#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);


int minuty = 0;
int sekundy = 0;
int ktore = 0; // 0=m  1=s
bool test1 = true;
bool test2 = true;

void setup()
{
  DDRB &= ~(1<<1);
  PORTB |= 1<<1;
  DDRB &= ~(1<<0);
  PORTB |= 1<<0;

  lcd.init();
  lcd.backlight();
  lcd.print(String(minuty) + ":" + String(sekundy));
  lcd.setCursor(0, 1);
  lcd.print("min");
}

void loop()
{
    if( (PINB&(1<<0)) == 0 && test1 == true  )
    {
      test1 = false;
      if(ktore == 0) // zmena na prvom riadku
      {
        minuty++;
        lcd.home();
        lcd.print(String(minuty) + ":" + String(sekundy));
      }
      else
      {
        sekundy++;
        lcd.home();
        lcd.print(String(minuty) + ":" + String(sekundy));
      }
    }
  	if( (PINB&(1<<0)) != 0 && test1 != true  )
    {
      test1 = true;
    }
  
    if( (PINB&(1<<1)) == 0 && test2 == true ) // prepnutie druhého riadku
    {
      test2 = false;
      if(ktore == 0)
      {
        ktore = 1;
        lcd.setCursor(0, 1);
        lcd.print("sek");
      }
      else
      {
        ktore = 0;
        lcd.setCursor(0, 1);
        lcd.print("min");
      }
 
    }
 	if( (PINB&(1<<1)) != 0 && test2 != true  )
    {
      test2 = true;
    }
}