const int triggerPin = 8;
const int echoPin = 9;
long duration;
int distanceCm;

void setup()
{
  pinMode(triggerPin , OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
  
}
void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(triggerPin,0);
  delayMicroseconds(2);
  digitalWrite(triggerPin,1);
   delayMicroseconds(10);
    digitalWrite(triggerPin,0);
  duration = pulseIn(echoPin,1);
  distanceCm = duration*0.0343/2;
  Serial.print("Distance = ");
  Serial.print(distanceCm);
  Serial.println("cm");
  delay(1000);
}