Added Ultrasonic example program in Java and C++, updated examples XML.

Change-Id: I510bef33d8565d124894d926d6634b04b1b6ca28

eclipse-plugins/edu.wpi.first.wpilib.plugins.cpp/resources/templates/examples/Ultrasonic/src/Robot.cpp

@@ -0,0 +1,66 @@
+#include "WPILib.h"
+
+/**
+ * This is a sample program demonstrating how to use an ultrasonic sensor and proportional control to
+ * maintain a set distance from an object.
+ */
+class Robot: public SampleRobot {
+	AnalogInput *ultrasonic; //ultrasonic sensor
+	RobotDrive *myRobot;
+
+public:
+	const int ultrasonicChannel = 3; //analog input pin
+
+	//channels for motors
+	const int leftMotorChannel = 1;
+	const int rightMotorChannel = 0;
+	const int leftRearMotorChannel = 3;
+	const int rightRearMotorChannel = 2;
+
+	int holdDistance = 12; //distance in inches the robot wants to stay from an object
+	const double valueToInches = 0.125; //factor to convert sensor values to a distance in inches
+	const double pGain = 0.05; //proportional speed constant
+
+
+	Robot() :
+			SampleRobot() {
+		//make objects for the sensor and drive train
+		ultrasonic = new AnalogInput(ultrasonicChannel);
+		myRobot = new RobotDrive(new CANTalon(leftMotorChannel),
+				new CANTalon(leftRearMotorChannel),
+				new CANTalon(rightMotorChannel),
+				new CANTalon(rightRearMotorChannel));
+	}
+
+	/**
+	 * Runs during autonomous.
+	 */
+	void Autonomous() {
+
+	}
+
+	/**
+	 *  Tells the robot to drive to a set distance (in inches) from an object using
+	 *  proportional control.
+	 */
+	void OperatorControl() {
+
+		double currentDistance; //distance measured from the ultrasonic sensor values
+		double currentSpeed; //speed to set the motor
+
+		while (IsOperatorControl() && IsEnabled()) {
+			currentDistance = ultrasonic->GetValue() * valueToInches; //sensor returns a value from 0-4095 that is scaled to inches
+			currentSpeed = (holdDistance - currentDistance) * pGain; //convert distance error to a motor speed
+			myRobot->Drive(currentSpeed, 0); //drive robot
+		}
+	}
+
+	/**
+	 * Runs during test mode
+	 */
+	void Test() {
+
+	}
+};
+
+START_ROBOT_CLASS(Robot);

eclipse-plugins/edu.wpi.first.wpilib.plugins.cpp/resources/templates/examples/examples.xml

@@ -261,6 +261,26 @@
     <file source="examples/MecanumDrive/src/Robot.cpp" destination="src/Robot.cpp"></file>
   </files>
   </example>
+  
+  
+<example>
+  <name>Ultrasonic</name>
+  <description>Demonstrate maintaining a set distance using an ultrasonic sensor.</description>
+  <tags>
+    <tag>Getting Started with C++</tag>
+    <tag>Robot and Motor</tag>
+    <tag>CAN</tag>
+    <tag>Complete List</tag>
+	<tag>Sensors</tag>
+  </tags>
+  <packages>
+    <package>src</package>
+  </packages>
+  <files>
+    <file source="examples/Ultrasonic/src/Robot.cpp" destination="src/Robot.cpp"></file>
+  </files>
+  </example>
+
 
 
   <example>