A multimeter is an easy prospect, right? Back in the day you could make one fairly easily with a decent panel meter and a set of precision resistors, and now a digital one can be had for throwaway ...

Our hacker [John Duffy] wrote in to let us know about a video he put together to explain the design of his open-source multimeter, the HydraMeter. If you’re interested in how the circuitry for a ...