Murata announced the compact DMR20-10-DCM “nanoMeter” self-powered auto-ranging DC voltmeter designed for mounting in an industry-standard “oiltight” 30 and 30.5 mm / 1.2 inch round panel cutout.

Here is a useful circuit for Arduino lovers and experimenters. It is a simple digital voltmeter, which can safely measure input dc voltages in 0 to 30V range. The Arduino board can be powered from a ...