#include <LiquidCrystal.h> //import lcd library
  #include <Keypad.h> //import keypad library

  LiquidCrystal lcd(5, 4, 3, 2, 1, 0); //lcd pins
  const byte ROWS = 4; // four rows
  const byte COLS = 3; // three columns

  int latchPin = A5;  //Pin connected to ST_CP of 74HC595
  int clockPin = A2;  //Pin connected to SH_CP of 74HC595
  int dataPin = A1;  ////Pin connected to DS of 74HC595

  char keys [ROWS] [COLS] = {
     {'1', '2', '3'},
     {'4', '5', '6'},
     {'7', '8', '9'},
     {'X', '0', 'o'} };

  byte rowPins[ROWS] = {9 ,8 ,7 ,6}; //connect keypad ROW1, ROW2, ROW3, ROW4 to these arduino pins
  byte colPins[COLS] = {13, 12, 11}; //connect keypad COL1, COL2, COL3 to these arduino pins

  //create the keypad
  Keypad myKeypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

  //variables declaration
  String num1, num2;
  int ans;

  void setup(){

  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);

  //set lcd welcome screen
  lcd.begin(16,2);
  lcd.setCursor(2,0);
  lcd.print("vloz hodnotu");
  lcd.setCursor(3,1);
  lcd.print("el. odporu");

}

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

    if (key != NO_KEY && (key == '1' || key == '2' || key == '3' || key == '4' || key == '5' || key == '6' || key == '7' || key == '8' || key == '9' || key == '0')){
          num1 = num1 + key;
          int numLength = num1.length();
          lcd.clear();

          ans = num1.toInt(); //from strings to integer

	  switch (ans)
	  {
		case 1:
		  ans = 0b00000001;
		break;

		case 2:
		  ans = 0b00000010;
		break;

		// atd.
	  }

          lcd.print(ans); //print answer

 //Ans je vlastne hodnota z klavesnice. Ak ans=2 tak sa ledky sa rozsvietia v poradi 01000000 (cize ide o prevod do bin. kodu)
 //tuto by som potreboval predefinovat, resp. priradit hodnote z klavesnice inu binarnu hodnotu. Skusal som vytvarat matice hodnot ale nic.

    digitalWrite(latchPin, LOW);
    shiftOut(dataPin, clockPin, LSBFIRST, ans);  // problem bude mozno ze musis posielat ako MSBFIRST
    digitalWrite(latchPin, HIGH);



     }
    }