How to get log messages sent through UART, not RTT?

RE: How to get log messages sent through UART, not RTT?

Julio de Melo — Wed, 17 Mar 2021 17:33:18 GMT

Hi,

Thanks to both Awneil and Tesc. I will take a look in the threads and docs mentioned, as well as going through the init code in debug mode.

I did manage to get the code compiled, after adding a bunch of log-related source files. But still, no talk!

Regards,
Julio

RE: How to get log messages sent through UART, not RTT?

tesc — Wed, 17 Mar 2021 13:55:58 GMT

Hi,

nRF5 SDK for Mesh uses a different log module than the one used in nRF5 SDK. While it is possible to get logging over UART, it is a bit more involved, as the Mesh log module supports only RTT out-of-the-box.

You could have a look at the SDK Proximity coexistence example (which combines functionality from nRF5 SDK for Mesh and nRF5 SDK.)

There is an example of logging to UART provided in the answer to this thread: Adding UART code to the 'light switch server' project.

Regards,
Terje

RE: How to get log messages sent through UART, not RTT?

awneil — Wed, 17 Mar 2021 13:47:56 GMT

Personally, I've never had any trouble with it - it's just been a matter of making the appropriate RTT or UART setting in the sdk_config.h.

Did you start from an SDK example?

I find that stepping through the init code in the debugger is the easiest way to follow the decisions that are made in enabling the logs & choosing the interface ...

RE: How to get log messages sent through UART, not RTT?

Julio de Melo — Wed, 17 Mar 2021 13:16:10 GMT

Hi, Awneil,

Thanks for the tip. I went ahead and added a whole section regarding both macros. I copied it from another sdk_config.h file.

That did not solve the problem and looking further, I came across this post How to enable UART or RTT logging in examples? - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com), which mentions how to enable the UART for backend communication.

I am still struggling with compilation to make it work as any file that you add carries dependencies on header files, but I hope I will succeed.

Since this topic is frequent on the DevZone, isn't it time to write down a comprehensive guide on doing USB/UART on Nordic's devices?

Thanks,
Julio

RE: How to get log messages sent through UART, not RTT?

awneil — Tue, 16 Mar 2021 15:06:07 GMT

[quote userid="26678" url="~/f/nordic-q-a/72874/how-to-get-log-messages-sent-through-uart-not-rtt"]

NRF_LOG_BACKEND_RTT_ENABLED and NRF_LOG_BACKEND_UART_ENABLED, as being the way to enable either output to the log messages. But none of them are defined in the sdk_config.h file, so no help there. There is also mention to NRF_LOG_USES_RTT, but it also is absent.

[/quote]

That is a common complaint about the supplied sdk_config.h files:

https://devzone.nordicsemi.com/f/nordic-q-a/45366/missing-defines-in-generic-sdk_config-h

But that is where it should be defined.