#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

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

LiquidCrystal_I2C lcd(0x27, 20, 4);

int sec=0;
int count;
unsigned long t1;

void clk()
{
  if(sec<59)
    sec++;
  else
    sec=0;
  lcd.setCursor(0,2);
  lcd.print(sec);
  lcd.print(" ");
}
void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  Timer1.initialize(1000000);
  Timer1.attachInterrupt(clk);
}

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

  if (key != NO_KEY) {
    //Serial.println(key);
    lcd.setCursor(0,0);
    lcd.print(key);
  }
 /* if(count>=100)
  {
  if(sec<59)
    sec++;
  else
    sec=0;
  lcd.setCursor(0,2);
  lcd.print(sec);
  lcd.print(" ");
  count=1;
  t1=micros();
  }
  else
    count++;*/
//delay(100);
//delayMicroseconds(9765);
//Serial.println(micros()-t1);
}