Support for the CAN power distribution panel

Change-Id: If4f8f7f050bf1095221cf16f030a6a8a67532656

wpilibj/wpilibJava/src/main/java/edu/wpi/first/wpilibj/PowerDistributionPanel.java

@@ -0,0 +1,75 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.first.wpilibj;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+import edu.wpi.first.wpilibj.hal.PDPJNI;
+import edu.wpi.first.wpilibj.hal.HALUtil;
+import edu.wpi.first.wpilibj.livewindow.LiveWindowSendable;
+import edu.wpi.first.wpilibj.can.CANTimeoutException;
+
+/**
+ * Class for getting voltage, current, and temperature from the CAN PDP
+ * @author Thomas Clark
+ */
+public class PowerDistributionPanel extends SensorBase {
+	public PowerDistributionPanel() {
+	}
+	
+	/**
+	 * @return The voltage of the PDP
+	 */
+	public double getVoltage() throws CANTimeoutException {
+		ByteBuffer status = ByteBuffer.allocateDirect(4);
+		status.order(ByteOrder.LITTLE_ENDIAN);
+		
+		double voltage = PDPJNI.getPDPVoltage(status.asIntBuffer());
+		
+		if(status.asIntBuffer().get(0) != 0) {
+			throw new CANTimeoutException();
+		}
+		
+		return voltage;
+	}
+
+	/**
+	 * @return The temperature of the PDP in degrees Celsius
+	 */
+	public double getTemperature() throws CANTimeoutException {
+		ByteBuffer status = ByteBuffer.allocateDirect(4);
+		status.order(ByteOrder.LITTLE_ENDIAN);
+		
+		double temperature = PDPJNI.getPDPTemperature(status.asIntBuffer());
+		
+		if(status.asIntBuffer().get(0) != 0) {
+			throw new CANTimeoutException();
+		}
+		
+		return temperature;
+	}
+	
+	/**
+	 * @return The current of one of the PDP channels (channels 1-16) in Amperes
+	 */
+	public double getCurrent(int channel) throws CANTimeoutException {
+		ByteBuffer status = ByteBuffer.allocateDirect(4);
+		status.order(ByteOrder.LITTLE_ENDIAN);
+		
+		double current = PDPJNI.getPDPChannelCurrent((byte)channel, status.asIntBuffer());
+		
+		checkPDPChannel(channel);
+		
+		if(status.asIntBuffer().get(0) != 0) {
+			throw new CANTimeoutException();
+		}
+		
+		return current;
+	}
+}

wpilibj/wpilibJava/src/main/java/edu/wpi/first/wpilibj/SensorBase.java

@@ -58,6 +58,10 @@ public abstract class SensorBase { // TODO: Refactor
      * Number of relay channels per sidecar
      */
     public static final int kRelayChannels = 4;
+    /**
+     * Number of power distribution channels
+     */
+    public static final int kPDPChannels = 16;
 
     private static int m_defaultAnalogModule = 1;
     private static int m_defaultDigitalModule = 1;
@@ -226,6 +230,18 @@ public abstract class SensorBase { // TODO: Refactor
         }
     }
 
+    /**
+     * Verify that the power distribution channel number is within limits. 
+     * Channel numbers are 1-based.
+     *
+     * @param channel The channel number to check.
+     */
+    protected static void checkPDPChannel(final int channel) {
+        if (channel <= 0 || channel > kPDPChannels) {
+            System.err.println("Requested solenoid channel number is out of range.");
+        }
+    }
+
     /**
      * Get the number of the default analog module.
      *

wpilibj/wpilibJava/src/main/java/edu/wpi/first/wpilibj/hal/PDPJNI.java

@@ -0,0 +1,10 @@
+package edu.wpi.first.wpilibj.hal;
+
+import java.nio.ByteBuffer;
+import java.nio.IntBuffer;
+
+public class PDPJNI extends JNIWrapper {
+	public static native double getPDPTemperature(IntBuffer status);
+	public static native double getPDPVoltage(IntBuffer status);
+	public static native double getPDPChannelCurrent(byte channel, IntBuffer status);
+}