topic Re: FRDM-MCXW71: how to read light sensor with Zephyr OS? in MCX Microcontrollers

FRDM-MCXW71: how to read light sensor with Zephyr OS?

gja — Fri, 20 Mar 2026 12:42:38 GMT

Hello,

I'm using the NXP FRDM-MCXW71 board with Zephyr OS.
The goal is to test the ADC functionality.

For this the samples\drivers\adc\adc_dt example is reworked by adapting the overlay file in the boards folder. The ADC pin is changed from CH2A to CH6B in the overlay file of the adc_dt example.

A clean build is made and flashed. However when reading the resulting measurement over UART this does not seem to reflect the reading of the light sensor.
An alternative test was done with ADC input CH5B that is connected to a digital switch. UART reading also don't reflect the switch position.

Any suggestions what changes are missing to fix the ADC readings?
Thanks.

Re: FRDM-MCXW71: how to read light sensor with Zephyr OS?

Christine_Li — Tue, 24 Mar 2026 10:13:11 GMT

Hi, @gja

May I ask what is your Zephyr version?

And you are using our SDK? How/where did you download the SDK? Can you please provide me the link you use?

If you can provide me more details to reproduce this issue, would be helpful to resolve it ASAP.

I plan to prepare the environment to reproduce this issue locally.

Best regards,

Christine.

Re: FRDM-MCXW71: how to read light sensor with Zephyr OS?

gja — Tue, 24 Mar 2026 10:16:21 GMT

Hello,

I had also posted this topic in the Zephyr section.
Maybe it is more convenient to discuss there.

FRDM-MCXW71: how to read light sensor with Zephyr OS?

Thanks.

Geert

Re: FRDM-MCXW71: how to read light sensor with Zephyr OS?

Christine_Li — Tue, 24 Mar 2026 10:21:01 GMT

Hi, @gja

Thanks for letting me know.

If it is same issue, I recommend close or cancel this one.

I see our colleague already supported you in your previous link.

In this way, can save your valuable communication time.

If it is different issue, we can keep discussing here.

Best regards,

Christine.