[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 ...

This post is in response to a reader who asked about detecting mains electricity using a microcontroller. The easiest and safest way to detect mains electricity using a microcontroller is with an ...

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 ...

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 ...