char digit[9] = {0x86,0xDB,0xCF,0x66,0xED,0xFD,0x87,0xFF,0x6F};
int pin[7] = {1,2,3,4,5,6,7};

int idx = random(0,4);
int st = digit[idx];

void setup() {
  DDRD |= 0b11111110;
  DDRB |= 0b11111110;
  PORTB |= 0xFF;
  randomSeed(analogRead(A0));

  izpisi(st);
}

void izpisi(int x){ 
  PORTD = 0b00000001;
  for (int i=0;i<7;i++){
    int stanje = x & 0x01;
    PORTD |= (stanje << pin[i]); // zapise stanje (0/1) na pinu pin[i]
    x >>= 1;
    delay(50);
  }
}

void loop() {
  int stanje_gumba = PINB >> 0 & 0x01;
  
  if(stanje_gumba == 0 && idx != 8){ 
    idx++;
    izpisi(digit[idx]);
  }
  delay(10);

}