#define trigPin A0  // Trigger pin connected to D9
#define echoPin A2  // Echo pin connected to D10

long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT); // Trigger pin as output
  pinMode(echoPin, INPUT);  // Echo pin as input
  Serial.begin(9600);       // Start serial communication
}

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

  // Send a 10µs HIGH pulse to trigger the sensor
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read the echoPin and measure the duration of the pulse
  duration = pulseIn(echoPin, HIGH);

  // Calculate distance (speed of sound is 34300 cm/s)
  distance = duration * 0.034 / 2;

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

  delay(500); // Wait a bit before next measurement
}