NRF_LOG_INFO how to print log with string parameter

[vit bernatik]

If I receive some string from BLE and I want to log it to RTT how do I do it?

I tried this:

char str[] = "NameX";
NRF_LOG_INFO("dev nm: %s",str);

but it can not be compiled - error is:

......\main.c(1455): error: #167: argument of type "char *" is incompatible with parameter of type "uint32_t"

I assume there shale be something simple how to log string...

[ben38]

just cast to (uint32_t):

NRF_LOG_INFO("dev nm: %s",(uint32_t)str);

[FormerMember]

Another option is to use a pointer:

char *p_my_text = "Testing string";
	NRF_LOG_INFO(" %s \r\n", (uint32_t)p_my_text);

[Peter]

Also looks like NRF_LOG_INFO() stores a pointer to the string and not a copy of the string. So if the string that p_my_text points to is: on the stack you'll need to follow NRF_LOG_INFO() with NRF_LOG_FLUSH() before the string goes out of scope, or if the string is static call NRF_LOG_FLUSH() before the string is overwritten

[John1]

For anyone who looks this up in 2021+ the Nordic SDK now provides a neat method to improve the logging of strings:

char string_on_stack[] = "stack";
//nrf_log_push() copies the string into the logger buffer and returns address from the logger buffer
NRF_LOG_INFO("%s",NRF_LOG_PUSH(string_on_stack));

For more information see here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.1.0%2Flib_nrf_log.html