void setup() {
	// init the display
  pinMode(2, INPUT_PULLUP);
  pinMode(3, OUTPUT);


  pinMode(7, OUTPUT);
  pinMode(13, OUTPUT);
  Serial.begin(9600);

}

void loop() {
    digitalWrite(3, HIGH);
    delay(10);
    digitalWrite(3, LOW);

    int duration = pulseIn(2, HIGH);
    int distance = duration/29/2;

    Serial.println("Distance in cm: ");
    Serial.println(distance);

  delay(1000);
}