const int trigPin = 9;    // Trig pin
const int echoPin = 10;   // Echo pin
long duration;            // Variable to store the time of flight
int distance;             // Variable to store the calculated distance

void setup() {
  pinMode(trigPin, OUTPUT);  // Set the trig pin as output
  pinMode(echoPin, INPUT);   // Set the echo pin as input
  Serial.begin(9600);        // Initialize serial communication
}

void loop() {
  // Send the ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);          // Wait for 2 microseconds
  digitalWrite(trigPin, HIGH);   // Trigger the pulse
  delayMicroseconds(10);         // Wait for 10 microseconds
  digitalWrite(trigPin, LOW);    // Stop the pulse

  // Measure the time taken for the echo to return
  duration = pulseIn(echoPin, HIGH);  // Get the duration in microseconds

  // Calculate the distance based on the speed of sound (0.034 cm per microsecond)
  distance = duration * 0.034 / 2;

  // Display the distance in the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(1000);  // Wait 1 second before repeating the measurement
}