[Isaac501]

Originally Posted by hyperdude

I'm no robot programmer, but I am pretty sure that you need to program the compressor to shut off when the pressure gets up to 120psi (when the relief valve opens). There's no way for the pneumatics system to "know" when it's at a certain pressure.

Now if you've already got this programmed, then you might want to post the code so someone can help you.

This is incorrect. There is a pressure switch that (if properly calibrated) will signal when the pressure is at 120 PSI. wpilib has code which turns off the compressor when this signal is received. The compressor requires no intervention past properly wiring it and instantiating and start()ing.