/* Charlieplexing example: 3 pins driving 6 LEDs. */

#define ROWS 3
#define COLS 2
byte LED_PINS[] = { 2, 3, 4 };
const byte LED_PIN_COUNT = sizeof(LED_PINS);
bool ledState[ROWS][COLS];

void clearMatrix(bool matrix[ROWS][COLS]) {
  for(int i = 0; i < ROWS; i++) {
    for(int j = 0; j < COLS; j++) {
      matrix[i][j] = false;
    }
  }
}

void displayLEDMatrix(bool matrix[ROWS][COLS], int ms) {
  byte k = 0;
  unsigned long startMillis = millis();
  while(millis() - startMillis < ms) {
    for(byte i = 0; i < LED_PIN_COUNT; i++) {
      for(byte j = 0; j < LED_PIN_COUNT; j++) {
          if(i != j) {
            if(matrix[i][j>i ? j-1 : j]) {
              //Serial.println(String()+"Pin "+i+" is HIGH and pin "+j+" is low");
              pinMode(LED_PINS[i], OUTPUT);
              pinMode(LED_PINS[j], OUTPUT);
              digitalWrite(LED_PINS[i], HIGH);
              digitalWrite(LED_PINS[j], LOW);

              // Keep LED on for 1 milliseconds:
              delay(1);

              pinMode(LED_PINS[i], INPUT);
              pinMode(LED_PINS[j], INPUT);
            }
          }
      }
    }
  }

  clearMatrix(matrix);
}

void setup() {
  Serial.begin(9600);
}

void loop() {
  bool ledPattern[ROWS][COLS] = {false};
  ledPattern[0][0] = true;
  ledPattern[1][0] = true;
  ledPattern[2][0] = true;
  displayLEDMatrix(ledPattern, 500);

  ledPattern[0][1] = true;
  ledPattern[1][1] = true;
  ledPattern[2][1] = true;
  displayLEDMatrix(ledPattern, 500);
}