Cannot get UART00 to function

RE: Cannot get UART00 to function

cemile nur damnali — Mon, 02 Mar 2026 06:18:42 GMT

Thank you so much have a nice day!

RE: Cannot get UART00 to function

Nick_RA — Sun, 01 Mar 2026 20:37:08 GMT

See above... I had CONFIG_UART_CONSOLE set to "n". But there was a separate problem allowing uart00, see this ticket Afterwards it was OK.

RE: Cannot get UART00 to function

cemile nur damnali — Fri, 27 Feb 2026 12:34:27 GMT

Hi, I am facing the same exact problem. How did you solve it because i am going to lose my mind over this topic.

RE: Cannot get UART00 to function

Nick_RA — Thu, 21 Aug 2025 10:21:47 GMT

It turned out to be something painfully stupid...

I tried a fresh build using the 54L15DK, with my DTS as an overlay and it worked. So I checked the generated files as you suggested and found.... CONFIG_UART_CONSOLE=n

It's set in my project and obviously in the DK config, but was missing because I switched to using the simple hello_world sample to get the hardware and DTS working. I can't quite see why it should be needed anyway as the "chosen" property tells Zephyr to use the uart for console, but there you go.

Anyway it's working now, thanks for your help.

RE: Cannot get UART00 to function

Kenneth — Wed, 20 Aug 2025 20:57:24 GMT

I see now he use other pins for uart00, so maybe not as useful as I first thought.

But I am not aware of any specific problems here, it should be straight forward.

Can you share zephyr.dts and .config from build folder? Maybe you can look at the uart00 for additional configuration there.

Kenneth

RE: Cannot get UART00 to function

Nick_RA — Wed, 20 Aug 2025 19:20:56 GMT

It doesn't seem to...

Unless I'm missing the point, that's referring to using uart20 on P2. I'm using uart00 so there should be no crossing power domains etc.

I tried adding nrfx_power_constlat_mode_request(); / nrfx_power_constlat_mode_free(); anyway but it didn't make any difference. Also I'm not getting garbled text, there is no activity on the pin whatsoever.

RE: Cannot get UART00 to function

Kenneth — Wed, 20 Aug 2025 18:26:43 GMT

Maybe this post can help:
When using pin p2 for uart20, garbled text is printed.

Kenneth

RE: Cannot get UART00 to function

Nick_RA — Wed, 20 Aug 2025 11:15:17 GMT

I heard you the first time 🙂

Yes, as already mentioned above I reconfigured the jumpers

Cut SB11-16

Bridge SB17-22

Also, as I mentioned, this is for a custom PCB, but to troubleshoot and eliminate the hardware I switched to using the DK (but I am using my custom DTS)

RE: Cannot get UART00 to function

Kenneth — Wed, 20 Aug 2025 11:07:39 GMT

Hi,

Are you using the DK? In that case, check out table 3 here:
https://docs.nordicsemi.com/bundle/ug_nrf54l15_dk/page/UG/nRF54L15_DK/hw_desription/connector_if.html
https://docs.nordicsemi.com/bundle/ug_nrf54l15_dk/page/UG/nRF54L15_DK/hw_desription/solder_bridge.html

Kenneth

RE: Cannot get UART00 to function

Kenneth — Wed, 20 Aug 2025 11:06:33 GMT

Hi,

Kenneth