Problem Using UART2 on nRF9151 DK

RE: Problem Using UART2 on nRF9151 DK

WesC — Fri, 18 Jul 2025 14:06:37 GMT

I noticed that you disabled Interrupts in the prj.conf.

CONFIG_UART_2_INTERRUPT_DRIVEN=n
this should be set to Y

this is why you are failing in the irq_callback()

wes

RE: Problem Using UART2 on nRF9151 DK

WesC — Fri, 18 Jul 2025 14:02:04 GMT

I built from the echo_bot sample, but looking at the main.c for both the only difference is your PrintK statements in main.

RE: Problem Using UART2 on nRF9151 DK

sgordon291 — Thu, 17 Jul 2025 15:49:31 GMT

Thank you. I had done those things.

Did you build the main.c that I attached or create a new one from the sample?

Thanks!

Steve

RE: Problem Using UART2 on nRF9151 DK

WesC — Thu, 17 Jul 2025 15:01:13 GMT

I took the echo_bot sample and changed the binding to uart2 and added the overlay (identical to your overlay) and it ran without an issue. I am able to get the echo in a serial terminal.
make sure you are building for the nrf9151dk/nrf9151/ns and the overlay is included in the build

RE: Problem Using UART2 on nRF9151 DK

sgordon291 — Wed, 16 Jul 2025 23:07:28 GMT

Thanks for the comments. I made a mistake on the overlay when I did the first zip. I've attached a new zip with the (I believe) the proper overlay.devzone.nordicsemi.com/.../echo_5F00_bot_5F00_uart2_5F00_v2.zip

The program still has the same behavior and issue. It seems to never come back from the call

int ret = uart_irq_callback_user_data_set(uart_dev, serial_cb, NULL);

on line 87. The only thing that I've changed from the orig echo_bot is pointing 'uart_dev' to uart2 on line 24, and adding the overlay that enables uart2. Do you know what the issue might be?

On the question of ns vs a secure build, I only done ns builds because my understanding was that it was a simpler build, but I admittedly dont know much about this. At this point, security is not a concern, although it will be at some point. Is there a preference (ns or secure) that's the "better" one?

Thanks!

Steven Gordon

RE: Problem Using UART2 on nRF9151 DK

WesC — Tue, 15 Jul 2025 12:49:56 GMT

A few things I noticed on the code you shared.

Your overlay is for UART1 on pins P0.8 and P0.9.

these pins are used as Buttons on the nRF9151DK.

If you are targeting UART2 and open GPIO, you need to change the overlay to UART2 and select pins not used by the DK
Also you are building for the nRF9151DK_nrf9151 and not for nRF9151Dk_nrf9151_ns

are you looking to build for a complete secure application versus leveraging TF-M for security by separation