#define TRIG_PIN 27    // Changed to GPIO 27
#define ECHO_PIN 13    // Changed to GPIO 13
#define BUZZER_PIN 33  // Changed to GPIO 33

long duration;
float distance;

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  
  Serial.begin(115200);
}

void loop() {
  // Send trigger signal
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  // Read the echo time
  duration = pulseIn(ECHO_PIN, HIGH);
  
  // Calculate the distance (in meters)
  distance = (duration * 0.034 / 2) / 100;
  
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" m");
  
  if (distance < 5.0) { // If vehicle is within 5 meters
    tone(BUZZER_PIN, 1000);  // Generate a 1kHz tone on buzzer
  } else {
    noTone(BUZZER_PIN);      // Stop the tone on buzzer
  }
  
  delay(100);
}