Chief Delphi - Compressor won't shut off at certain PSI

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Compressor won't shut off at certain PSI

We just got our compressor working today that's attached with a pressure switch and a relay. Our compressor turns on when we start the robot on teleoperated mode but it doesn't turn off when we reach a PSI of above 125 (factory default).
Our spike is connected up to slot 7 in the relay on the digital sidecar, and our pressure switch is connected to slot 3 on our digital I/O. Everything works fine except that the signal to the pressure switch isn't being received so it's not opening and closing the circuit. We aren't quite sure what the problem is, but here's my code dealing with the compressor, and the relay.

tldr;We are able to manually start and stop the compressor with a button on our joystick, but not have it work automatically via the pressure switch.

Code:

public class RobotTemplate extends SimpleRobot {    

        

    //Check robot for right numbers    

    Joystick controller = new Joystick(2);           



    Compressor mainCompressor = new Compressor(7,3); // Relay, Digital IO    

   

    Relay spike = new Relay(7);

        

    public void roboinit(){   

        mainCompressor.start();

        System.out.println("Robot Initiated:");

    }  



    public void operatorControl()

    {   

        System.out.println("Telop Activated:");

        mainCompressor.start();       

        while (true){                           

        

        //==================== Spike ====================//

        spike.set(Relay.Value.kOn);

        spike.set(Relay.Value.kForward);

       /* if(controller.getRawButton(5)){  

            

            //spike.set(Relay.Value.kForward);

            

        }

        else if(controller.getRawButton(6)){

            spike.set(Relay.Value.kReverse);

        }

        else{

            spike.set(Relay.Value.kOff);

        }

        */

        }

    }

Re: Compressor won't shut off at certain PSI

Check the javadocs (they can be found under your home directory at sunspotfrcsdk/doc/javadoc/index.html) for the Compressor class. I'm pretty sure the constructor expects the two parameters to be the "pressure switch digital input channel" followed by the "spike relay channel". I think you have them reversed in your code. Try:

Code:

Compressor mainCompressor = new Compressor(3, 7); // DIO, Relay

Also, once you start the Compressor object, you should not manipulate the spike by hand. The while loop you show in your teleop code continually attempts to turn the compressor on. I would recommend that your remove the spike entirely from your class (comment it out for now). I suspect allocating it will cause a stack trace once you change the order of the parameters to the compressor (the WPI library won't typically let a Relay be constructed more than once with the same channel ID).

You might also want to put the state of the pressure switch out to the dashboard periodically so you can confirm that it is working:

Code:

public void operatorControl() {   

        System.out.println("Telop Activated:");

        mainCompressor.start();       

        while (isOperatorControl()) {

           // Add your code



           // Periodically update dashboard values

           updateDashboard();



           // Optional short sleep so main loop is not going full out

           Timer.delay(.01)                           

        }

}



// Time of last dashboard update

private double _LastUpdate = 0;



public void updateDashboard() {

    double now = Timer.getFPGATimestamp();

    // Don't need to update the dashboard values more than 5 times a second

    if ((now - _LastUpdate) >= 0.2) {

       SmartDashboard.putBoolean("Full Pressure", compressorMain.getPressureSwitchValue());

       // Add other smart dashboard things to monitor here

    }

}

Hope that helps,
Paul