// Define pins for the ultrasonic sensor
const int trigPin = 9;
const int echoPin = 8;

// Variables to store the duration of the echo and the calculated distance
long duration;
float distance;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Configure trigger and echo pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Print a start message to the Serial Monitor
  Serial.println("HC-SR04 Ultrasonic Sensor Test");
}

void loop() {
  // Clear the trigger pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Send a 10-microsecond pulse to the trigger pin
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the duration of the echo pulse
  duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in centimeters
  distance = (duration * 0.034) / 2;

  // Print the distance to the Serial Monitor
//  Serial.print("Distance: ");
  Serial.println(distance);
 // Serial.println(" cm");

  // Wait 500 milliseconds before the next measurement
  delay(500);
}