[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 ...

Denis Hennessy recently encountered a problem we've all faced: he needed some AAs for a battery-eating gizmo, and he was overwhelmed by the choices available. Ignoring the shiny packaging and its ...