#include <LiquidCrystal_I2C.h>
#include <Servo.h>

#define MQ5_AO A0  // Analog pin for MQ-5
#define MQ5_DO 7   // Digital pin for MQ-5
Servo myServo;  // Create servo object
int redled=3;
int greenled=2;
int buzzer=4;
LiquidCrystal_I2C lcd(0x27,18,19);  // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup() 
{
  pinMode(redled, OUTPUT);
  pinMode(greenled, OUTPUT);
  pinMode(buzzer, OUTPUT);

  digitalWrite(redled, LOW);
  delay(500);
  digitalWrite(redled, HIGH);
  digitalWrite(greenled, LOW);
  delay(500);
  digitalWrite(greenled, HIGH);

  digitalWrite(buzzer, LOW);
  delay(500);
  digitalWrite(buzzer, HIGH);

  myServo.attach(9);  // Attach servo to pin 9
  myServo.write(0);  // Start at 0 degrees  

    pinMode(MQ5_DO, INPUT);

    lcd.init();      // Initialize the LCD
    lcd.backlight(); // Turn on the backlight
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Welcome to all");
    lcd.setCursor(0,1);
    lcd.print("Gas Sensor Ready");
    delay(2000);
    lcd.clear();
}

void loop() 
{
    int gasValue = analogRead(MQ5_AO);  // Read analog value
    int gasDetected = digitalRead(MQ5_DO); // Read digital signal

    if (gasValue<=170) 
    {
      lcd.setCursor(0,0);
      lcd.print("Status: Safe    ");
      lcd.setCursor(0, 1);
      lcd.print("No Gas Leakage");
      digitalWrite(greenled, LOW);
      digitalWrite(buzzer, HIGH);
      myServo.write(0);
      delay(500);
      digitalWrite(greenled, HIGH);
    } 
    if (gasValue>170) 
    {
      lcd.setCursor(0,0);
      lcd.print("Status: Not Safe   ");
      lcd.setCursor(0, 1);
      lcd.print("Gas Detected!...");
      digitalWrite(redled, LOW);
      digitalWrite(buzzer, LOW);   
      myServo.write(100);  
      delay(500);
      digitalWrite(redled, HIGH);
       
    }
}