It’s basically a current monitor based off an AtMEGA328, which I am programming using the Arduino bootloader. Really quite simple stuff :) It’ll show the battery voltage, and current consumption on a 16×2 lcd. And from that, I can calculate the power, too.
The current measuring is done by a 100A “HASS 100-S” current transducer. The analog signal processing is done by the Microchip Op-amp. The voltage measuring is done by a simple voltage divider on the supply rail. Would have been better with 4-wire measuring, but I was lazy, and the voltage drop across the wires is minimal :)
Via the forum.