RTT logging: no output in SDK 11?

RE: RTT logging: no output in SDK 11?

Eliot Stock — Wed, 19 Apr 2017 15:10:37 GMT

Coming back to my own question ages later, another thing that caught me out was that the default logging level in the sdk_config.h I was using was 3 (info) and I had been testing logging with NRF_LOG_DEBUG() (level 4). Maybe this'll help someone else in the same situation.

RE: RTT logging: no output in SDK 11?

Eliot Stock — Fri, 27 May 2016 19:58:31 GMT

Thank you so much! This has been killing me.

RE: RTT logging: no output in SDK 11?

Aaron — Fri, 27 May 2016 19:30:58 GMT

I am also having trouble with RTT porting an existing app to v11. In my case it seems I'm running into the "In some cases J-Link cannot locate the RTT buffer in the known RAM region." issue from www.segger.com/jlink-rtt.html. I ran

exec SetRTTAddr 20002c40

from JLinkExe, where 20002c40 was the location of _SEGGER_RTT in the _build/nrf51822_xxaa_s130.map file, and RTT started working. The FAQ linked says that

eval "monitor exec SetRTTAddr %p", &_SEGGER_RTT

should work from gdb but I haven't tried it. Trying to get RTT working so that I can avoid gdb in the first place.

RE: RTT logging: no output in SDK 11?

Vidar Berg — Fri, 27 May 2016 12:14:27 GMT

Hi,

Please try with a clean copy of one of the standard BLE examples from the SDK and add the LOG macros in the main loop:

int main()
{
     // Initialize.
     NRF_LOG_INIT();
     ....

     // Start execution.
     ...... 

// Enter main loop.
for (;;)
{
    NRF_LOG("print something");
}

And make sure to add -DNRF_LOG_USES_RTT=1 compiler flags before building. This worked on my OSX setup using J-link V.5.12f. If it does work you could just copy the implementation into your project.