Issue with CR when using CLI and RTT logger

[Aviv Okon]

Hi

I have a project that uses several protocols, including UART and USB CLI

As such, I had to move the nRF logger to work on RTT, so that everything could work properly

My issue is that if I get the RTT logger working, my CLI printing break (they are going diagonally instead of as new lines)

I investigated and found the issue was related to the define NRF_FPRINTF_FLAG_AUTOMATIC_CR_ON_LF_ENABLED in sdk_config.h

according to nrf_log not working on SES, I need to set the define to 0 for RTT prints to work correctly

however, according to cli new line problem, I need to set the define to 1 for CLI prints to look correct

I tried changing the syntax of my CLI prints, but I think some of the formatting is tied to the CLI functions in the SDK, which I don't want to change

Is there any way to get both a functioning RTT logger in SES, as well as organized prints in my CLI interface, in the same project?

Any and all help will be appreciated

Thanks in advance

Aviv

[Einar Thorsrud]

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.

[Aviv Okon]

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

[Aviv Okon]

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);
    }
}