const int pinDS = 3;
const int pinSTCP = 4;
const int pinSHCP = 2;
uint16_t cislo = 1234;
unsigned long previousMillis=0;
    

const uint8_t cifry[] = {
    0b00000011,
    0b10011111,
    0b00100101,
    0b00001101,
    0b10011001,
    0b01001001,
    0b01000001,
    0b00011111,
    0b00000001,
    0b00001001,
    0b11111111
};

uint8_t segment[] = {1, 2, 4, 8};

void setup() {
  pinMode(pinDS, OUTPUT);
  pinMode(pinSTCP, OUTPUT);
  pinMode(pinSHCP, OUTPUT);


}

void loop() {
  unsigned long currentMillis = millis();
   zobrazCislicu(cislo);
  if(currentMillis - previousMillis >= 1000){
    previousMillis = currentMillis;
      cislo = (cislo + 1) % 10;
    }
  }



void zobrazCislicu(int cislo){
  for(int i = 0; i<4; i++){
    uint8_t cifra = cislo%10;
    cislo /=10;
  digitalWrite(pinSTCP, LOW);
  shiftOut(pinDS, pinSHCP, LSBFIRST, cifry[cifra]);
  shiftOut(pinDS, pinSHCP, MSBFIRST, segment[i]);
  digitalWrite(pinSTCP, HIGH);
  }
  
}