int pins[] = {PB2, PB1, PB0, PB4, PB3, PB5};

void setup() {
  // put your setup code here, to run once:
  for (int n=0; n<6; n++) {
    pinMode(pins[n], OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  static int currect_pin = 0;
  static int previous_pin = 0;
  digitalWrite(pins[previous_pin], LOW);
  digitalWrite(pins[currect_pin], HIGH);
  previous_pin = currect_pin;
  currect_pin = (++currect_pin) % 6;
  delay(100);
}