knightrider.ino

int pins[] = {7, 8, 9, 10, 11, 12, 13};
int pinsLength = sizeof(pins) / sizeof(int);

void setup() {
  for (int pin = 0; pin < pinsLength; pin++) {
    pinMode(pins[pin], OUTPUT);
  }
}

void loop() {

  for (int pin = 0; pin < pinsLength; pin++) {
    fadeLedOn(pins[pin]);
  }

  for (int pin = 0; pin < pinsLength; pin++) {
    fadeLedOff(pins[pin]);
  }


  for (int pin = pinsLength-1; pin >= 0; pin--) {
    fadeLedOn(pins[pin]);
  }

  for (int pin = pinsLength-1; pin >= 0; pin--) {
    fadeLedOff(pins[pin]);
  }

  delay(100);
}

void fadeLedOn(int pin) {
  for (int i = 0; i < 256; i+=10) {
    analogWrite(pin, i);
    delay(1);
  }
}

void fadeLedOff(int pin) {
  for (int i = 255; i > 0; i-=10) {
    analogWrite(pin, i);
    delay(1);
  }
}