#define pingPin 7
#define echoPin 8
long duration, cm,inches,m;

void setup() {
 Serial.begin(9600);
 pinMode(pingPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
    
  
   digitalWrite(pingPin, LOW);
   delayMicroseconds(2);
   
   digitalWrite(pingPin, HIGH);
   delayMicroseconds(10);
   
   digitalWrite(pingPin, LOW);
  
   duration = pulseIn(echoPin, HIGH);
   
   inches = microsecondsToInches(duration);
   cm = microsecondsToCentimeters(duration);

   m = inchesToMeter(inches);

   Serial.print(inches);
   Serial.print("in, ");
   
   Serial.print(cm);
   Serial.print("cm");

   Serial.print("Meter: ");
   Serial.print(m);
   
   
   Serial.println();
   delay(100);

}
long microsecondsToInches(long microseconds) {
   return microseconds / 74 / 2;
}

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

long inchesToMeter(long m) {
   return (m/39.37007874);
}