Analog-to-digital converters, or ADCs, are somewhat monolithic devices for most users, a black box that you ask nicely for the value on its input, and receive a number in return. For most readers, ...

[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 Arduino ...