#define echoPin 8
#define trigPin 9
long duration;
float distanceCm;
float distanceInch;

void setup() {
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
Serial.begin(9600);
}

void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distanceCm = duration * 0.0344 / 2;
distanceInch = distanceCm / 2.54;
Serial.print("distance (cm) ");
Serial.print(distanceCm);
Serial.println(" cm");
Serial.print("distance (inch) ");
Serial.print(distanceInch);
Serial.println(" inch");
delay(100);
}