byte out1l = 0;  // last 2 digits, and 5 collumns  ddcccccu  ** with digits, if without PNP stage, 0 is on ** - u means unused
byte out1m = 0;  // first 8 digits  dddddddd
byte out1h = 0;  // output to segments abcdefghx - x means decimal point
  // byte order is: out1l, out1m, out1h, all lsb first 
  // D2 to D4 are shift register pins,, d2 - data, d3 - shift clk, d4 - storage clk

  // d5 to d8 are row1 to row4

byte buttonstep = 0;

byte num = 0;

const PROGMEM byte sevseg[] = {0b11111100, 0b01100000, 0b11011010, 0b11110010, 0b01100110, 0b10110110, 0b10111110, 0b11100000, 0b11111110, 0b11110110};

String number = "";

uint16_t cislo = 0;

byte digstep = 0;

void setup() {

  pinMode(2, OUTPUT);  // dtin
  pinMode(3, OUTPUT);  // shclk
  pinMode(4, OUTPUT);  // stclk

  pinMode(5, INPUT_PULLUP);  // r1
  pinMode(6, INPUT_PULLUP);  // r2
  pinMode(7, INPUT_PULLUP);  // r3
  pinMode(8, INPUT_PULLUP);  // r4

  pinMode(9, INPUT_PULLUP);  // double zero

  Serial.begin(9600);

//number = "1";
}

void loop() {

  out1h = (~(pgm_read_byte(&sevseg[cislo])));

  switch(buttonstep % 5) {

    case 4:
    out1l = out1l & 0b11000000;
    out1l = out1l | 0b00111100;
      break;

    case 3:
    out1l = out1l & 0b11000000;
    out1l = out1l | 0b00111010;
      break;

    case 2:
    out1l = out1l & 0b11000000;
    out1l = out1l | 0b00110110;
      break;

    case 1:
    out1l = out1l & 0b11000000;
    out1l = out1l | 0b00101110;
      break;

    case 0:
    out1l = out1l & 0b11000000;
    out1l = out1l | 0b00011110;
      break;

  }

  digitalWrite(4, LOW);
  shiftOut(2, 3, LSBFIRST, out1l);
  shiftOut(2, 3, LSBFIRST, out1m);
  shiftOut(2, 3, LSBFIRST, out1h);
  digitalWrite(4, HIGH);

  if((!(digitalRead(5))) && (buttonstep % 5) == 0) {num = 7;}
  if((!(digitalRead(5))) && (buttonstep % 5) == 1) {num = 8;}
  if((!(digitalRead(5))) && (buttonstep % 5) == 2) {num = 9;}
  if((!(digitalRead(5))) && (buttonstep % 5) == 3) {Serial.println("X/↑");}
  if((!(digitalRead(5))) && (buttonstep % 5) == 4) {Serial.println("S/-");}

  if((!(digitalRead(6))) && (buttonstep % 5) == 0) {num = 4;}
  if((!(digitalRead(6))) && (buttonstep % 5) == 1) {num = 5;}
  if((!(digitalRead(6))) && (buttonstep % 5) == 2) {num = 6;}
  if((!(digitalRead(6))) && (buttonstep % 5) == 3) {Serial.println("PLU");}
  if((!(digitalRead(6))) && (buttonstep % 5) == 4) {Serial.println("%");}

  if((!(digitalRead(7))) && (buttonstep % 5) == 0) {num = 1;}
  if((!(digitalRead(7))) && (buttonstep % 5) == 1) {num = 2;}
  if((!(digitalRead(7))) && (buttonstep % 5) == 2) {num = 3;}
  if((!(digitalRead(7))) && (buttonstep % 5) == 3) {Serial.println("A2");}
  if((!(digitalRead(7))) && (buttonstep % 5) == 4) {Serial.println("ST");}

  if((!(digitalRead(8))) && (buttonstep % 5) == 0) {Serial.println("C/on ");}
  if((!(digitalRead(8))) && (buttonstep % 5) == 1) {num = 0;}
  if((!(digitalRead(8))) && (buttonstep % 5) == 2) {Serial.println("#/off");}
  if((!(digitalRead(8))) && (buttonstep % 5) == 3) {Serial.println("A1");}
  if((!(digitalRead(8))) && (buttonstep % 5) == 4) {Serial.println("Tl");}

  if((!(digitalRead(9)))) {Serial.println("00");}

  buttonstep = buttonstep + 1;

  if(num < 250) {
    delay(500);
    number += num;
    num = 252;
    return;
  }

  switch(digstep) {

    case 0:
      out1m = 0b10000000;
      break;

    case 1:
      out1m = 0b01000000;
      break;

    case 2:
      out1m = 0b00100000;
      break;

    case 3:
      out1m = 0b00010000;
      break;

    case 4:
      out1m = 0b00001000;
      break;

    case 5:
      out1m = 0b00000100;
      break;

    case 6:
      out1m = 0b00000010;
      break;

    case 7:
      out1m = 0b00000001;
      out1h = out1h | 1;
      break;

    case 8:
      out1l = out1l & 0b00111111;
      out1l = out1l | 0b10000000;
      out1h = out1h & 0b11111110;
      break;

    case 9:
      out1l = out1l & 0b00111111;
      out1l = out1l | 0b01000000;
      break;

  }
byte addr = digstep;
  cislo = ((number[(addr)]) - 48);

digstep = digstep + 1;
digstep = digstep % 10;
}