Issue with CR when using CLI and RTT logger

RE: Issue with CR when using CLI and RTT logger

Aviv Okon — Tue, 11 Aug 2020 09:00:04 GMT

I couldn't figure how to change nrf_fprintf_fmt, so I decided to change buffer_add instead as it was simpler

I've attached the code changes I made, and it seems that it works with NRF_FPRINTF_FLAG_AUTOMATIC_CR_ON_LF_ENABLED set to 1 for both CLI and RTT logs

so I believe this is the simplest solution to this situation, though let me know if you have a better one

static char prev_char = '\0';

static void buffer_add(nrf_fprintf_ctx_t * const p_ctx, char c)
{
#if NRF_MODULE_ENABLED(NRF_FPRINTF_FLAG_AUTOMATIC_CR_ON_LF)
    if (c == '\n'
		&& prev_char != '\r')
    {
        buffer_add(p_ctx, '\r');
    }

	prev_char = c;
#endif
    p_ctx->p_io_buffer[p_ctx->io_buffer_cnt++] = c;

    if (p_ctx->io_buffer_cnt >= p_ctx->io_buffer_size)
    {
        nrf_fprintf_buffer_flush(p_ctx);
    }
}

RE: Issue with CR when using CLI and RTT logger

Aviv Okon — Mon, 10 Aug 2020 14:08:27 GMT

Thanks for confirming this

I was somewhat afraid of having to modify something in the SDK, due to the nature of my project and how it is managed

I'll relay this, and see if the issue is considered severe enough to go through the process of changing the implementation in the SDK

I'll report back if I find any issues with this

thanks again

Aviv

RE: Issue with CR when using CLI and RTT logger

Einar Thorsrud — Mon, 10 Aug 2020 12:46:26 GMT

Hi Aviv,

I have reported this to the SDK developers.

The natural place to fix this would be in <SDK>\external\fprintf\nrf_fprintf_format.c. You could check if an \r has proceeded the \n, and only add it if it has not. As you can see it is not just a matter of changing buffer_add() though, as that function works on single characters. You either have to rewrite a bit more or consider a hack where you use a static variable to hold the previous character or similar.