Problem with "saadc" example (nRF52840 PDK)

RE: Problem with "saadc" example (nRF52840 PDK)

ovrebekk — Mon, 12 Mar 2018 13:55:57 GMT

I am happy to help 🙂

Maxime — Mon, 12 Mar 2018 11:34:50 GMT

It works. Thank you very much!

Maxime — Fri, 09 Mar 2018 16:47:41 GMT

Thank you very much, I think you're right.

I will try and confirm the resolution of my problem.

ovrebekk — Fri, 09 Mar 2018 10:14:14 GMT

Hi Maxime

What is the supply voltage on the chip?

The voltage on any GPIO can not exceed VDD + 0.3V, as there are ESD protection diodes on the pins that will start conducting at this voltage.

Your results make sense if you have a VDD voltage of 1.8V, as you would expect the diodes to start conducting around 2.1V.

To solve this you would have to use a voltage divider externally, to make sure that the input voltage on the pin stays below VDD + 0.3V.

Best regards
Torbjørn Øvrebekk