/* Charlieplexing example: 9 pins driving 72 LEDs. */

#define SCAN_DELAY 300

byte LED_PINS[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13};
const byte LED_PIN_COUNT = sizeof(LED_PINS);

void setup() {
}

void loop() {
  for (byte i = 0; i < LED_PIN_COUNT; i++) {
    for (byte j = 0; j < LED_PIN_COUNT; j++) {
      if (i != j) {
        pinMode(LED_PINS[i], OUTPUT);
        pinMode(LED_PINS[j], OUTPUT);
        digitalWrite(LED_PINS[i], LOW);
        digitalWrite(LED_PINS[j], HIGH);
        delay(SCAN_DELAY);
        pinMode(LED_PINS[i], INPUT);
        pinMode(LED_PINS[j], INPUT);
      }
    }
  }
}