const int TRIG_PIN=2;
const int ECHO_PIN=4;
long duration,distance;
void setup() {

  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN,INPUT);
}

void loop() {
   distance=getDistanceInCentimeters();
   Serial.println("Distance=" + String(distance));
   delay(1000);
}
long getDistanceInCentimeters(){
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration=pulseIn(ECHO_PIN,HIGH);
  return (duration*0.034/2)+1;
}