#include <DHT.h>
#include <LiquidCrystal_I2C.h>
#include <ESP32Servo.h>  // Use the ESP32Servo library instead of Servo

// DHT22 sensor setup
#define DHTPIN 14        // Pin where DHT22 is connected (GPIO14)
#define DHTTYPE DHT22    // Define DHT sensor type (DHT22)

// Define pins
#define LED_PIN 13       // Pin for LED
#define SERVO_PIN 12     // Pin for Servo motor control

#define TEMPERATURE_THRESHOLD 5    // Temperature threshold (5°C)
#define HUMIDITY_LOWER_THRESHOLD 85 // Lower bound for RH
#define HUMIDITY_UPPER_THRESHOLD 95 // Upper bound for RH

DHT dht(DHTPIN, DHTTYPE);  // Create DHT object for DHT22 sensor
LiquidCrystal_I2C lcd(0x3F, 16, 2);  // Adjust the I2C address if necessary
Servo fanServo;        // Create Servo object for the fan

unsigned long startTime = 0;  // Timer start
bool timerStarted = false;    // To check if the timer has started

void setup() {
  Serial.begin(9600);

  // Initialize DHT22 sensor
  dht.begin();

  pinMode(LED_PIN, OUTPUT);  // Set LED pin as output
  fanServo.attach(SERVO_PIN);  // Attach the servo to the defined pin using ESP32Servo library

  lcd.init();
  lcd.backlight();
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Temp & Humidity:");

  // Initialize fan (servo) to off
  fanServo.write(0);  // Set servo to 0° (fan off)
  digitalWrite(LED_PIN, LOW); // Turn off the LED
}

void loop() {
  delay(2000); // Delay between readings (adjust as needed)

  // Read temperature and humidity from DHT22 sensor
  float temperature = dht.readTemperature();  // Read temperature in Celsius
  float humidity = dht.readHumidity();        // Read humidity in %

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

  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");

  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  lcd.setCursor(0, 1); // Set cursor to the second line
  lcd.print("                "); // Clear the previous motor speed

  // Logic for fan (servo) control based on temperature and humidity
  if (temperature > TEMPERATURE_THRESHOLD || humidity < HUMIDITY_LOWER_THRESHOLD || humidity > HUMIDITY_UPPER_THRESHOLD) {
    // Start timer only when temperature exceeds 5°C or humidity goes out of range
    if (!timerStarted) {
      startTime = millis();  // Capture the start time
      timerStarted = true;   // Timer is now running
    }

    // Calculate time elapsed since temperature exceeded threshold or humidity went out of range
    unsigned long elapsedTime = (millis() - startTime) / 1000;  // Time in seconds

    // Turn on the fan (servo motor) and LED
    fanServo.write(180);    // Set servo to 180° (fan full speed)
    digitalWrite(LED_PIN, HIGH); // Turn on the LED

    // Display motor status and elapsed time
    lcd.setCursor(0, 1);
    lcd.print("Fan ON");
    lcd.setCursor(8, 1);
    lcd.print("Time: ");
    lcd.print(elapsedTime);
    lcd.print("s");  // Show seconds
  } else {
    // Reset timer if temperature is below 5°C and humidity is within range
    timerStarted = false;
    
    // Turn off the fan (servo motor) and LED
    fanServo.write(0);  // Set servo to 0° (fan off)
    digitalWrite(LED_PIN, LOW); // Turn off the LED
    
    // Display motor status
    lcd.setCursor(0, 1);
    lcd.print("Fan OFF ");
    lcd.setCursor(8, 1);
    lcd.print("                ");  // Clear the time display
  }

  // Display temperature, humidity, and fan speed/strength on the LCD
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temperature);
  lcd.print("C H:");
  lcd.print(humidity);
  lcd.print("%");

  // Calculate and display fan strength as a percentage
  int servoPosition = fanServo.read();  // Get current servo position
  int fanStrength = map(servoPosition, 0, 180, 0, 100);  // Map the servo position (0 to 180) to fan strength (0% to 100%)

  lcd.setCursor(0, 1);
  lcd.print("Fan Strength: ");
  lcd.print(fanStrength);
  lcd.print("%");
}