My team uses an off-board compressor that we use to charge pneumatics before every match. Its connector the VRM and we uses Anderson to connect the two when needed. Recently we have been trying to test new code and let our new drivers practice, so we needed to use both the pneumatic gear shifter and the pneumatic coinslot. I have re-done the wiring on the VRM, the pressure switch, and the compressor, and I have also checked that the ball valve we use to seal the system is open when charging. The regulator and the pressure switch both read 0.
Question: Are you wired for R93C (using a PCM to control everything) or R93D (sensor to RoboRio to Spike)?
My team did a similar thing with the compressor this year and had issues with the anderson connector being loose. Try pushing the wires in the connectors with a screwdriver.
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Okay so the VRM --> Compressor for power, then the Pressure Switch on our release valve is set to cut the charging at 120psi
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OK… Where is the pressure switch wired to and read from? The PCM or the RoboRIO?
Assuming it’s the PCM (Pneumatics Control Module), you also need to check the connections on that: CAN for one. If it’s not in the CAN bus, there’s a problem. Note that the PCM is not the VRM (though they may look similar); if the pressure switch is wired into the VRM that’s the problem right there.
Wait, you’re using the VRM (AM link)? This is a) not legal and b) not sufficient to power your compressor. The VRM has a max draw (on a single channel) of 2A. Your compressor (I’m assuming you’re using this one, but others are probably pretty similar) draws upwards of 7A.
What you need to do is connect your compressor and pressure switch to your PCM (Pneumatic Control Module). Make sure this is hooked up to CAN (the green and yellow wires) and you initialize at least one Solenoid in your code.
My bad it was the PCM, excuse me, they look pretty similar
Things to check:
–CAN connected to PCM
–Robot ON and ENABLED when you want to fill the system
Also, the easy way to tell if the compressor is running: It’s noisy. Doesn’t matter what the gauges say, if the compressor isn’t noisy it isn’t running.
Wow a lot of basic questions about pneumatics in a short time span!
Check out the PCM User Guide, particularly pages 17 through 19 which are specifically about troubleshooting a compressor that won’t turn on. If you get through that (or part of it) and get stuck, you can use this as a basis for a much more specific question we can help you with.
I believe that you have to plug the compressor into the PCM. It looks a lot like the VRM but has specific connectors for the compressor, pressure switch, and solenoids. There is a weidmuller connector on the PCM labeled “Compressor Out” and that is where you will need to plug in the compressor for it to be controlled to maintain pressure.
Also need to check your PCM ID on the CAN and make sure it corresponds to what is in the code. Default constructor assumes an ID (0, I believe). If your PCM has a different ID, you need to use the constructor where you specify its ID.
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