int trigPin = 5;
 int echoPin = 18;
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701
long duration;
float distanceCm;
float distanceInch;
void setup()  {
  Serial.begin(115200);
  pinMode(trigPin,  OUTPUT);
  pinMode(echoPin,  INPUT);
}
void loop()  {
  digitalWrite(trigPin,  LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin,  HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin,  LOW);
  duration = pulseIn(echoPin,  HIGH);
  distanceCm = duration * SOUND_SPEED/2;
  distanceInch = distanceCm* CM_TO_INCH;
  Serial.print("Distance (cm) : ");
  Serial.print(distanceCm);
  Serial.print("Distance (inch) : ");
  Serial.println(distanceInch);
  delay(1000);
}