[Kevin Sevcik]

Let's cover the mechanical and electrical first. The pneumatic system has a high pressure side and a low pressure side. The high pressure side tops out at 120psi. It connects to the low pressure side through a regulator, which limits the pressure on the low side to 60psi.

The high pressure side is limited to 120psi by two things. First is a mechanical pressure relief that will start dumping air at around 125 psi. Second is a pressure switch. This is a normally closed switch that opens when the pressure reaches 120 psi. This switch is what lets your software know when you need to run the compressor more to get back up to 120 psi. It needs to be connected to the signal and ground pins of a digital input on your sidecar.

Programming is pretty easier. The relevant VIs are in WPI Robotics Library->Actuators->Compressor.

In your Begin.vi, you want to "Open" a compressor reference, then connect the created reference to the Start VI. Then the program will automatically monitor the pressure switch, and turn the compressor off and on with the Spike relay. Make sure you Do a Refnum Set to save the reference for later use.

In your Periodic Tasks VI, you need to drop the "WPI CompressorControlLoop" VI and pass it the save reference.

In your Finish VI, you need to get the compressor reference, pass it to a Stop VI, and then pass it to a Close VI. And then you're done.