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

#define DHTPIN 15
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int PUMP_RELAY_PIN = 18;  // Relay for the pump
const int FAN_RELAY_PIN = 19;   // Relay for the fan

float lower = 23;  // Lower temperature threshold
const float upper = 27;  // Upper temperature threshold

const float lowerHumidity = 40.0;  // Lower humidity threshold
const float upperHumidity = 60.0;  // Upper humidity threshold

void setup() {
  Serial.begin(115200);
  delay(1000);
  Serial.println(F("DHT22 !"));
  dht.begin();

  lcd.init();
  lcd.backlight();
  lcd.print("DHT22 Sensor");

  pinMode(PUMP_RELAY_PIN, OUTPUT);  // Set pump relay pin as output
  pinMode(FAN_RELAY_PIN, OUTPUT);   // Set fan relay pin as output
}

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

  // Check if the sensor readings are valid
  if (isnan(temperature) || isnan(humidity)) {  // If the readings are not a number (NaN)
    Serial.println(F("Failed to read from DHT sensor!"));  // Print an error message
    lcd.clear();  // Clear the LCD
    lcd.print("Sensor Error");  // Display an error message on the LCD
  } else {
    // Display the temperature and humidity on the LCD
    lcd.clear();  // Clear the LCD
    lcd.setCursor(0, 0);  // Set the cursor to the first row, first column
    lcd.print("Temp: ");
    lcd.print(temperature);  // Display the temperature on the LCD
    lcd.print(" C");
    
    lcd.setCursor(0, 1);  // Set the cursor to the second row, first column
    lcd.print("Humidity: ");
    lcd.print(humidity);  // Display the humidity on the LCD
    lcd.print(" %");

    // Control the fan based on the temperature
    if (temperature > upper) {  // If the temperature is above the upper threshold (27°C)
      Serial.println("Hott");
      Serial.println("Turning on fan");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Hott");
      lcd.setCursor(0, 1);
      lcd.print("Turning on fan");
      digitalWrite(FAN_RELAY_PIN, HIGH);  // Turn on the relay (activate fan or cooling system)
    } else if (temperature < lower) {  // If the temperature is below the lower threshold (23°C)
      Serial.println("Cold");
      Serial.println("Turning off fan");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Cold");
      lcd.setCursor(0, 1);
      lcd.print("Turning off fan");
      digitalWrite(FAN_RELAY_PIN, LOW);  // Turn off the relay (deactivate fan or cooling system)
    }

    // Control the pump based on the humidity
    if (humidity > upperHumidity) {  // If the humidity is above 60%
      Serial.println("Humidity high");
      Serial.println("Turning off pump");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Humidity high");
      lcd.setCursor(0, 1);
      lcd.print("Turning off pump");
      digitalWrite(PUMP_RELAY_PIN, LOW);  // Turn off pump (deactivate water supply)
    } else if (humidity < lowerHumidity) {  // If the humidity is below 40%
      Serial.println("Humidity low");
      Serial.println("Turning on pump");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Humidity low");
      lcd.setCursor(0, 1);
      lcd.print("Turning on pump");
      digitalWrite(PUMP_RELAY_PIN, HIGH);  // Turn on pump (activate water supply)
    }
  }

  delay(3000);  // Wait for 1 second before the next loop iteration
}