#define ECHO_PIN 2
#define TRIG_PIN 15
#define LED_RED 5
#define LED_ORANGE 21
#define LED_GREEN 25
#define BUZZER_PIN_1 19
#define BUZZER_PIN_2 12

const long interval = 1000; // Interval for distance measurements

void setup() {
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_ORANGE, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(BUZZER_PIN_1, OUTPUT);
  pinMode(BUZZER_PIN_2, OUTPUT);
}

void loop() {
  static unsigned long previousMillis = 0;
  unsigned long currentMillis = millis();

  // Check if it's time to take a distance reading
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Trigger the ultrasonic sensor
    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);
  
    // Read the echo time
    int duration = pulseIn(ECHO_PIN, HIGH);
    float distance = duration * 0.034 / 2;  // Calculate distance in cm

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

    // Check distance and activate corresponding outputs
    if (distance > 200) {
      Serial.println("Safe Zone...");
      digitalWrite(LED_GREEN, HIGH);
      digitalWrite(LED_ORANGE, LOW);
      digitalWrite(LED_RED, LOW);
      noTone(BUZZER_PIN_1);
      noTone(BUZZER_PIN_2);
    } 
    else if (distance <= 200 && distance > 100) {
      Serial.println("Warning Zone!");
      digitalWrite(LED_GREEN, LOW);
      digitalWrite(LED_ORANGE, HIGH);
      digitalWrite(LED_RED, LOW);
      tone(BUZZER_PIN_1, 1000);  // Activate yellow buzzer
    } 
    else if (distance <= 100) {
      Serial.println("Danger Zone! Alarm Activated!!!");
      digitalWrite(LED_GREEN, LOW);
      digitalWrite(LED_ORANGE, LOW);
      digitalWrite(LED_RED, HIGH);
      tone(BUZZER_PIN_2, 1000); // Activate red buzzer
    }
  }
}