int pin[8] = {9,8,7,6,5,4,3,2};
uint8_t  k;// main value
unsigned long saved_millis;// just saving millis
void setup() {

  Serial.begin(115200);

  for(int i = 0 ; i <= 8; i++){
    pinMode(pin[i], OUTPUT); //set pin 2-9 as output
  }
}

void loop() {
  if(millis() - saved_millis > 250){
    saved_millis = millis();      // simpli counting
    Serial.println(k);
    k++;
  }
  
  for(int i = 0; i <= 8; i++){
    bool bita = k & (0x80 >> i);  //
    digitalWrite(pin[i],bita);
  }

}