#define MQ2pin 8          // Digital output MQ2
#define MQ2_ANALOG A0     // Analog output MQ2
#define LED_PIN 3         // LED indikator

int digitalValue;         // nilai digital MQ2
int gasValue;             // nilai analog MQ2 (simulasi ppm)

void setup() {
  Serial.begin(9600);
  Serial.println("MQ2 warming up...");
  delay(200); // warm up sensor

  pinMode(MQ2pin, INPUT);    // Digital pin MQ2
  pinMode(MQ2_ANALOG, INPUT);// Analog pin MQ2
  pinMode(LED_PIN, OUTPUT);  // LED sebagai output
}

void loop() {

  // --- Membaca nilai digital MQ2 ---
  digitalValue = digitalRead(MQ2pin);

  // --- Membaca nilai analog MQ2 ---
  gasValue = analogRead(MQ2_ANALOG);

  // --- Tampilkan ke serial monitor ---
  Serial.print("Digital Output: ");
  Serial.print(digitalValue);

  if (digitalValue) {
    Serial.print("  |  Smoke: -");
  } else {
    Serial.print("  |  Smoke: Detected!");
  }

  Serial.print("  |  Gas Value: ");
  Serial.println(gasValue);

  // --- Logika LED indikator gas ---
  if (gasValue > 400) {
    digitalWrite(LED_PIN, HIGH);  // LED menyala
  } else {
    digitalWrite(LED_PIN, LOW);   // LED mati
  }

  delay(2000); // jeda 2 detik
}