#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // Address 0x27, 16 columns and 2 rows

const int gasSensorPin = A0; // Analog pin connected to the sensor output
const int greenLedPin = 8;   // Digital pin for Green LED
const int redLedPin = 12;     // Digital pin for Red LED
const int thresholdValue = 500; // Adjust this threshold according to your sensor and calibration

void setup() {
  lcd.init(); // Initialize the LCD
  lcd.backlight(); // Turn on the backlight
  
  Serial.begin(9600); // Initialize serial communication
  
  lcd.setCursor(0, 0);
  lcd.print("Gas Sensor:");
  
  pinMode(greenLedPin, OUTPUT);
  pinMode(redLedPin, OUTPUT);
}

void loop() {
  int sensorValue = analogRead(gasSensorPin); // Read the analog sensor value
  
  Serial.print("Gas Sensor Value: ");
  Serial.println(sensorValue); // Print the sensor value to serial monitor
  
  lcd.setCursor(0, 1);
  lcd.print("Value: ");
  lcd.print(sensorValue); // Display sensor value on LCD
  
  // Control LEDs based on sensor value
  if (sensorValue < thresholdValue) {
    digitalWrite(greenLedPin, HIGH); // Turn on Green LED
    digitalWrite(redLedPin, LOW);    // Turn off Red LED
  } else {
    digitalWrite(greenLedPin, LOW);  // Turn off Green LED
    digitalWrite(redLedPin, HIGH);   // Turn on Red LED
  }
  
  delay(1000); // Delay for 1 second
}