NCS/Zephyr - Dynamically modifying pin's function at runtime

RE: NCS/Zephyr - Dynamically modifying pin's function at runtime

Maria Gilje — Thu, 02 Oct 2025 13:59:43 GMT

Hello,

In general, one peripheral can not be driven by both nrfx and Zephyr drivers. So Zephyr logging on an nrfx driven UART instance will not work, to my knowledge.

Best regards,

Maria

RE: NCS/Zephyr - Dynamically modifying pin's function at runtime

yanbingyu — Wed, 01 Oct 2025 18:38:22 GMT

Maria Gilje Even though this post was from 2 years ago, I still want to ask a follow up question, hope you can help.

When using the nrfx UART driver, can the Zephyr log functions output to the UART port driven by the nrfx driver? I.e. log messages can be viewed on that UART port?

Thanks!

RE: NCS/Zephyr - Dynamically modifying pin's function at runtime

Maria Gilje — Fri, 29 Dec 2023 07:18:05 GMT

Sorry about the delay.

Your devicetree can stay as it was.

[quote user="eyalasko"]What *.h files should be included (I tried to #include <nrf_gpio.h> but got a build error)[/quote]

Did you look at the samples I linked in my previous answers? Here is a link to the 2.5.0 versions on github as well: nrfx prs and nrfx use

[quote user="eyalasko"]be advised the NRFX UARTE doumentation mentions tx_cache/rx_cache which are not available in nrfx_uarte.h...[/quote]

tx_cache and rx_cache are in the main branch of NCS but not in any of the currently tagged releases (latest is v2.5.1).

Best regards,

Maria

RE: NCS/Zephyr - Dynamically modifying pin's function at runtime

eyalasko — Tue, 19 Dec 2023 15:33:31 GMT

Thanks for your prompt response.

If going for NRFX drivers as you advised, should I remove all references to this UARTE from the devicetree as well (or would it suffice just not to use it in the Zephyr way?)

What *.h files should be included (I tried to #include <nrf_gpio.h> but got a build error)

btw,

be advised the NRFX UARTE doumentation mentions tx_cache/rx_cache which are not available in nrfx_uarte.h...

RE: NCS/Zephyr - Dynamically modifying pin's function at runtime

Maria Gilje — Tue, 19 Dec 2023 14:43:45 GMT

Hello,

Zephyr offers Dynamic pin control now, but it is only meant to be used for uninitialized devices. The recommendation is to use only in early boot stages. From your description it seems the Dynamic pin control is not a good match, but I wanted to include it for completeness.

A possibility is to use nrfx drivers instead of Zephyr drivers. There is an nrfx driver and HAL for UART and HAL for GPIO. Note that when assigning pins with nrfx you can't use them with Zephyr. This option requires that you have full control over what you are doing, though.

Some examples using the nrfx drivers and HAL is the nrfx peripheral resource sharing example and nrfx use example.

Best regards,

Maria