Proffie monitoring/reporting on another circuit's battery?

Is it possible to have the Proffie v2.2 to monitor and react to another circuit’s battery, to use some pins on Proffie (other than the battery pins) to tap in to that other battery, and give audible warnings when that battery is lower <1.5v? The battery is a 3.7v (can go as high as 4.2v when fully charged).

Yes. If you don’t mind a little programming and a small amount of electronics.
Basically, you’ll need a voltage divder to bring the voltage down into the 0-3.3v range. (Two 10k resistors would work well.) The plug the result into Data1 or Data4 (which are the only pins that can do analogRead on a v2.2 proffieboard.)

Then it’s just a matter of doing something like:

  if (analogRead(pin) * 3.3 * 2 / 1024 < 1.5) {
     // play sound here

The two circuits needs to share a ground, or it won’t work of course.


Thank you, that’s perfect.