind is that you might be using different baud rates in the application and terminal which would cause jibberish data. Alternatively, are there some problems with the ASCII conversion perhaps.

Best regards,

Simon