// www.robotronix.co.il // Distance sensor
// learn arduino לימוד ארדואינו קורס C506

const int pingPin = 4; // Trigger Pin of Ultrasonic Sensor
const int echoPin = 2; // Echo Pin of Ultrasonic Sensor

void setup() {
   Serial.begin(9600); // Starting Serial Terminal
}

void loop() {
   long duration, inches, cm;
   pinMode(pingPin, OUTPUT);
   digitalWrite(pingPin, LOW);
   delayMicroseconds(2);
   digitalWrite(pingPin, HIGH);
   delayMicroseconds(10);
   digitalWrite(pingPin, LOW);
   pinMode(echoPin, INPUT);
   duration = pulseIn(echoPin, HIGH);
   inches =      microsecondsToInches(duration);
   cm =     microsecondsToCentimeters(duration);
  // Serial.print(inches);
  // Serial.print("in, ");
   Serial.print(cm);
   Serial.print("cm");
   Serial.println();
   delay(250);
}

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

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