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

#define DHTPIN 7        // Digital pin connected to the DHT sensor
#define DHTTYPE DHT22   // Change to DHT22 if you're using that type of sensor


#define TEMP_THRESHOLD 25.0  // Temperature threshold for greenhouse (adjust as needed)

#define LED_PIN 4           // Digital pin connected to the LED



// Initialize DHT sensor
DHT dht(DHTPIN, DHTTYPE);

// Initialize LCD screen with I2C address 0x27
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  
  // Initialize DHT sensor
  dht.begin();
  
// Initialize LCD screen
  lcd.init();
  lcd.backlight();

  lcd.setCursor(1,0);
  lcd.print("Temperature ");

  lcd.setCursor(0, 1);
  lcd.print("Monitoring System");

  // Initialize LED pin as an output
  pinMode(LED_PIN, OUTPUT);
   
}

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

  // Check if any reads failed and exit early (to try again)
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Print temperature and humidity to serial monitor
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print("%  Temperature: ");
  Serial.print(temperature);
  Serial.println("°C");

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

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

// Check if temperature exceeds threshold
  if (temperature > TEMP_THRESHOLD) {
    // Display danger message on LCD
    lcd.setCursor(0, 1);
    lcd.print("Danger! Temp > ");
    lcd.print(TEMP_THRESHOLD);
    lcd.print(" C");
    
    // Blink LED for emergency indication
    blinkLED();
  }
  
  
  // Delay between readings
  delay(5000);  // Adjust delay time as needed
}

void blinkLED() {
  // Blink LED for emergency indication
  for (int i = 0; i < 3; i++) {
    digitalWrite(LED_PIN, HIGH);  // Turn LED on
    delay(500);                    // Wait for 500 milliseconds
    digitalWrite(LED_PIN, LOW);   // Turn LED off
    delay(500);                    // Wait for 500 milliseconds
  }
}