#define BLYNK_PRINT Serial

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <DHT.h>

char auth[] = "xxxxxxxxxxxxxxxxxxx"; // replace the xxx with your authentication key
char ssid[] = "xxxxx"; // replace xxx with your wifi ssid
char pass[] = "xxxxx"; // replace xxx with your wifi password

#define DHTPIN 2 // connect to pin GPIO 2
#define RELAY_PIN 14 // connect to the pin connected to the relay module (e.g., GPIO 14)
#define LED_PIN 13 // connect to the pin connected to the LED

// I2C LCD configuration
LiquidCrystal_I2C lcd(0x27, 16, 2);

// uncomment the type of sensor you use
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21 // DHT 21, AM2301

DHT dht(DHTPIN, DHTTYPE);

BlynkTimer timer;

// Define temperature thresholds and hysteresis
float temperatureThresholdActivate = 25.0;
float temperatureThresholdDeactivate = 22.0;
float hysteresis = 1.0;

void sendSensor() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Blynk.virtualWrite(V0, t); // Virtual pin 0
  Blynk.virtualWrite(V1, h); // Virtual pin 1

  // Control the simulated exhaust fan (LED) based on temperature thresholds
  if (t > temperatureThresholdActivate) {
    digitalWrite(RELAY_PIN, HIGH); // Activate the simulated fan (LED)
    Serial.println("Exhaust fan activated.");
  } else if (t < temperatureThresholdDeactivate - hysteresis) {
    digitalWrite(RELAY_PIN, LOW); // Deactivate the simulated fan (LED)
    Serial.println("Exhaust fan deactivated.");
  }

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

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

void setup() {
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);
  dht.begin();

  // Initialize LCD
  lcd.begin(16, 2);

  pinMode(RELAY_PIN, OUTPUT); // Set the relay pin as an output
  pinMode(LED_PIN, OUTPUT); // Set the LED pin as an output

  timer.setInterval(10000L, sendSensor); // Setup a function to be called every 10 seconds
}

void loop() {
  Blynk.run();
  timer.run();
}