I have a 100A 75mv shunt across the negative terminal on the leisure battery in my campervan, and a simple digital ammeter which measures current flowing out of the battery. I also have a switch installed which flips the polarity on the meter and allows me to measure current flowing into the battery - from the alternator when the engine is running, a solar panel or mains hookup when parked up.
Could this be achieved using the Arduino (and preferably my existing shunt) without the need for a polarity reversing switch? I'd like to throw up a value on an LCD display which automatically moves from positive to negative as current flows into or out of the 12v battery.
Thanks in advance!