NRF52832 physical pin analogRead

[MikeLemon]

Hello,

I'm trying to read an ADC value from a sensor(for POC I'll be using a pot wired to 3.3V VDD and GND) but all the examples I found only demonstrated reading the internal VDD with the 0.6V reference:

for example(simplest code I found):

github.com/.../main.c

and nothing with the VDD reference and an actual physical pin....

does anybody has an idea were can you get such an example or at least how should the example code be modified to work with say pin "P0.04" sins I'm quite a noobie?

Thanks for your time.

[Matt]

Have you looked into the saadc example in ~\nRF5_SDK_12.2.0_f012efa\examples\peripheral\saadc\main.c ?

[MikeLemon]

Yes I did quite scary for a beginner like me just trying to get a reading in relation to ground but still didn't see any relation to the physical pin 0.02 in the code .

[Matt]

Don't understand your response here. Are you saying the module you are sampling does not share the same GND as the nRF52832? Are these two not on the same PCB?

[MikeLemon]

No I just don't understand how this example work like where is the line of code that configs P0.02 pin to analog channel 1 anyways when debugging and shorting the pin to ground the precise result values remains unchanged (2.8 around) instead of the expected 0V

[Matt]

Try nrf_drv_saadc_channel_init(); there is also documentation in the SAADC section in the infocenter.