How to enable UART or RTT logging in examples?

[Al Bundy]

I have downloaded nRF5_SDK_12.2.0_f012efa and tried to test logging in examples but without success. Even if I compile an example where NRF_LOG_BACKEND_SERIAL_USES_UART 1 is enabled by default in sdk_config.h I do not get any logs on terminal. I have chmod 666 of /dev/ttyACM0 and set baudrate to default 115200 but still nothing. If I set NRF_LOG_BACKEND_SERIAL_USES_RTT instead of UART I also get nothing on JLinkRRTClient.

Is there anything else that needs to be configured? I compile for pca10028.

[Jørgen Holmefjord]

Hi,

It should be sufficient to set NRF_LOG_ENABLED 1 and either NRF_LOG_BACKEND_SERIAL_USES_UART 1 or NRF_LOG_BACKEND_SERIAL_USES_RTT 1. Note that if NRF_LOG_DEFERRED 1 is set, you also need to process the log buffer using NRF_LOG_PROCESS() or NRF_LOG_FLUSH()

Best regards,

Jørgen

[Navin]

Hello Jorgen,

I can't find NRF_LOG_BACKEND_SERIAL_USES_UART.

I get the error: undefined reference to `nrf_log_default_backends_init'

But I have enabled : #ifndef NRF_LOG_BACKEND_UART_ENABLED
                                 #define NRF_LOG_BACKEND_UART_ENABLED 1
                                 #endif

What could I possibly be missing?

[Jørgen Holmefjord]

Did you add the source file components\libraries\log\src\nrf_log_default_backends.c to your project? NRF_LOG_ENABLED also needs to be set.