[Bill_B]

I measured current for an idle control system last year at under 1 amp. Later that same season I learned that the main circuit breaker has a resistance that is very close to providing 1mV per ampere of current going through it. I briefly considered making a small circuit that would allow the main program to monitor its own current use. The team wasn't interested, so I never pursued the legality of the simple wire connections. This wouldn't prevent you from making measures of a running machine while it is not in actual competition to find out what current is being drained. I may make a symbiotic NXT robot with data-logging to ride along just for curiosity's sake alone. If I knew more about arduinos I might be trying to use one of those to do it.