void setup() {
  // put your setup code here, to run once:
  DDRC = B11111111; // Pins 30 to 37
  Serial.begin(9600);
}

void printBits(byte number, int bits) {
  String numString = String(number, BIN);
  while (numString.length() < bits) {
    numString = "0" + numString;
  }
  Serial.println(numString);
}

void setBits(byte number, int bits) {
  printBits(number, bits);
  PORTC = number;
}

int parseBitAmount(int bitsAmount) {
  if (bitsAmount > 8) {
    Serial.println("Bits amount not supported! Bits set to 8");
    bitsAmount = 8;
  }
  return bitsAmount;
}


void loop() {
  // put your main code here, to run repeatedly:
  static int bits = 0;
  static byte currentNumber = B0;
  static long lastDelay = millis();
  static int wantedDelayMS = 1000;

  while (!bits) {
    if (lastDelay + 1000 < millis()) {
      Serial.println("No bits amount set! Please input desired amount of bits!");
      lastDelay = millis();
    }

    if (Serial.available()) {
      bits = parseBitAmount(Serial.parseInt());
      Serial.print(bits);
      Serial.println(" set as desired bits!");
      Serial.print("Using pins 2 to ");
      Serial.print(1+bits);
      Serial.println(" to output numbers as binary");
      Serial.println("");
      Serial.println("You can change desired amount of bits by writing       : b<number>");
      Serial.println("And change the delay between bits as millis by writing : d<number>");
    }
  }

  if (Serial.available()) {
    int command = Serial.read();
    if (command == 'b') {
      Serial.println("New byte value given!");
      bits = parseBitAmount(Serial.parseInt());
      Serial.print(bits);
      Serial.println(" bits is now set as the new amount!");
    }
    else if (command == 'd') {
      Serial.println("New delay value given!");
      wantedDelayMS = Serial.parseInt();
      Serial.print("The new delay is now ");
      Serial.print(wantedDelayMS);
      Serial.println(" Millis!");
    }
  }

  if (lastDelay + wantedDelayMS < millis()) {

    setBits(currentNumber, bits);

    currentNumber ++;
    if (currentNumber > pow(2,bits)) {
      currentNumber = 0;
    }
    lastDelay = millis();
  }
}