#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <RTClib.h>
RTC_DS1307 rtc;
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
LiquidCrystal_I2C lcd(0x27, 20, 4);
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
int Buzzer = 11;
void setup() 
{
  Serial.begin(57600);
  Wire.begin();

  lcd.init();
  lcd.backlight();
  lcd.home();
  lcd.setCursor(0,1);
  lcd.print("User Number:");
  lcd.setCursor(0,2);
  lcd.print("T:");
  lcd.setCursor(9,2);
  lcd.print("V:");
  lcd.setCursor(0,3);
  lcd.print("%DRC:");
  lcd.blink();
  lcd.setCursor(19,1);

  pinMode(Buzzer,OUTPUT);
  pinMode(A0,INPUT);
  pinMode(A1,INPUT);
  digitalWrite(Buzzer,HIGH);
  
      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!");
      }
}
void loop() 
{
  char key = keypad.getKey();

  if (key != NO_KEY) 
  {
    lcd.print(key);
    lcd.setCursor(19,1);
    beep();
  }
  Time();
}
void beep()
{
  digitalWrite(Buzzer,LOW);
  delay(50);
  digitalWrite(Buzzer, HIGH);
}
/*void Temp()
{
  int analogValue = analogRead(A0);
  float temp = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
lcd.setCursor(2,2);
lcd.print(temp);
lcd.print("C");
lcd.print(" ");
}
void Volt()
{
  int val=analogRead(A1);
  float volt;
  volt =((val/1023.0)*5.0);
  lcd.setCursor(11,2);
  lcd.print(volt);
  lcd.print("V");
  lcd.print(" ");
}*/
void Time()
{
  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(") ");
    lcd.setCursor(19,1);
    //delay(5000);
}