#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd = LiquidCrystal_I2C(0x27,20,4);

boolean btnUp=false;
boolean btnDown=false;
boolean btnSelect=false;
int arrowPosition=0;

void setup() {
// Serial
 Serial.begin(9600);

// Display setup
  lcd.init();
  lcd.backlight();
  lcd.clear();

// Menu seetup
lcd.setCursor(3,0);
lcd.print("1 dioda blika");
lcd.setCursor(3,1);
lcd.print("2 diody blikaju");
lcd.setCursor(3,2);
lcd.print("3 diody blikaju");
lcd.setCursor(3,3);
lcd.print("4 diody blikaju");

lcd.setCursor(0,0);
lcd.print(">");

// Pin setup

DDRB &=~(1<<1);
DDRB &=~(1<<2);
DDRB &=~(1<<3);

PORTB |=1<<1;
PORTB |=1<<2;
PORTB |=1<<3;

DDRD |= (1 << 2) | (1 << 3) | (1 << 4) | (1 << 5); 
}

void loop() {

menuSelector();
}


void menuSelector(){
  if((PINB&(1<<1)) !=0 && btnUp !=true){
    btnUp=true;
  }
  if((PINB&(1<<1)) ==0 && btnUp ==true){
    btnUp=false;
    arrowPosition=arrowPosition + 1;
    
    if(arrowPosition>3){
    arrowPosition=0;
    }

    lcd.setCursor(0,arrowPosition-1);
    lcd.print("   ");
    lcd.setCursor(0,arrowPosition);
    lcd.print(">");
  }


  if((PINB&(1<<3)) !=0 && btnDown !=true){
    btnDown=true;
  }
  if((PINB&(1<<3)) ==0 && btnDown ==true){
    btnDown=false;
    arrowPosition=arrowPosition - 1;

   if(arrowPosition<0){
    arrowPosition=3;
    }
    lcd.setCursor(0,arrowPosition+1);
    lcd.print("   ");
    lcd.setCursor(0,arrowPosition);
    lcd.print(">");
  }

  if((PINB&(1<<2)) !=0 && btnSelect !=true){
    btnSelect=true;
  }
  if((PINB&(1<<2)) ==0 && btnSelect ==true){
    btnSelect=false;
    lightLed();
  }
}

void lightLed(){
  unlight();
  switch (arrowPosition) {
    case 0: PORTD |= (1 << 2); break; 
    case 1: PORTD |= (1 << 2) | (1 << 3); break; 
    case 2: PORTD |= (1 << 2) | (1 << 3) | (1 << 4); break;
    case 3: PORTD |= (1 << 2) | (1 << 3) | (1 << 4) | (1 << 5); break; 
  }
}

void unlight(){
  PORTD &= ~(1 << 2);
  PORTD &= ~(1 << 3);
  PORTD &= ~(1 << 4);
  PORTD &= ~(1 << 5);
}