#define MQ2_ANA A1
#define MQ2_DIG 2
#define redLed 12
#define buzzer 8
#define dht22 1

void setup() 
{
  Serial.begin(9600);
  pinMode(MQ2_ANA, INPUT);
  pinMode(MQ2_DIG, INPUT);
  pinMode(redLed, OUTPUT);
  pinMode(buzzer, OUTPUT);
}

void loop() 
{
  Serial.print("smoke/gas: ");
  int smokVal = analogRead(MQ2_ANA);
  Serial.println(map(smokVal, 0, 1023, 0, 100));
  Serial.print("Digital: ");
  Serial.println(digitalRead(MQ2_DIG));
  delay(1000);

  if(smokVal > 450)
  {
   digitalWrite(redLed, HIGH); 
   delay(1000);
   digitalWrite(redLed, LOW);
   tone(buzzer, 80);
   delay(500);
   noTone(buzzer);
  }
  else
  {
   digitalWrite(redLed, LOW); 
   noTone(buzzer);
  }
}