#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
#include <TimerOne.h>

const uint8_t ROWS = 4;
const uint8_t COLS = 3;
char keys[ROWS][COLS] = {
  { '1', '2', '3'},
  { '4', '5', '6'},
  { '7', '8', '9'},
  { '*', '0', '#' }
};

uint8_t colPins[COLS] = { 5, 4, 3}; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 }; // Pins connected to R1, R2, R3, R4

//1物件名稱 2角位 3
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

LiquidCrystal_I2C lcd(0X27, 20, 4);

int sec = 0;
bool _update = false;


void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  Timer1.initialize(1000000); //每隔多久
  Timer1.attachInterrupt(clock); //執行函式
  
}

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

  if (key != NO_KEY) {
    lcd.setCursor(0, 0);
    lcd.print(key);
  }
  if(_update)//如果_update是true就印出秒數
  {
  lcd.setCursor(0, 2);
  lcd.print(sec);
  lcd.print(" ");
  _update = false;
  }
}

void clock()
{
  if (sec < 59)
    sec++;
  else
    sec = 0;
  _update = true;
}