const int ledPins[8] = {13, 12, 14, 27, 26, 25, 33, 32};
const int potPin = 34;

int currentLed = 0;

void setup() {
  for (int i = 0; i < 8; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
  pinMode(potPin, INPUT);
  digitalWrite(ledPins[currentLed], HIGH);
}

void loop() {
  int potValue = analogRead(potPin);


  if (potValue >= 1900 && potValue <= 2200) {
    return;
  }

  int delayTime;
  int direction;

  if (potValue < 1900) {

    direction = -1;
    delayTime = map(potValue, 0, 1899, 20, 400);
  } else {

    direction = 1;
    delayTime = map(potValue, 2201, 4095, 400, 20);
  }

  for (int i = 0; i < 8; i++) {
    digitalWrite(ledPins[i], LOW);
  }
  digitalWrite(ledPins[currentLed], HIGH);

  delay(delayTime);

  currentLed += direction;
  if (currentLed >= 8) currentLed = 0;
  if (currentLed < 0)  currentLed = 7;
}