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

#define DHTPIN 2        
#define DHTTYPE DHT22     

DHT dht(DHTPIN, DHTTYPE);
Servo fanServo;
LiquidCrystal_I2C lcd(0x27, 16, 2); 

const int fanNormalSpeed = 90;  
const int fanHighSpeed = 180;   

float temperatureThreshold = 30.0; 

void setup() {
  Serial.begin(9600);  
  dht.begin();
  fanServo.attach(3);  

  lcd.init();                      
  lcd.backlight();                 
  lcd.setCursor(0, 0);
  lcd.print("Fan Speed: Normal"); 
}

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

  
  if (isnan(temperature)) {
    lcd.setCursor(0, 1);
    lcd.print("Error reading DHT!");
    Serial.println("Error reading DHT!");  
    delay(2000);
    lcd.clear();
  } else {
    lcd.setCursor(0, 1);
    lcd.print("Temp: ");
    lcd.print(temperature);
    lcd.print(" C");

   
    if (temperature > temperatureThreshold) {
      fanServo.write(fanHighSpeed);
      lcd.setCursor(0, 0);
      lcd.print("Fan Speed: High  ");
    } else {
      fanServo.write(fanNormalSpeed);
      lcd.setCursor(0, 0);
      lcd.print("Fan Speed: Normal");
    }
  }

  delay(2000);  
}