// https://forum.arduino.cc/t/binary-counter-led-project-issue/1438696
//

int ledPin[4] = {10, 11, 12, 13};
const int loopDelay = 577;

int loopCounter = 0;

//bool writeValueLed[4];

int numArray[4][8] = {
  {0, 2, 4, 6, 8, 10, 12, 14},
  {0, 1, 4, 5, 8, 9, 12, 13},
  {0, 1, 2, 3, 8, 9, 10, 11},
  {0, 1, 2, 3, 4, 5, 6, 7}
};

// for use in digital read and write
const bool OFF = false;
const auto ON = true;

void setup() {
  Serial.begin(115200);
  Serial.println("\nwhat does it do?\n");

  for (byte ii = 0; ii < 4; ii++)
    pinMode(ledPin[ii], OUTPUT);

}

void loop() {
  static unsigned long lastTime = millis() - loopDelay;
  unsigned long now = millis();

  if (now - lastTime < loopDelay) return;   // not time for next step
  lastTime += loopDelay;

  Serial.print("loopCounter = ");
  Serial.println(loopCounter);
 
  for (byte theBit = 0; theBit < 4; theBit++) {
    bool onOrOff = true;  // unless proven otherwise
    for (int i = 0; i < 8; i++) { 
      if (numArray[theBit][i] == loopCounter) {
        onOrOff = false;
        break;
      }
    }
    digitalWrite(ledPin[theBit], onOrOff ? ON : OFF);
  }

  loopCounter++;
  if (loopCounter >= 16) loopCounter = 0;
}


/*


  for (byte ii = 0; ii < 16; ii++) {




  }
*/