Shit, I'll bet you're right. If that's the case, wouldn't the control have to be considered part of the firearm and thus somehow connected? Or would a wireless connection suffice as a "connection"?
more or less if whatever is actuating the trigger can be reprogrammed to pull the trigger more than once, then it's a machine gun. So the only electronics found in triggers are generally present to create a safety that wont allow for a fire unless a condition is met, but the pull still has to be manual.
But somehow gattling gun trigger ad ons are legal and most of them have a convenient allen key on the knob that you can run a motor off of using a power drill, dremel, or even some spring wind up motors that have been sold by companies.