Using second microcontroller for datalogging

wvmarle:
Nonsense. I'm powering mine always from USB (5V) and there are 3.3V versions around as well. No need to supply that high a voltage - unless you like to stress its tiny built-in regulator of course.

Hey man, don't shoot the messenger. I'm just referencing the product list https://www.arduino.cc/en/Products/Compare

https://store.arduino.cc/usa/arduino-mini-05