#define MQ2_ANA A1
#define MQ2_DIG 2
#define Threshold 400
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
int buzzerPin = 13;
int ledPin = 5;

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(2,0);
  lcd.print("RAFFY DAFA");
  lcd.setCursor(4,1);
  lcd.print("INF 5");
  delay(4000);
  lcd.clear();
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(MQ2_ANA, INPUT);
  pinMode(MQ2_DIG, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.print("Analog: ");
  Serial.println(analogRead(MQ2_ANA));
  Serial.print("Digital: ");
  Serial.println(digitalRead(MQ2_DIG));
  delay(300);
  lcd.setCursor(2,0);
  lcd.print("UAP GAS = ");
  lcd.setCursor(10,0);
  lcd.print(analogRead(MQ2_ANA));
  if (analogRead(MQ2_ANA) > Threshold) {
    tone(buzzerPin, 200);
    digitalWrite(ledPin, HIGH); 
  }
  else
  {
    noTone(buzzerPin);
    digitalWrite(ledPin, LOW); 
  }
  delay(300);
  
}