byte ledPins[] = {15, 2, 4, 5, 18, 19, 21, 12, 26, 25};
int ledDelay;
int direction = 1;
int currentLED = 0;
unsigned long changeTime;
int potPin = 13;

void setup() {
  for (int x=0; x<10; x++)
  {
    pinMode(ledPins[x], OUTPUT);
  }
   changeTime = millis();
   Serial.begin(115200);
}

void loop() {
  ledDelay = analogRead(potPin)/4.095;
  Serial.println(ledDelay);

  if((millis() - changeTime) > ledDelay) {
    changeLED();
    changeTime = millis();
  }
}
void changeLED() {
  for (int x=0; x<10; x++)
  {
    digitalWrite(ledPins[x], LOW);
  }
  digitalWrite(ledPins[currentLED], HIGH);
  currentLED += direction;

  if (currentLED == 9)
  {
    direction = -1;
  }
  if (currentLED == 0){
    direction = 1;
  }
}