#include <DHT.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <RTClib.h>  // Include the RTC library

#define DHTPIN 2       // DHT22 data pin is connected to digital pin 2
#define DHTTYPE DHT22  // DHT type is DHT22
#define NUM_BARS 5     // Number of bars for graphical representation

DHT dht(DHTPIN, DHTTYPE);

// Set the LCD address to 0x27 for a 20 chars and 4 line display
LiquidCrystal_I2C lcd(0x27, 20, 4);

RTC_DS1307 rtc; // Create an instance of the RTC DS1307 object

unsigned long previousMillis = 0;
const long interval = 1000;  // Interval between updates in milliseconds (5 seconds)

float lastTemperature = 0.0;
float lastHumidity = 0.0;

void setup() {
  Serial.begin(9600);
  lcd.init();                      // Initialize the LCD
  lcd.backlight();                 // Turn on the backlight
  dht.begin();
  
  Wire.begin();  // Initialize I2C communication
  rtc.begin();   // Initialize RTC
  
  // If the RTC isn't running, set it to the time of compilation
  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

void loop() {
  unsigned long currentMillis = millis();  // Current time
  
  // Check if it's time to update
  if (currentMillis - previousMillis >= interval) {
    // Update previousMillis to current time
    previousMillis = currentMillis;
    
    // Read temperature and humidity
    float temperature = dht.readTemperature(); // Read temperature in Celsius
    float humidity = dht.readHumidity(); // Read humidity
    
    // Convert temperature from Celsius to Fahrenheit
    temperature = (temperature * 9 / 5) + 32;
    
    // Read current time from RTC
    DateTime now = rtc.now();
    
    // Check if temperature or humidity has changed
    if (temperature != lastTemperature || humidity != lastHumidity) {
      // Update last temperature and humidity
      lastTemperature = temperature;
      lastHumidity = humidity;
      
      // Clear and update temperature
      lcd.setCursor(0, 0);
      lcd.print("                "); // Clear the line
      lcd.setCursor(0, 0);
      lcd.print("Temp: ");
      lcd.print(temperature);
      lcd.print("F"); // Display temperature in Fahrenheit
      
      // Clear and update humidity
      lcd.setCursor(0, 1);
      lcd.print("                "); // Clear the line
      lcd.setCursor(0, 1);
      lcd.print("Humidity: ");
      lcd.print(humidity);
      lcd.print("%");
    }
    
    // Clear and update current time
    lcd.setCursor(0, 3);
    lcd.print("                "); // Clear the line
    lcd.setCursor(0, 3);
    lcd.print("Time: ");
    lcd.print(now.hour());
    lcd.print(":");
    if (now.minute() < 10) {
      lcd.print("0");
    }
    lcd.print(now.minute());
    lcd.print(":");
    if (now.second() < 10) {
      lcd.print("0");
    }
    lcd.print(now.second());
  }
}