#define SPEAKER_PIN 8
#define DISTANCE_THRESHOLD 20
#define TRIG_PIN 9
#define ECHO_PIN 10

void setup() {
  pinMode(SPEAKER_PIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.begin(9600);
}

void loop() {
  int distance = 20;  // Set the distance to 20 directly

  Serial.print("Distance: ");
  Serial.println(distance);

  if (distance == DISTANCE_THRESHOLD) {
    // Simple beep
    tone(SPEAKER_PIN, 1000);  // Adjust the frequency (Hz) as needed
    delay(100);               // Adjust the duration of the beep
    noTone(SPEAKER_PIN);
  }
  delay(500);  // Adjust the delay between distance measurements
}