printf problem after startup of device

RE: printf problem after startup of device

Simon — Fri, 05 Jul 2019 20:06:20 GMT

[quote user=""]After start-up every time the first printf miss to print something. After that, it works properly.[/quote]

Are you calling printf() before uart_init()? That will not work. However, then the program should hang, like explained here, and it doesn't seem that's your case.

Could you share your project or a minimal project that demonstrates this behavior, then I can try to reproduce it. I can make the case private if you would like so.

Best regards,

Simon

RE: printf problem after startup of device

awneil — Thu, 04 Jul 2019 15:31:36 GMT

[quote userid="75374" url="~/f/nordic-q-a/49382/printf-problem-after-startup-of-device/196642"]suggest another way[/quote]

i suggest that you use a terminal or similar to see what is actually being sent.

Best to use something that shows the raw hex - so that you can see if stuff is getting corrupted.

RE: printf problem after startup of device

predragn — Thu, 04 Jul 2019 15:15:06 GMT

I use while (app_uart_get(&cr) != NRF_SUCCESS): to receive the message character by character, (meanwhile parse it). I have led indication to tell me the message is received, and so on. So I don't think the problem is in receiving but if you think the problem is in approach that i showed (i took this approach from the example) you can suggest another way. Except these i have an Uart error handler. Imagine https://infocenter.nordicsemi.com/index.jsp just without the loopback test and with logic for receiving and parsing the message character by character.

RE: printf problem after startup of device

awneil — Thu, 04 Jul 2019 15:01:03 GMT

[quote userid="75374" url="~/f/nordic-q-a/49382/printf-problem-after-startup-of-device/196632"]I send some command, wait for the answer that never happen that time.[/quote]

So how do you know whether the problem is in the sending or the receiving?

Or both?

RE: printf problem after startup of device

predragn — Thu, 04 Jul 2019 14:55:14 GMT

I wasn't absolutely precise about that - thing is: I have implemented some commands that come over the same uart where the printf flushes it's stream. Now the problem is after startup - I send some command, wait for the answer that never happen that time. Next time I send same command i have expected answer sent back. No power off s between steps.

There is one more thing weird about that (take a look the code bellow): Explained situation happens when have some led togglings (based on nrf_delay_ms()); If put the printf above the Master_UsrLedsToggle() printf sends character stream normaly. If situation is that I have printf bellow the toggling, i don't get the answer after startup.

if(CMD_BUFF[2]=='U'){
								Master_UsrLedsToggle();
								printf("LEDU ENTER\n");
						}

RE: printf problem after startup of device

awneil — Thu, 04 Jul 2019 14:31:07 GMT

[quote userid="75374" url="~/f/nordic-q-a/49382/printf-problem-after-startup-of-device"]the first printf miss to print something[/quote]

What, exactly, do you mean by that?