const int bit_number = 4;
const int time_const = 1000;
int binary[bit_number];
int bit_array[128][bit_number];

byte look_up16[] = {8, 11, 14, 15, 16, 15, 13, 11, 7, 4, 2, 0, 0, 1, 3, 6};
//byte look_up32 = {16, 19, 22, 25, 27, 29, 31, 32, 32, 32, 31, 30, 28, 26, 23, 20, 17, 14, 11, 8, 6, 4, 2, 1, 0, 0, 1, 2, 3, 6, 8, 11};
//byte look_up64 = {32, 35, 39, 42, 45, 48, 51, 53, 56, 58, 60, 61, 62, 63, 64, 64, 64, 63, 62, 61, 60, 58, 56, 53, 51, 48, 45, 42, 39, 35, 32, 29, 25, 22, 19, 16, 13, 11, 8, 6, 4, 3, 2, 1, 0, 0, 0, 1, 2, 3, 4, 6, 8, 11, 13, 16, 19, 22, 25, 29, 32, 35, 39, 42};
//byte look_up128[] = {64, 67, 71, 74, 77, 81, 84, 87, 90, 93, 96, 99, 102, 104, 107, 109, 112, 114, 116, 118, 119, 121, 122, 124, 125, 126, 127, 127, 128, 128, 128, 128, 128, 127, 127, 126, 125, 124, 122, 121, 119, 118, 116, 114, 112, 109, 107, 104, 102, 99, 96, 93, 90, 87, 84, 81, 77, 74, 71, 67, 64, 61, 57, 54, 51, 47, 44, 41, 38, 35, 32, 29, 26, 24, 21, 19, 16, 14, 12, 10, 9, 7, 6, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 6, 7, 9, 10, 12, 14, 16, 19, 21, 24, 26, 29, 32, 35, 38, 41, 44, 47, 51, 54, 57, 61, 64, 67, 71, 74, 77, 81, 84, 87};

void setup() {
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);

  for (byte i = 0; i < pow(2, bit_number); i++) {
    getDigitalFromInt(look_up16[i]);
    for (byte j = 0; j < bit_number; j++) {
      bit_array[i][j] = binary[j];
    }
  }

}

void loop() { 
  for (byte i = 0; i < pow(2, bit_number); i++) {
    digitalControlUnit(bit_array[i][0], bit_array[i][1], bit_array[i][2], bit_array[i][3]);
    /*, bit_array[i][4], bit_array[i][5], bit_array[i][6]*/
    delay(time_const);
  }  
}

void digitalControlUnit(int b0, int b1, int b2, int b3) {
  //, int b4, int b5, int b6
  if (b0 == 1){
    PORTD |= 1 << 2;
  } else {
    PORTD &= ~(1 << 2);
  }
  if (b1 == 1){
    PORTD |= 1 << 3;
  } else {
    PORTD &= ~(1 << 3);
  }
  if (b2 == 1){
    PORTD |= 1 << 4;
  } else {
    PORTD &= ~(1 << 4);
  }
  if (b3 == 1){
    PORTD |= 1 << 5;
  } else {
    PORTD &= ~(1 << 5);
  }/*
  if (b4 == 1){
    PORTD |= 1 << 6;
  } else {
    PORTD &= ~(1 << 6);
  }
  if (b5 == 1){
    PORTD |= 1 << 7;
  } else {
    PORTD &= ~(1 << 7);
  }
  if (b6 == 1){
    PORTB |= 1 << 0;
  } else {
    PORTB &= ~(1 << 0);
  }*/
}

void getDigitalFromInt(int analog_value) {
  for (byte i = 0; i < bit_number; i++) {
    binary[i] = analog_value % 2;
    analog_value = (analog_value - binary[i])/2;
  }
}