Add pressure sensor

src/main/java/frc/robot/Robot.java

@@ -1,10 +1,12 @@
 package frc.robot;
 
+import edu.wpi.first.wpilibj.Compressor;
 import edu.wpi.first.wpilibj.TimedRobot;
 import edu.wpi.first.wpilibj.command.Command;
 import edu.wpi.first.wpilibj.command.Scheduler;
 import edu.wpi.first.wpilibj.smartdashboard.SendableChooser;
 import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;
+import frc.robot.sensors.PressureSensor;
 import frc.robot.subsystems.Drivetrain;
 
 /**
@@ -27,11 +29,13 @@ public void robotInit() {
         // HACK: Singletons don't like working unless they're grabbed before use.
         OI.getInstance();
         Drivetrain.getInstance();
+        // Start compressor
+        new Compressor().start();
         // chooser.setDefaultOption("Default Auto", new ExampleCommand());
         // chooser.addOption("My Auto", new MyAutoCommand());
         SmartDashboard.putData("Auto mode", chooser);
 
-        String[] displays = new String[]{"Display Drivetrain data?", "Display navX data?"};
+        String[] displays = new String[]{"Display Drivetrain data?", "Display navX data?", "Display pressure?"};
         for (String display : displays) {
             if (!SmartDashboard.containsKey(display)) {
                 SmartDashboard.putBoolean(display, false);
@@ -50,6 +54,9 @@ public void robotInit() {
      */
     @Override
     public void robotPeriodic() {
+        if (SmartDashboard.getBoolean("Display pressure?", false)) {
+            SmartDashboard.putNumber("Pnuematic pressure", PressureSensor.getInstance().getPressure());
+        }
     }
 
     /**

src/main/java/frc/robot/RobotMap.java

@@ -40,4 +40,6 @@ public class DRIVETRAIN {
 
     public static final int LEFT_JOY = 0;
     public static final int RIGHT_JOY = 1;
+
+    public static final int PRESSURE_SENSOR_PORT = 0;
 }

src/main/java/frc/robot/sensors/PressureSensor.java

@@ -0,0 +1,36 @@
+package frc.robot.sensors;
+
+import edu.wpi.first.wpilibj.AnalogInput;
+import frc.robot.RobotMap;
+
+public class PressureSensor {
+    private static final PressureSensor INSTANCE = new PressureSensor(RobotMap.PRESSURE_SENSOR_PORT);
+
+    private AnalogInput ai;
+    /**
+     * The voltage into the sensor.
+     */
+    private static final double VCC = 5.0;
+
+    public PressureSensor(int inputPin) {
+        this.ai = new AnalogInput(inputPin);
+    }
+
+    private double getVoltageOut() {
+        return ai.getVoltage();
+    }
+
+    /**
+     * Return the pressure, in PSI. Has a tolerance of 1.5% according to REV.
+     *
+     * @return Measured pressure, in PSI.
+     * @see "http://www.revrobotics.com/content/docs/REV-11-1107-DS.pdf"
+     */
+    public double getPressure() {
+        return (250 * (this.getVoltageOut() / VCC)) - 25;
+    }
+
+    public static PressureSensor getInstance() {
+        return INSTANCE;
+    }
+}