#include <Wire.h>                     // Library for I2C communication
#include <LiquidCrystal_I2C.h>         // Library for LCD I2C control
#include "DHT.h"                      // Library for DHT22 sensor
#include <RTClib.h>                   // Library for DS1307 RTC

#define DHTPIN 13                      // Define the pin for the DHT22 sensor (connected to pin 13)
#define DHTTYPE DHT22                  // Define the type of DHT sensor (DHT22)

DHT dht(DHTPIN, DHTTYPE);              // Initialize the DHT sensor on pin 13 as a DHT22 type

// Set the I2C address for the LCD (0x27 is a common address for LCD2004 I2C displays)
LiquidCrystal_I2C lcd(0x27, 20, 4);    // Initialize the LCD object with I2C address and dimensions (20x4)

RTC_DS1307 rtc;                        // Create an RTC object for DS1307

void setup() {
  lcd.init();                          // Initialize the LCD
  lcd.backlight();                     // Turn on the LCD backlight

  dht.begin();                         // Initialize the DHT sensor

  if (!rtc.begin()) {                  // Initialize the RTC
    lcd.print("Couldn't find RTC");    // Error message if RTC is not found
    while (1);                         // Stop the program if there's no RTC
  }

  if (!rtc.isrunning()) {              // Check if the RTC is running
    lcd.print("RTC is NOT running!");  // Display warning if RTC is not running
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));  // Set RTC to the time of code compilation
  }

  lcd.setCursor(0, 0);                 // Set cursor to the first line, first character (0, 0)
  lcd.print("Initializing...");        // Print initial message on the LCD
  delay(2000);                         // Wait for 2 seconds to show the message
}

void loop() {
  DateTime now = rtc.now();            // Get the current date and time from the RTC
  float humidity = dht.readHumidity();   // Read the humidity from the DHT22 sensor
  float temperature = dht.readTemperature(); // Read the temperature from the DHT22 sensor

  lcd.clear();                          // Clear the display

  // Display the date and time on the first line (convert year to B.E.)
  lcd.setCursor(0, 0);
  lcd.print(now.day(), DEC);            // Print the day
  lcd.print('/');
  lcd.print(now.month(), DEC);          // Print the month
  lcd.print('/');
  lcd.print(now.year() + 543, DEC);     // Print the year in B.E. (พ.ศ.) by adding 543
  lcd.print(" ");
  lcd.print(now.hour(), DEC);           // Print the hour
  lcd.print(':');
  lcd.print(now.minute(), DEC);         // Print the minute

  // Display the temperature and humidity on the second line
  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temperature);               // Print the temperature value
  lcd.print(" C");

  lcd.setCursor(0, 2);
  lcd.print("Humidity: ");
  lcd.print(humidity);                  // Print the humidity value
  lcd.print(" %");

  delay(2000);                          // Wait for 2 seconds before the next reading
}