// Date and time functions using a DS1307 RTC connected via I2C and Wire lib
#include "RTClib.h"
#include <Wire.h>
#include "LiquidCrystal_I2C.h"
#include <Keypad.h>
RTC_DS1307 rtc;
LiquidCrystal_I2C lcd(0x27, 20, 4);
const float BETA = 3950;
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};
uint8_t colPins[COLS] = { 5, 4, 3, 2 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 }; // Pins connected to R1, R2, R3, R4
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
void setup () 
{lcd.blink();
  Serial.begin(57600);
  Wire.begin();
/*#ifndef ESP8266
  while (!Serial); // wait for serial port to connect. Needed for native USB
#endif*/
  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    abort();
  }

  if (! rtc.isrunning()) 
  {
    Serial.println("RTC is NOT running, let's set the time!");
  }
  lcd.init();
  lcd.backlight();
  lcd.setCursor(5,1);
}

void loop () 
{
  char key = keypad.getKey();

  if (key != NO_KEY) 
  {
    lcd.print(key);
    lcd.setCursor(5,1);
  }
    DateTime now = rtc.now();
    lcd.setCursor( 0,0);
    lcd.print(now.year(), DEC);
    lcd.print('/');
    lcd.print(now.month(), DEC);
    lcd.print('/');
    lcd.print(now.day(), DEC);
    lcd.print(" (");;
    lcd.print(now.hour(), DEC);
    lcd.print(':');
    lcd.print(now.minute(), DEC);
    lcd.print(':');
    lcd.print(now.second(), DEC);
    lcd.print(") ");
    //delay(3000);
}