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

// Pin Definitions
#define DHTPIN 4 // 


#define I2C_SDA 21 
#define I2C_SCL 22 

DHT dht(DHTPIN, DHT22);


LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  
  Serial.begin(115200);


  dht.begin();

  
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Air Quality Monitoring");
}

void loop() {
 
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Simulate gas value (replace with your logic)
  int gasValue = random(0, 2000); // Simulate random gas values

  // Display temperature and humidity on LCD
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C");

  lcd.setCursor(0, 1);
  lcd.print("Humidity: ");
  lcd.print(humidity);
  lcd.print("%");

  lcd.setCursor(0, 0);
  lcd.print("Gas Level: ");
  lcd.print(gasValue);

  
  if (gasValue < 300) {
    lcd.setCursor(0, 0);
    lcd.print("Gas Level: Good");
  } else if (gasValue < 800) {
    lcd.setCursor(0, 0);
    lcd.print("Gas Level: Moderate");
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Gas Level: High");
  }

  delay(6000); 
  lcd.clear();
}