int8_t piny[]={2,3,4,5,6,7,8,9,10,11};
int8_t pocet_pinov=sizeof(piny)/sizeof(int8_t);
int rychlost;
int i=0;
bool stav=true;
unsigned long previousMillis=0;
void setup() {
  for(int i=0;i<pocet_pinov;i++){
    pinMode(piny[i], OUTPUT);
  }
  Serial.begin(9600);
  Serial.println(pocet_pinov);
}

void loop() {
  rychlost=map(analogRead(A0),0,1023,50,1000);
  Serial.println(rychlost);
  unsigned long currentMillis=millis();
  if(currentMillis-previousMillis>=rychlost){
    previousMillis=currentMillis;
    if(stav){
      digitalWrite(piny[i++], HIGH);
    }
    else{
      digitalWrite(piny[i--], LOW);
    }

    if(i>=pocet_pinov||i<=0)
      stav=!stav;
    //delay(rychlost);
  }
  
}