#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

#define SENSOR_GAS_PIN 34
#define DHT_PIN 15
#define DHT_TYPE DHT22
#define LED_HIJAU 18
#define LED_MERAH 19
#define BUZZER 23

LiquidCrystal_I2C lcd(0x27, 16, 2);
DHT dht(DHT_PIN, DHT_TYPE);

int ambangGas = 30; // Threshold gas 30%
float ambangSuhu = 50.0; // indikator kebakaran

void setup() {
  Serial.begin(115200);
  dht.begin();
  
  pinMode(LED_HIJAU, OUTPUT);
  pinMode(LED_MERAH, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Sistem Keamanan");
  lcd.setCursor(0, 1);
  lcd.print("Gas & Kebakaran");
  delay(2000);
  lcd.clear();
}

void loop() {
  // Potensiometer
  int nilaiAnalog = analogRead(SENSOR_GAS_PIN);
  int persentaseGas = map(nilaiAnalog, 0, 4095, 0, 100);
  
  // DHT22
  float suhu = dht.readTemperature();
  lcd.setCursor(0, 0);
  lcd.print("Gas:");
  lcd.print(persentaseGas);
  lcd.print("% T:");
  lcd.print(suhu, 1);
  lcd.print("C  "); 
  
  lcd.setCursor(0, 1);
  if (suhu >= ambangSuhu) {
    lcd.print("AWAS KEBAKARAN! ");
    digitalWrite(LED_HIJAU, LOW);
    digitalWrite(LED_MERAH, HIGH);
    tone(BUZZER, 1000);
  } 
  else if (persentaseGas >= ambangGas) {
    lcd.print("AWAS GAS BOCOR! ");
    digitalWrite(LED_HIJAU, LOW);
    digitalWrite(LED_MERAH, HIGH);
    tone(BUZZER, 1000);
  } 
  else {
    lcd.print("Kondisi Aman    ");
    digitalWrite(LED_HIJAU, HIGH);
    digitalWrite(LED_MERAH, LOW);
    noTone(BUZZER);
  }
  
  delay(1000); 
}