Add PIDInterface for PIDController and CAN devices.

Added a PIDInterface for the PIDContrller, CANJaguar, and CANTalon to
inherit from.

Change-Id: I88d4943159476a44400009703db5e79d8cd4b5a9

wpilibj/wpilibJavaDevices/src/main/java/edu/wpi/first/wpilibj/CANJaguar.java

@@ -23,7 +23,7 @@ import edu.wpi.first.wpilibj.util.CheckedAllocationException;
  * Texas Instruments Jaguar Speed Controller as a CAN device.
  * @author Thomas Clark
  */
-public class CANJaguar implements MotorSafety, PIDOutput, CANSpeedController, LiveWindowSendable {
+public class CANJaguar implements MotorSafety, PIDOutput, PIDInterface, CANSpeedController, LiveWindowSendable {
 
 	public static final int kMaxMessageDataSize = 8;
 
@@ -304,6 +304,27 @@ public class CANJaguar implements MotorSafety, PIDOutput, CANSpeedController, Li
 		return m_value;
 	}
 
+  /**
+   * Equivalent to {@link #get()}.
+   */
+  @Override
+  public double getSetpoint() {
+    return get();
+  }
+
+  /**
+   * Get the difference between the setpoint and goal in closed loop modes.
+   *
+   * Outside of position and velocity modes the return value of getError()
+   * has relatively little meaning.
+   *
+   * @return The difference between the setpoint and the current position.
+   */
+  @Override
+  public double getError() {
+    return get() - getPosition();
+  }
+
 	/**
 	 * Sets the output set-point value.
 	 *
@@ -387,6 +408,20 @@ public class CANJaguar implements MotorSafety, PIDOutput, CANSpeedController, Li
 		set(value, (byte)0);
 	}
 
+  /**
+   * Equivalent to {@link #set(double)}. Implements PIDInterface.
+   */
+  @Override
+  public void setSetpoint(double value) {
+    set(value);
+  }
+
+  @Override
+  public void reset() {
+    set(m_value);
+    disableControl();
+  }
+
 	/**
 	* Check all unverified params and make sure they're equal to their local
 	* cached versions. If a value isn't available, it gets requested.  If a value
@@ -834,6 +869,11 @@ public class CANJaguar implements MotorSafety, PIDOutput, CANSpeedController, Li
 		disableControl();
 	}
 
+  // PIDInterface interface
+  public void enable() {
+    enableControl();
+  }
+
 	// PIDOutput interface
 	@Override
 	public void pidWrite(double output) {
@@ -1061,6 +1101,15 @@ public class CANJaguar implements MotorSafety, PIDOutput, CANSpeedController, Li
 		enableControl(0.0);
 	}
 
+  /**
+   * Return whether the controller is enabled.
+   *
+   * @returns true if enabled.
+   */
+  public boolean isEnabled() {
+    return m_controlEnabled;
+  }
+
 	/**
 	* Disable the closed loop controller.
 	*

wpilibj/wpilibJavaDevices/src/main/java/edu/wpi/first/wpilibj/CANTalon.java

@@ -1,11 +1,3 @@
-/* ----------------------------------------------------------------------------
- * This file was automatically generated by SWIG (http://www.swig.org).
- * Version 2.0.11
- *
- * Do not make changes to this file unless you know what you are doing--modify
- * the SWIG interface file instead.
- * ----------------------------------------------------------------------------- */
-
 package edu.wpi.first.wpilibj;
 
 import edu.wpi.first.wpilibj.hal.CanTalonSRX;
@@ -20,7 +12,7 @@ import edu.wpi.first.wpilibj.livewindow.LiveWindowSendable;
 import edu.wpi.first.wpilibj.tables.ITable;
 import edu.wpi.first.wpilibj.tables.ITableListener;
 
-public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedController, LiveWindowSendable {
+public class CANTalon implements MotorSafety, PIDOutput, PIDSource, PIDInterface, CANSpeedController, LiveWindowSendable {
 	private MotorSafetyHelper m_safetyHelper;
 	public enum TalonControlMode {
 		PercentVbus(0), Follower(5), Voltage(4), Position(1), Speed(2), Current(3), Disabled(15);
@@ -79,8 +71,10 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
 
 
   private CanTalonSRX m_impl;
-  TalonControlMode m_controlMode;
+  private TalonControlMode m_controlMode;
   private static double kDelayForSolicitedSignals = 0.004;
+  private double m_minimumInput;
+  private double m_maximumInput;
 
   int m_deviceNumber;
   boolean m_controlEnabled;
@@ -98,6 +92,7 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
     setProfile(m_profile);
     applyControlMode(TalonControlMode.PercentVbus);
   }
+
   public CANTalon(int deviceNumber,int controlPeriodMs) {
     m_deviceNumber = deviceNumber;
     m_impl = new CanTalonSRX(deviceNumber,controlPeriodMs); /* bound period to be within [1 ms,95 ms] */
@@ -183,6 +178,40 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
     set(outputValue);
   }
 
+  /**
+   * Resets the accumulated integral error and disables the controller.
+   *
+   * The only difference between this and {@link PIDController#reset} is that
+   * the PIDController also resets the previous error for the D term, but the
+   * difference should have minimal effect as it will only last one cycle.
+   */
+  public void reset() {
+    disable();
+    clearIAccum();
+  }
+
+  /**
+   * Return true if Talon is enabled.
+   *
+   * @return true if the Talon is enabled and may be applying power to the motor
+   */
+  public boolean isEnabled() {
+    return isControlEnabled();
+  }
+
+  /**
+   * Returns the difference between the setpoint and the current position.
+   *
+   * @return The error in units corresponding to whichever mode we are in.
+   * @see #set(double) set() for a detailed description of the various units.
+   */
+  public double getError() {return getClosedLoopError();}
+
+  /**
+   * Calls {@link #set(double)}.
+   */
+  public void setSetpoint(double setpoint) { set(setpoint); }
+
   /**
    * Flips the sign (multiplies by negative one) the sensor values going into
    *the talon.
@@ -487,6 +516,9 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
     changeControlMode(m_controlMode);
 		m_controlEnabled = true;
   }
+  public void enable() {
+    enableControl();
+  }
 
   public void disableControl() {
     m_impl.SetModeSelect(TalonControlMode.Disabled.value);
@@ -652,13 +684,6 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
     return CanTalonJNI.intp_value(fp);
   }
 
-	/**
-	 * Clear the accumulator for I gain.
-	 */
-	public void ClearIaccum()
-	{
-		SWIGTYPE_p_CTR_Code status = m_impl.SetParam(CanTalonSRX.param_t.ePidIaccum, 0);
-	}
   /**
    * Set the proportional value of the currently selected profile.
    *
@@ -743,6 +768,14 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
     m_impl.SetRampThrottle(rate);
   }
 
+	/**
+	 * Clear the accumulator for I gain.
+	 */
+	public void ClearIaccum()
+	{
+		SWIGTYPE_p_CTR_Code status = m_impl.SetParam(CanTalonSRX.param_t.ePidIaccum, 0);
+	}
+
   /**
    * Sets control values for closed loop control.
    *
@@ -816,6 +849,9 @@ public class CANTalon implements MotorSafety, PIDOutput, PIDSource, CANSpeedCont
 	}
 
   // TODO: Documentation for all these accessors/setters for misc. stuff.
+  public void clearIAccum() {
+ 		SWIGTYPE_p_CTR_Code status = m_impl.SetParam(CanTalonSRX.param_t.ePidIaccum, 0);
+  }
   public void setForwardSoftLimit(int forwardLimit) {
     m_impl.SetForwardSoftLimit(forwardLimit);
   }