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

// Pin definitions
#define DHT_PIN 15
#define DHT_TYPE DHT22
#define MQ5_PIN 34

// Setup DHT sensor
DHT dht(DHT_PIN, DHT_TYPE);

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

void setup() {
  Serial.begin(115200);
  dht.begin();
  
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("SweetHertz IoT");
  delay(2000);
  lcd.clear();
}

void loop() {
  // Read DHT22
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Read MQ-5 (analog, 0–4095 on ESP32)
  int gasRaw = analogRead(MQ5_PIN);
  
  // Check for DHT read errors
  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("DHT read error!");
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error!   ");
    delay(2000);
    return;
  }

  // Print to Serial Monitor
  Serial.print("Temp: "); Serial.print(temperature); Serial.println(" C");
  Serial.print("Humidity: "); Serial.print(humidity); Serial.println(" %");
  Serial.print("Gas (raw): "); Serial.println(gasRaw);

  // Display on LCD
  lcd.setCursor(0, 0);
  lcd.print("T:"); lcd.print(temperature, 1); lcd.print("C ");
  lcd.print("H:"); lcd.print(humidity, 0); lcd.print("%");

  lcd.setCursor(0, 1);
  lcd.print("Gas: "); lcd.print(gasRaw); lcd.print("     ");

  delay(2000);
}