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

// Pin Definitions
#define DHTPIN 4       
#define DHTTYPE DHT22    

#define RED_LED 18      
#define BLUE_LED 17      
#define BUZZER 27

// Initialize DHT sensor
DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
    Serial.begin(115200);
    
    pinMode(RED_LED, OUTPUT);
    pinMode(BLUE_LED, OUTPUT);
    pinMode(BUZZER, OUTPUT);

    lcd.init()
    lcd.backlight();
    
    dht.begin();
}

void loop() {
    float temp = dht.readTemperature(); // Get temperature (Celsius)
    float hum = dht.readHumidity();     // Get humidity

    if (isnan(temp) || isnan(hum)) {
        Serial.println("Failed to read from DHT22 sensor!");
        return;
    }

    // Print values to Serial Monitor
    Serial.print("Temperature: ");
    Serial.print(temp);
    Serial.print("°C  Humidity: ");
    Serial.print(hum);
    Serial.println("%");

    // Display on LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(temp);
    lcd.print("C");

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

    // LED and LCD Message Conditions
    if (temp > 30) {
        lcd.setCursor(0, 1);
        lcd.print("Hot! Turn on Fan");
        digitalWrite(RED_LED, HIGH);
        digitalWrite(BLUE_LED, LOW);
    } 
    else if (temp < 20) {
        lcd.setCursor(0, 1);
        lcd.print("Cold! Turn on Heater");
        digitalWrite(RED_LED, LOW);
        digitalWrite(BLUE_LED, HIGH);
    } 
    else {
        lcd.setCursor(0, 1);
        lcd.print("Temperature Normal");
        digitalWrite(RED_LED, LOW);
        digitalWrite(BLUE_LED, LOW);
    }

    // Buzzer Alert if temp > 40°C
    if (temp > 40) {
        tone(BUZZER, 1000);
    } else {
        noTone(BUZZER);
    }

    delay(2000); // Update every 2 seconds
}