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

// Pin Definitions
int Input = A0;
int R_LED = 2;
int G_LED = 3;
int Buzzer = 4;

// VAL INTEGER
int val;
int MAX = 400;

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 columns, 2 rows

void setup() {
  Serial.begin(9600);  // Serial Monitor setup
  pinMode(Input, INPUT);
  pinMode(R_LED, OUTPUT);
  pinMode(G_LED, OUTPUT);
  pinMode(Buzzer, OUTPUT);

  lcd.begin(16, 2);  // Initialize LCD
  lcd.backlight();  // Turn on the backlight

  // Welcome message
  lcd.setCursor(0, 0);
  lcd.print("Gas Detector");
  delay(2000);  // Show the welcome message for 2 seconds
  lcd.clear();  // Clear the display
}

void loop() {
  val = analogRead(Input);  // Read the sensor value

  if (val >= MAX) {
    digitalWrite(R_LED, HIGH);  // Turn on red LED
    digitalWrite(Buzzer, HIGH);  // Turn on buzzer
    digitalWrite(G_LED, LOW);   // Turn off green LED

    // Display GAS LEAKING message
    lcd.clear();  // Clear previous message
    lcd.setCursor(0, 0);
    lcd.print("GAS LEAKING");
    Serial.println("GAS LEAKING");
  } else {
    digitalWrite(R_LED, LOW);   // Turn off red LED
    digitalWrite(Buzzer, LOW);  // Turn off buzzer
    digitalWrite(G_LED, HIGH);  // Turn on green LED

    // Display NORMAL message with fade effect
    lcd.clear();  // Clear previous message
    lcd.setCursor(0, 0);
    lcd.print("Normal Status");
    Serial.println("Normal");
  }

  delay(3000);  // Delay for 3 seconds to prevent frequent updates
}