// Define pin numbers
const int trigPin = 12;  // Pin connected to Trig of HC-SR04
const int echoPin = 11; // Pin connected to Echo of HC-SR04

// Variables to store time and distance
long duration;
float distance;

void setup() {
  // Start the serial communication
  Serial.begin(9600);
  
  // Define the pin modes
  pinMode(trigPin, OUTPUT); // Trig pin as output
  pinMode(echoPin, INPUT);  // Echo pin as input
  
  Serial.println("Ultrasonic Sensor HC-SR04 Initialized");
}

void loop() {
  // Clear the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Trigger the sensor by setting the trigPin HIGH for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read the echoPin, and calculate the duration it took for the pulse to return
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate the distance in cm (duration * 0.034 / 2)
  distance = (duration * 0.034) / 2;
  
  // Print the distance to the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  // Wait before the next measurement
  delay(500);
}