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

// These are for the clock
#define DS1307_ADDRESS 0x68 //địa chỉ của DS1307 Slave Address (SLA)

// These are for the temperature
#define DHTPIN 2 //Đọc dữ liệu từ DHT11 ở chân 2 trên mạch Arduino
#define DHTTYPE DHT22 //Khai báo loại cảm biến DHT22
#define TIMEDHT 1000 

// Global variables
uint8_t wday, mday, month, year;
uint8_t hours, minutes, seconds;

char szTime[9];    // mm:ss\0

float humidity, celsius;

uint8_t degC[] = { 6, 3, 3, 56, 68, 68, 68 }; // Deg C

uint8_t clear = 0x00;

uint32_t timerDHT = TIMEDHT;

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27,20,4);  // Define LCD 2004 with Address

bool flasher = true;  // nhấp nhay dau 2 cham

void beginDS1307()
{
  // Read the values ​​(date and time) of the DS1307 module
  Wire.beginTransmission(DS1307_ADDRESS);
  Wire.write(clear);
  Wire.endTransmission();
  Wire.requestFrom(DS1307_ADDRESS, 0x07);

  seconds = bcdToDec(Wire.read());
  minutes = bcdToDec(Wire.read());
  hours = bcdToDec(Wire.read() & 0xff);
  wday = bcdToDec(Wire.read());
  mday = bcdToDec(Wire.read());
  month = bcdToDec(Wire.read());
  year = bcdToDec(Wire.read());
}

uint8_t decToBcd(uint8_t value)
{
  return ((value / 10 * 16) + (value % 10));
}

uint8_t bcdToDec(uint8_t value)
{
  return ((value / 16 * 10) + (value % 16));
}


// Code for get Temperature
void getTemperature()
{
  // Wait for a time between measurements
  if ((millis() - timerDHT) > TIMEDHT) {
    // Update the timer
    timerDHT = millis();

    // Reading temperature or humidity takes about 250 milliseconds!
    // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
    humidity = dht.readHumidity();

    // Read temperature as Celsius (the default)
    celsius = dht.readTemperature();


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

// Get a label from PROGMEM into a char array
char *mon2str(uint8_t mon, char *psz, uint8_t len)
{
  static const __FlashStringHelper* str[] =
  {
    F("Jan"), F("Feb"), F("Mar"), F("Apr"),
    F("May"), F("Jun"), F("Jul"), F("Aug"),
    F("Sep"), F("Oct"), F("Nov"), F("Dec")
  };

  strncpy_P(psz, (const char PROGMEM *)str[mon - 1], len);
  psz[len] = '\0';

  return (psz);
}

char *dow2str(uint8_t code, char *psz, uint8_t len)
{
  static const __FlashStringHelper* str[] =
  {
    F("Sunday"), F("Monday"), F("Tuesday"),
    F("Wednesday"), F("Thursday"), F("Friday"),
    F("Saturday")
  };

  strncpy_P(psz, (const char PROGMEM *)str[code - 1], len);

  psz[len] = '\0';

  return (psz);
}

void setup(void)
{
  Wire.begin();
  lcd.init();  
  dht.begin();
}

void lcdClock(void)  //
{
  char szBuf[10];
  lcd.backlight();
  lcd.setCursor(7,0);
  lcd.print(hours); lcd.print((flasher ? ':' : ' ')); 
  lcd.print(minutes);
  flasher = !flasher;
  lcd.setCursor(1,1);
  lcd.print(dow2str(wday,szBuf,sizeof(szBuf) - 1));lcd.print(" ");
  lcd.print(mday);lcd.print("-"); lcd.print(mon2str(month, szBuf, sizeof(szBuf) - 1));
  lcd.print("-");  lcd.print(year +2000);
  lcd.setCursor(0,2);
  lcd.print("--------------------");
  lcd.setCursor(0,3);
  lcd.print("T:");lcd.print(celsius);lcd.print(" C");
  lcd.setCursor(11,3);
  lcd.print("H:");lcd.print(humidity); lcd.print("\%");
   
}

void loop(void)
{
  static uint32_t lastTime = 0; // Memory (ms)
  static uint8_t  display = 0;  // Current display mode    Được dùng để tạo ngắt Timer

  beginDS1307();
  getTemperature();
  if ((millis() - lastTime) >= 1000)
      {
        lastTime = millis();
        lcdClock();
        
      }
  
}