[Trent M. Wyatt]’s CPUVolt library provides a fast way to measure voltage using no external components, and no I/O pin. It only applies to certain microcontrollers, but he provides example Ar… ...

We got it running on an Arduino Leonardo the quickest, because it has support for Serial1(). Don’t be discouraged by these glitches in this rev 0 deployment — [Eric] has really made quite a ...