this reads out the distance from an ultrasonic sensor

Ultrasonic Sensor HC-SR04.ino

int trigPin = 3;
int echoPin = 5; 
long duration;
long distance;
long cm;

void setup()
{
  Serial.begin(9600);  //this starts the talking
  pinMode(trigPin, OUTPUT); //we will tell the 
  //ultrasonic to take a measurement by triggering
  //this pin
  pinMode(echoPin, INPUT); //get a message via
  //this pin
}

void loop()
{
delay(50); 
distance = getDistance();
Serial.println(distance);
}


long getDistance() 
{  
//give the module nudge
//a pulse.  __--__ 
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10); 
digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);
cm = microsecondsToCentimeters(duration);

return cm;
}  


long microsecondsToCentimeters(long microseconds) {
  return microseconds / 29 / 2;
}