printf output is not displayed during debug

[Arie]

Dear Support,

 I’m working on uVision V5.25.2.0, using nRF5_SDK_15.0.0_a53641a.

My evaluation board is Rigado BMD-300.

Target: nrf52832_xxaa.

 I tried using the printf function while debugging, but its output is not displayed. I tested it in a few simple example projects (like Nordic\nRF5_SDK_15.0.0_a53641a\examples\peripheral\uart\).

 I did many efforts by searching in the Internet and applying different advices, but nothing helped.

 I need using this function to debug the signal processing algorithm. It means that I would be happy to get the simplest project, without uart and other peripherals.

 Thanks in advance,

 Arie Shlitner

[Susheel Nuguru]

The UART pin mapping in the SDK are mapped to a particular DK as per the project. I am not how the mapping of UART pins are done from your Rigado BMD-300 module onto the custom board. Look into the code of UART initialization in your project and check that the UART pin number matches the UART pin on your board.

[Arie]

Thanks,

I took the uart project as an example. I’m not interested specifically in uart or any other peripherals.

I just want my message, e.g. printf("Hello world!\r\n"); to be displayed in the Debug (printf) Viewer of the uVision.

[Susheel Nuguru]

You need to configure, the Trace port to be able to do that, I think. You can follow this post if you want to try it.

I do not see why you cannot use retarget.c file and redirect the log to the uart com port. It really simple to do. It is really really small benefit of getting the logs to Keil Debug (printf) viewer.

[Arie]

Thanks Aryan. I know this post and tried configuring the Trace before applying to support. This doesn’t work.

Surely, I can get output another way (and got it through the SEGGER J-Link RTT viewer), but I believe that such basic function as printf using native IDE should work (e.g. as in Code Composer Studio of TI).

[Susheel Nuguru]

native printf are never easy thing to support PC standard I/O for embedded solutions. They always remain tricky since embedded solutions does not have conventional IO capabilities. Neither do they have display. Hence all the prints needed to be rerouted from standard out to serial ports or debug ports.

[Arie]

Agree. Thanks very much.

[Arie]

After I haven’t found a solution in Google and didn’t receive an answer neither from the ARM nor from the Nordic support, I myself solved the problem, as follows:

In addition to known configuration, you must configure the TRACECONFIG register in your code:

		NRF_CLOCK->TRACECONFIG = (CLOCK_TRACECONFIG_TRACEMUX_Parallel << CLOCK_TRACECONFIG_TRACEMUX_Pos) |
		(CLOCK_TRACECONFIG_TRACEPORTSPEED_32MHz << CLOCK_TRACECONFIG_TRACEPORTSPEED_Pos); 

Enjoy!