[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… ...

Not long after [CulinarilySpeaking] got into the Arduino game, he began to want more IO pins and a larger program space for more ambitious projects. This, of course, led him down the path towards t… ...