const int trigPin = 11;
const int echoPin = 12;
long duration;
int distance;
void setup()
 
{
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
}
  void loop()
{
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
duration = pulseIn(echoPin, HIGH);
distance = duration*0.034/2;
delay(500);
Serial.println(distance);
}