#define TRIG_PIN 9
#define ECHO_PIN 10

unsigned long duration;
unsigned int distance;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(TRIG_PIN, LOW);
  delay (10);

  digitalWrite(TRIG_PIN, HIGH);
  delay (10);
  digitalWrite(TRIG_PIN, LOW);

  duration = pulseIn(ECHO_PIN, HIGH);

  distance = duration * 0.034 /2;

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

  delay (500);



}