My electrical power meter has a pale yellow LED that flashes once for ever watt hour used. Inspired by power.labitat.dk, jespereklund.blogspot.com/2011/10/elmaler-overvagning-med-arduino.html and other projects, I set out to count the flashes with an Arduino and output some nice graphs showing my electricity consumption. I wanted to use an LDR (LDR’s on Amazon) to “see” the flashing LED […]