#include <LiquidCrystal.h>
LiquidCrystal lcd(13,12,11,10,9,8);

#define set1(r,b) r |= 1<<b    //funkcie na nastavoanie 1 alebo 0
#define set0(r,b) r&= ~(1<<b)

void setup() {
  lcd.begin(16,2);
  Serial.begin(9600);

  DDRD &= ~(1<<2); //btns
  PORTD |= 1<<2;
  DDRD &= ~(1<<3);
  PORTD |= 1<<3;

  //attachPinToInterrupt cez registre pre INT0
  EIMSK |= 1<<INT0; //povedanie ze ktory interrupt
  SREG |= 1<<7;  //zapnutie globalneho istica
  EICRA |= 1<<ISC01; //nastavenie ci falling alebo rising
  EICRA &= ~(1<<ISC00); 

  //pre INT1
  EIMSK |= 1<<INT1;
  SREG |= 1<<7;
  EICRA |= 1<<ISC11;
  EICRA &= ~(1<<ISC10);
}

//global int
int a = 0;

void loop() {
  // put your main code here, to run repeatedly:

}

ISR(INT0_vect) //funckia priradena k interrupt 0
{
  if(a<10)
  {
    a++;
    lcd.clear();
    lcd.print(a);
  }
}

ISR(INT1_vect) //funnkcia priradena k interrupt 1
{
  if(a>0)
  {
    a--;
    lcd.clear();
    lcd.print(a);
  }
}