nrf_log from debug port

inya_lake gravatar image

asked 2017-04-21 13:56:58 +0200

Hi, I'm using nrf51dk board and nrf_log came out correctly on my RTT terminal with built in module. After that I use debug port (P20) to program to my custom module. I've vdd, gnd, swdio and swdclk connected to my custom module and everything functions properly. However, my nrf_logs are not coming out to my terminal. Does logger module uses uart lines? If so, is there a way I can get logs another way? Meaning all I want to connect to my module is using 4 lines (vdd,gnd, swdio and swdclk). Or my settings in my sdk_config is incorrect. Thanks

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endnode gravatar image

answered 2017-04-21 18:01:34 +0200

updated 2017-04-21 18:01:48 +0200

From what I see here you need 5 additional dedicated lines for Tracing functionality which seems not accessible on P20 debug port of nRF5x DK board with SEGGER J-Link OB. So I'm afraid you cannot use it for Tracing on external nRF52 chip, you would need some more expensive debugging HW probe...

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I was trying to verify my answer by looking to nRF52 DK schematics and PCB layout but I guess it's true. This tutorial suggests that SEGGER debuggers need these additional lines. I see that IMCU_xxx lines on nRF52 DK are accessible but only through special 10-pin needle connector (not having name printed on PCB, it's close to SEGGER J-Link Atmel MCU, on the way to nRF52832 chip...). So in the end you might be able to combine that with P20/P19 ports but I don't see the way how to do it easily.

endnode ( 2017-04-21 18:17:04 +0200 )editconvert to answer

And this page describes which GPIO lines are having TRACE function.

endnode ( 2017-04-21 18:18:38 +0200 )editconvert to answer

thank you for your answer. It was very helpful.

inya_lake ( 2017-04-21 18:36:42 +0200 )editconvert to answer
inya_lake gravatar image

answered 2017-04-21 18:08:59 +0200

zishiquan gravatar image

updated 2017-04-27 05:25:38 +0200

thank you for your answer. I've Segger jlink stand alone programmer and maybe I can use it to get debug logs correct.

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Asked: 2017-04-21 13:56:58 +0200

Seen: 117 times

Last updated: Apr 21