// LCD I2C library
#include <LiquidCrystal_I2C.h>

// DHT22 Temperature and Humidity sensor library
#include <DHT.h>

// LCD setup: I2C address 0x27, 16 columns, 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Constants
#define DHTPIN 2          // Pin connected to DHT22 sensor
#define DHTTYPE DHT22     // Sensor type: DHT22
DHT dht(DHTPIN, DHTTYPE); // Initialize the sensor

// Variables
float humidity;
float temperature;
int buzzer = 12; // Buzzer connected to pin 12

// Initialization of LCD, sensor, and buzzer
void setup() {
  lcd.init();
  lcd.backlight();
  dht.begin();
  pinMode(buzzer, OUTPUT);

  Serial.begin(9600);
  Serial.println("Temperature and Humidity Monitoring System Initialized");

  // Setup pins for LEDs (if used)
  pinMode(9, OUTPUT);  // LED1
  pinMode(10, OUTPUT); // LED2
  pinMode(11, OUTPUT); // LED3
}

void loop() {
  delay(2000); // Wait for sensor to stabilize

  // Read humidity and temperature
  humidity = dht.readHumidity();
  temperature = dht.readTemperature();

  // Display values in Serial Monitor
  Serial.print("Current Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

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

  // Condition 1: Both humidity > 70% and temperature > 30°C
  if (humidity >= 70.0 && temperature >= 30.0) {
    digitalWrite(9, HIGH);  // Turn on warning LED
    digitalWrite(10, LOW);
    digitalWrite(11, LOW);

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Warning: Hot &");
    lcd.setCursor(0, 1);
    lcd.print("Humid Conditions");

    // Buzzer alert pattern
    for (int i = 0; i < 2; i++) {
      digitalWrite(buzzer, 1); tone(buzzer, 900, 100); delay(400);
      digitalWrite(buzzer, 0); tone(buzzer, 900, 100); delay(400);
    }

  } 
  // Condition 2: Both humidity and temperature are in normal range
  else if (humidity < 70.0 && temperature < 30.0) {
    digitalWrite(9, LOW);
    digitalWrite(10, LOW);
    digitalWrite(11, HIGH);  // Normal status LED

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Temp & Humidity");
    lcd.setCursor(0, 1);
    lcd.print("Within Normal");
    digitalWrite(buzzer, 0);
  }

  // Condition 3: Temperature too high only
  else if (humidity < 70.0 && temperature >= 30.0) {
    digitalWrite(9, LOW);
    digitalWrite(10, HIGH);
    digitalWrite(11, LOW);

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alert: Temp High");
    lcd.setCursor(0, 1);
    lcd.print("Check Cooling");

    digitalWrite(buzzer, 1); tone(buzzer, 400, 400); delay(400);
    digitalWrite(buzzer, 0); tone(buzzer, 400, 400); delay(400);
  }

  // Condition 4: Humidity too high only
  else if (humidity >= 70.0 && temperature < 30.0) {
    digitalWrite(9, LOW);
    digitalWrite(10, HIGH);
    digitalWrite(11, LOW);

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alert: Humidity");
    lcd.setCursor(0, 1);
    lcd.print("Too High!");

    digitalWrite(buzzer, 1); tone(buzzer, 400, 400); delay(400);
    digitalWrite(buzzer, 0); tone(buzzer, 400, 400); delay(400);
  }
}