SEGGER_RTT works but NRF_LOG not

[schef]

Hi, can you help me out please: I have followed devzone.nordicsemi.com/.../ and have configured as it shows.

But NRF_LOG_INFO does not work however SEGGER_RTT_printf does. What should i do? Thanks

[Jørgen Holmefjord]

Which SDK version are you using? Have you set NRF_LOG_ENABLED and NRF_LOG_BACKEND_SERIAL_USES_RTT? Are you using NRF_LOG_DEFERRED? If you are, you need to call NRF_LOG_FLUSH() to process the log buffer.

[NickH]

I have a similar issue with SDK15.3.  I managed to get the NRF_LOG working on one project after reading all the forum posts but when I try on a virgin instance of ble_app_multilink_central using this knowledge, logging does not work.

 - I have compiled and run debug config

 - Project settings are debug level 3

 - NRF_LOG_ENABLED, NRF_LOG_BACKEND_RTT_ENABLED are enabled and NRF_LOG_DEFERRED disabled in sdk_config.h via CMSIS configurator.  NRF_LOG_BACKEND_UART_ENABLED also disabled

No log messages are printed at any level.  Printf works fine....

[Jørgen Holmefjord]

I just tested the ble_app_multilink_central example. UART logging works out of the box, setting NRF_LOG_BACKEND_RTT_ENABLED to 1 enables output in RTT viewer as well. Please try with a completely fresh copy of the entire SDK.

[NickH]

Thanks for the reply - I tried what you suggested and ran ble_app_multilink_central from a fresh copy of the SDK (nRF5_SDK_15.3.0_59ac345) and looking at the output via the Segger Studio after enabling NRF_LOG_BACKEND_RTT_ENABLED via CMSIS, saving, cleaning and rebuilding and I still see no output.  Are there any other checks I can do?  My other project still prints debug via RTT fine but I can't see what the difference is...

Nick

[Jørgen Holmefjord]

Are you sure that the config actually got set? CMSIS config wizard seems to require you to switch to view another config before saving for the value to be updated. I would recommend that you open the sdk_config.h file in a text editor and make sure the config is set there.

[NickH]

I agree that sometimes this can happen but I have confirmed settings are OK for what I understand is required:

NRF_LOG_ENABLED 1

NRF_LOG_BACKEND_RTT_ENABLED 1

NRF_LOG_DEFERRED 0 

NRF_LOG_BACKEND_UART_ENABLED 0

I have tried other sample projects and none of them seem to work OOTB either although I did manage to get one working which is what I have been using as my base - wish I could remember what I did...

[Jørgen Holmefjord]

You are able to debug the application in SES? Which version of SES and J-Link are you using? I'm not sure what can cause issues if you are not able to see the logs with a clean SDK. As I said, I tested this and it worked well.