[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 ...

When working on simple DC systems, a small low-cost multimeter from the hardware store will get the job done well enough. Often they have the capability for measuring AC, but this is where cheap ...

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 ...