Redbear Nano - are I/O pins 5V tolerant?

It looks like Redbear Labs is no longer operational. I have one of their redbear nano nRF51822's. Does anyone know if these have 5V tolerant pins? How would I find out? Their github exists, but a lot of the original supplementary info is gone.


Arduino Nano 33 BLE only supports 3.3V I/Os and is NOT 5V tolerant so please make sure you are not directly connecting 5V signals to this board or it will be damaged.


2 Seconds to find this!

Come on, do some work for yourself. Not googling this before posting is just lazyness.

That link does not specify whether the pins are 5v tolerant (I’m not sure where you go to find the full datasheet with things like absolute maximum ratings), though the fact that they didn’t call it out suggests that they are not.

The fact that other nRF51822-based boards are not 5v tolerant, however, seems to be a pretty clear indication that it isn’t, though.