#define PIR_SENSOR 2      
#define LDR_SENSOR A0      
#define LED_PIR 3          
#define LED_LDR 4         
#define LED_READY 5        
#define BUZZER 6          

void setup() {
  pinMode(PIR_SENSOR, INPUT);
  pinMode(LED_PIR, OUTPUT);
  pinMode(LED_LDR, OUTPUT);
  pinMode(LED_READY, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  // System Ready Signal
  digitalWrite(LED_READY, HIGH);
  tone(BUZZER, 1000);         
  delay(2000);                   
  noTone(BUZZER);
  digitalWrite(LED_READY, LOW);
}

void loop() {
  // Read sensors
  int pirStatus = digitalRead(PIR_SENSOR); 
  int ldrValue = analogRead(LDR_SENSOR);  
  int ldrThreshold = 500;                 
  
  if (pirStatus == HIGH) {
    digitalWrite(LED_PIR, HIGH);  
    tone(BUZZER, 2000, 500);      
  } else {
    digitalWrite(LED_PIR, LOW);
  }

  if (ldrValue < ldrThreshold) {
    digitalWrite(LED_LDR, HIGH); 
    tone(BUZZER, 500, 1000);   
  } else {
    digitalWrite(LED_LDR, LOW);
  }

  delay(100);
}