#define TRIG_PIN 2
#define ECHO_PIN 4

void setup() {
  Serial.begin(9600);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  long duration, distance;

  // Clear the trigger pin
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  // Send a 10us pulse to trigger
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Read the pulse on the echo pin
  duration = pulseIn(ECHO_PIN, HIGH);

  // Calculate distance in cm
  distance = (duration * 0.0343) / 2;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(1000); // Delay between readings
}