updated example to match tutorial style guide

build/shared/dist/examples/Sensors/Ping/Ping.pde

@@ -1,16 +1,42 @@
-int pingPin = 7;
+/* Ping))) Sensor
+  
+   This sketch reads a PING))) ultrasonic rangefinder and returns the
+   distance to the closest object in range. To do this, it sends a pulse
+   to the sensor to initiate a reading, then listens for a pulse 
+   to return.  The length of the returning pulse is proportional to 
+   the distance of the object from the sensor.
+     
+   The circuit:
+	* +V connection of the PING))) attached to +5V
+	* GND connection of the PING))) attached to ground
+	* SIG connection of the PING))) attached to digital pin 7
 
-void setup()
+   http://www.arduino.cc/en/Tutorial/Ping
-{
+   
+   created 3 Nov 2008
+   by David A. Mellis
+   modified 30 Jun 2009
+   by Tom Igoe
+
+ */
+
+// this constant won't change.  It's the pin number
+// of the sensor's output:
+const int pingPin = 7;
+
+void setup() {
+  // initialize serial communication:
   Serial.begin(9600);
 }
 
 void loop()
 {
+  // establish variables for duration of the ping, 
+  // and the distance result in inches and centimeters:
   long duration, inches, cm;
 
   // The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
-  // We give a short LOW pulse beforehand to ensure a clean HIGH pulse.
+  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
   pinMode(pingPin, OUTPUT);
   digitalWrite(pingPin, LOW);
   delayMicroseconds(2);