Parallax Ping Fun


I am trying to insert some logic into the example Parallax Ping code. I just want it to turn on the onboard LED on an UNO but it is not working. Could someone please take a look at my if/then statement. What am I missing?



/* 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
   created 3 Nov 2008
   by David A. Mellis
   modified 30 Aug 2011
   by Tom Igoe
   This example code is in the public domain.


// this constant won't change.  It's the pin number
// of the sensor's output:
const int pingPin = 7;

void setup() {
  // initialize serial communication:

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.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  pinMode(pingPin, OUTPUT);
  digitalWrite(pingPin, LOW);
  digitalWrite(pingPin, HIGH);
  digitalWrite(pingPin, LOW);

  // The same pin is used to read the signal from the PING))): a HIGH
  // pulse whose duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  pinMode(pingPin, INPUT);
  duration = pulseIn(pingPin, HIGH);

  // convert the time into a distance
  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);

    if (inches < 6)
    digitalWrite(13, HIGH);
    digitalWrite(13, LOW);
  Serial.print("in, ");

long microsecondsToInches(long microseconds)
  // According to Parallax's datasheet for the PING))), there are
  // 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
  // second).  This gives the distance travelled by the ping, outbound
  // and return, so we divide by 2 to get the distance of the obstacle.
  // See:
  return microseconds / 74 / 2;

long microsecondsToCentimeters(long microseconds)
  // The speed of sound is 340 m/s or 29 microseconds per centimeter.
  // The ping travels out and back, so to find the distance of the
  // object we take half of the distance travelled.
  return microseconds / 29 / 2;

You don’t seem to have set up the pin for the LED. Where is the pinMode in your setup() function for the LED?

Thanks HazardsMind! I am just getting back into this and forgot the basics.