Gerbang Logika Pemrograman

const int PIR_PIN    = 2;   // Sensor gerak
const int LDR_PIN    = A0;  // Sensor cahaya
const int TOMBOL_PIN = 7;   // Tombol arm/disarm
const int LED_ALARM  = 13;
const int LED_STATUS = 12;
const int BUZZER_PIN = 8;

bool sistemArmed = false;
const int AMBANG_GELAP = 400; // LDR threshold

void setup() {
  pinMode(PIR_PIN, INPUT);
  pinMode(TOMBOL_PIN, INPUT_PULLUP);
  pinMode(LED_ALARM, OUTPUT);
  pinMode(LED_STATUS, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  bool adaGerakan = digitalRead(PIR_PIN) == HIGH;
  bool gelap = analogRead(LDR_PIN) < AMBANG_GELAP;
  bool tombolDitekan = digitalRead(TOMBOL_PIN) == LOW;
  
  // Toggle arm dengan tombol
  if (tombolDitekan) {
    sistemArmed = !sistemArmed;
    Serial.println(sistemArmed ? "Sistem: ARMED" : "Sistem: DISARMED");
    delay(500); // Debounce sederhana
  }
  
  // Alarm berbunyi HANYA jika:
  // Sistem aktif (armed) AND ada gerakan AND kondisi gelap
  bool alarming = sistemArmed && adaGerakan && gelap;
  
  // Juga alarm jika sistem aktif AND ada gerakan (siang atau malam)
  // bool alarming = sistemArmed && adaGerakan; // Versi alternatif
  
  digitalWrite(LED_ALARM, alarming);
  digitalWrite(LED_STATUS, sistemArmed);
  
  if (alarming) {
    tone(BUZZER_PIN, 1200, 500);
    Serial.println("⚠ INTRUSI TERDETEKSI! (Gelap + Ada Gerakan)");
  } else {
    noTone(BUZZER_PIN);
  }
  
  delay(200);
}