int trigPin = 6;
int echoPin = 5;

void setup() {
  pinMode(8, OUTPUT);  // Pin for buzzer
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
  delay(1000);
}

void loop() {
  // Send a pulse to the trigger pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);  // Send a 10-microsecond pulse
  digitalWrite(trigPin, LOW);

  // Measure the pulse duration on the echo pin
  int duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in centimeters
  long distance = duration * 0.0344 / 2;

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

  // Map the distance (20cm to 200cm) to a frequency (2000Hz to 4000Hz)
  long frequency = map(distance, 20, 200, 2000, 4000);

  // Make sure the frequency is within the audible range (2000Hz - 4000Hz)
  frequency = constrain(frequency, 2000, 4000);

  // Play tone based on mapped frequency
  tone(8, frequency, 2000);  // Play the tone for 2 seconds
  delay(2500);  // Wait for the tone to finish before the next reading

  // Stop the tone after it finishes
  noTone(8);
}