Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

Vidar Berg — Fri, 25 Jul 2025 10:08:09 GMT

Update: turns out there's already an open PR in upstream Zephyr that attempts to address the issue: https://github.com/zephyrproject-rtos/zephyr/pull/92664

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

byte — Wed, 23 Jul 2025 15:38:17 GMT

Vidar,

Currently we are patching the SDK until we find a solution. Thanks for the update.

Rob

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

Vidar Berg — Wed, 23 Jul 2025 15:03:48 GMT

Hello Rob,

Both Edvin and Håkon are currently out of the office, so I haven’t had a chance to discuss the case with them yet. But I was able to replicate the same problem as you. And like you, I don’t see any way to prevent LFXO_CAP from being defined by making changes to Kconfig or the devicetree. I see Håkon already created a bug report in our internal bug tracker about this issue. I will add to this report that just deleting the lfxo node may not be sufficient.

Are you able to work around this issue for now by patching the SDK file(s) or by calling nrf_gpio_pin_control_select() again from the app?

Best regards,

Vidar

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

byte — Thu, 10 Jul 2025 16:15:12 GMT

Edvin,

Our app targets a modified board but here is a hello world app that you can see has the same issue. Look at the third page of the BuildSettings.pdf that I included. You will see that when you break in main the first two gpios are set to Peripheral mode instead of AppMCU even with the changes suggested above. If you can show me how to modify this hello world app make them usable then I should be able to make the same mod to our app.

Thanks, Rob

devzone.nordicsemi.com/.../6888.hello.zip

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

Edvin — Mon, 30 Jun 2025 21:31:18 GMT

Hello Rob,

Can you please upload the current application you are using (zip the application folder and drag and drop it here). Then I can see what you have done, and see if I can replicate your issue.

Best regards,

Edvin

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

byte — Wed, 25 Jun 2025 15:50:22 GMT

Håkon

Thanks for the reply,

Sorry, I don't understand your suggestion. I am missing something. Even if I delete the lfxo node from the dts, the #else part (/* LFXO config from legacy Kconfig */) in the code referenced in soc.c has no compile path that doesn't end up setting LFXO_CAP. So, no matter what I do with CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC I end up with the code that sets the pins to peripheral. Thanks so much for the help.

Rob

RE: Configuring PIN 0.00 and P0.01 as GPIO on NRF5340 with nrf connect sdk v3.0.2

Håkon Alseth — Mon, 16 Jun 2025 10:48:32 GMT

Hi,

[quote user=""]We upgraded our project to nrf connect sdk v3.0.2 from v2.9.0 and can no longer use pin 0.00 and pin 0.01 as gpio. [/quote]

Recently, the configuration of the external LFXO load caps has been moved to DTS.

This requires you then to remove the lfxo node:

/delete-node/ &lfxo;

And this is required to configure it to the internal 32k RC oscillator:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

Could you try this and see if this now works on your side?

There is an unfortunate mix of kconfig and device tree here, which I do acknowledge and will bring up internally.

Kind regards,

Håkon