int Trig_pin=5;
int Echo_pin=18;
long duration;
float Speed_of_sound=0.034;
float dist_in_cm;

void setup(){
  Serial.begin(115200);
    pinMode(Trig_pin, OUTPUT);
      pinMode(Echo_pin, INPUT);
      } 
      void loop(){
       digitalWrite(Trig_pin, LOW);
       delayMicroseconds(2);
       digitalWrite(Trig_pin, HIGH);
       delayMicroseconds(10);
       digitalWrite(Trig_pin, LOW);

       duration=pulseIn(Echo_pin,HIGH);
       dist_in_cm=duration*Speed_of_sound/2;
       Serial.print("The distance is ::");
       Serial.println(dist_in_cm);
       delay(10);
}