int trigpin = 5;
constconst 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;
  distanceInch = distanceCm * CM_TO_INCH;
  Serial.print("Distance (inch): ");
  Serial.println(distanceCm);
  Serial.print("Distance (inch): ");
  Serial.println(distanceInch);
  delay(1000);

}