I'm working on a lego conveyor belt system (for show) with 4 separate conveyor belts, each powered by a single M motor, each of which will be hooked up to a separate spot on the Sbrick. What would be really cool would be if a press of one button could activate all four motors in sequence (and deactivate them in the same order). Is this possible with just one button? I'm almost certain it could be done with 4 buttons (one for each motor) but that wouldn't be nearly as cool.
Maybe, assuming the timing thing can be done, a three button setup could be used (one for startup, one for looping, one for ending) to avoid the issue of seemingly not being able to loop part of a sequence.
Regardless... the main question I have is: What would be the best way to do this? Would rather not bang my head against a wall trying to do something that can't actually be done.