#include <DHT.h>

#define gasPin   A0       // MQ-2 analog output
#define led1     8        // LED indikator suhu/gas
#define relay    11        // relay indikator kipas
#define buzzPin  9        // Buzzer pin
#define DHTPIN   A1       // DHT22 data pin
#define DHTTYPE  DHT22    // Tipe sensor DHT

DHT dht(DHTPIN, DHTTYPE);

// Threshold MQ-2 (kalibrasi disesuaikan)
const int gasThreshold = 500;

// Batas suhu untuk menyalakan LED (°C)
const float tempThreshold = 33.0;

void setup() {
  Serial.begin(9600);
  dht.begin();
  pinMode(led1, OUTPUT);
  pinMode(relay, OUTPUT);
  pinMode(buzzPin, OUTPUT);
  Serial.println("=== Gas + Suhu + Cahaya Monitoring ===");
}

// Fungsi pembacaan gas
void gasSensor() {
  int gasValue = analogRead(gasPin);
  float gasVoltage = gasValue * (5.0 / 1023.0);

  Serial.print("Gas ADC = ");
  Serial.print(gasValue);
  Serial.print(" (");
  Serial.print(gasVoltage, 2);
  Serial.println(" V)");

  if (gasValue > gasThreshold) {
    digitalWrite(led1, HIGH);
    tone(buzzPin, 1000);
    Serial.println("** GAS TERDETEKSI! **");
  } else {
    digitalWrite(led1, LOW);
    noTone(buzzPin);
  }
}

// Fungsi pembacaan DHT22
void dht22() {
  float suhu = dht.readTemperature();
  float kelembapan = dht.readHumidity();

  if (isnan(suhu) || isnan(kelembapan)) {
    Serial.println("Gagal membaca DHT!");
    return;
  }

  Serial.println("-- Monitoring Suhu Ruang --");
  Serial.print("Suhu = ");
  Serial.print(suhu);
  Serial.print(" °C, Kelembapan = ");
  Serial.print(kelembapan);
  Serial.println(" %");

  if (suhu > tempThreshold) {
    digitalWrite(relay, HIGH);
    Serial.println("-- Suhu tinggi, RELAY ON --");
  } else {
    digitalWrite(relay, LOW);
  }
}

// Loop utama
void loop() {
  dht22();
  gasSensor();

  Serial.println("----------------------------\n");
  delay(2000);
}