Read UART input while using Logger Module

[Hieu]

I examine the Logger Module implementation a little and find out that the only way to get a character from UART is via the NRF_LOG_GETCHAR() macro, which is blocking.

I would like to receive bytes asynchronously and process them, both over UART and RTT. How could I do it with the Logger Module enable? Is using App UART library and other RTT API alongside the Logger Module an option?

Another question is, if I enable both UART and RTT for the Logger, which one will NRF_LOG_GETCHAR() get the character from? I did an SDK wide search could only trace back to nrf_log_getchar() in nrf_log_internal.h. I could not find its implementation anywhere.

[Jakub Rzeszutko]

I assume you are using SDK14.1 basing on question tag. In such case like yours I strongly recommend using CLI module instead of NRF_LOG_GETCHAR() macro. Beginning from SDK14 CLI can be configured as Logger backend. It will give you a lot of flexibility in regards to logs display like logs filtering and text analizyses (commands or text autocompletion).

Please familiarize with this example: sdk\nrf5\examples\peripheral\cli

You can run two independent instances of CLI one on RTT other on UART/UARTE.

More information can be found in CLI documentation: infocenter.nordicsemi.com/.../lib_cli.html

or these two blogposts:

devzone.nordicsemi.com/.../

devzone.nordicsemi.com/.../

[Hieu]

I disabled UART as Logger Backend and setup app_uart_fifo for the time being. But I will definitely try to use the CLI module once I am done with my current task. Thanks for the answer.

[Keith Brafford]

BTW the SDK 14.2 cli example builds to 264 bytes larger than you can compile with the free version of Keil.  That makes it harder to evaluate. 

[Sigurd]

Hi Keith,

You can also use Segger Embedded Studio IDE to evaluate, it has no code limit.

Segger Embedded Studio can be used for commercial and non-commercial purpose with Nordic Semiconductor devices free of charge. See this article for more information about that.