关于arduino驱动的****8光立方的一些问题，感谢大家抽出时间看我的问题，如果能详细回答的话不胜感激。

由于是自己探索，基本刚刚起步学习，算是基本没有学过系统的知识，而且时间比较紧迫，有些问题实在没办法解决，希望能得到大家的帮助，谢谢！

首先，在用arduino驱动的光立方中能不能不使用电阻？
其次，我在一个视频中看到他利用了三极管做每层的开关，请问这个是必要的吗，而且这些开关起到什么作用？
最后，请问能不能帮我讲解一些下面的代码各部分的具体含义和效果功能。
再次感谢！

#include

#define XAXIS 0
#define YAXIS 1
#define ZAXIS 2

#define POS_X 0
#define NEG_X 1
#define POS_Z 2
#define NEG_Z 3
#define POS_Y 4
#define NEG_Y 5

#define BUTTON_PIN 8
#define RED_LED 5
#define GREEN_LED 7

#define TOTAL_EFFECTS 8
#define RAIN 0
#define PLANE_BOING 1
#define SEND_VOXELS 2
#define WOOP_WOOP 3
#define CUBE_JUMP 4
#define GLOW 5
#define TEXT 6
#define LIT 7

#define RAIN_tiME 260
#define PLANE_BOING_TIME 220
#define SEND_VOXELS_TIME 140
#define WOOP_WOOP_TIME 350
#define CUBE_JUMP_TIME 200
#define GLOW_TIME 8
#define TEXT_TIME 300
#define CLOCK_TIME 500

#define REMAIN_TIME 25000

//uint8_t characters[10][8] = {
//  {0x3C, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x3C}, //0
//  {0x10, 0x18, 0x14, 0x10, 0x10, 0x10, 0x10, 0x3C}, //1
//  {0x3C, 0x42, 0x40, 0x40, 0x3C, 0x02, 0x02, 0x7E}, //2
//  {0x3C, 0x40, 0x40, 0x3C, 0x40, 0x40, 0x42, 0x3C}, //3
//  {0x22, 0x22, 0x22, 0x22, 0x7E, 0x20, 0x20, 0x20}, //4
//  {0x7E, 0x02, 0x02, 0x3E, 0x40, 0x40, 0x42, 0x3C}, //5
//  {0x3C, 0x02, 0x02, 0x3E, 0x42, 0x42, 0x42, 0x3C}, //6
//  {0x3C, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40}, //7
//  {0x3C, 0x42, 0x42, 0x3C, 0x42, 0x42, 0x42, 0x3C}, //8
//  {0x3C, 0x42, 0x42, 0x42, 0x3C, 0x40, 0x40, 0x3C}, //9
//};

//uint8_t characters[10][8] = {{0x1C,0x22,0x22,0x22,0x22,0x22,0x22,0x1C},//0
//{0x08,0x18,0x08,0x08,0x08,0x08,0x08,0x1C},//1
//{0x1C,0x22,0x02,0x02,0x1C,0x20,0x20,0x3E},//2
//{0x1C,0x22,0x02,0x1C,0x02,0x02,0x22,0x1C},//3
//{0x08,0x18,0x28,0x48,0x7C,0x08,0x08,0x08},//4
//{0x3E,0x20,0x20,0x3E,0x02,0x02,0x22,0x1C},//5
//{0x1C,0x22,0x20,0x3C,0x22,0x22,0x22,0x1C},//6
//{0x3E,0x02,0x04,0x08,0x10,0x10,0x10,0x10},//7
//{0x1C,0x22,0x22,0x1C,0x22,0x22,0x22,0x1C},//8
//{0x1C,0x22,0x22,0x22,0x1E,0x02,0x22,0x1C},//9
//};

uint8_t characters[40][8]={{0x1C,0x22,0x22,0x22,0x22,0x22,0x22,0x1C},//0
{0x08,0x18,0x08,0x08,0x08,0x08,0x08,0x1C},//1
{0x1C,0x22,0x02,0x02,0x1C,0x20,0x20,0x3E},//2
{0x1C,0x22,0x02,0x1C,0x02,0x02,0x22,0x1C},//3
{0x08,0x18,0x28,0x48,0x7C,0x08,0x08,0x08},//4
{0x3E,0x20,0x20,0x3E,0x02,0x02,0x22,0x1C},//5
{0x1C,0x22,0x20,0x3C,0x22,0x22,0x22,0x1C},//6
{0x3E,0x02,0x04,0x08,0x10,0x10,0x10,0x10},//7
{0x1C,0x22,0x22,0x1C,0x22,0x22,0x22,0x1C},//8
{0x1C,0x22,0x22,0x22,0x1E,0x02,0x22,0x1C},//9
{0x00,0x1C,0x22,0x22,0x22,0x3E,0x22,0x22},//A
{0x00,0x3C,0x22,0x22,0x3E,0x22,0x22,0x3C},//B
{0x00,0x1C,0x22,0x20,0x20,0x20,0x22,0x1C},//C
{0x00,0x3C,0x22,0x22,0x22,0x22,0x22,0x3C},//D
{0x00,0x3E,0x20,0x20,0x3E,0x20,0x20,0x3E},//E
{0x00,0x3E,0x20,0x20,0x3E,0x20,0x20,0x20},//F
{0x00,0x1C,0x22,0x20,0x3E,0x22,0x22,0x1C},//G
{0x00,0x22,0x22,0x22,0x3E,0x22,0x22,0x22},//H
{0x00,0x1C,0x08,0x08,0x08,0x08,0x08,0x1C},//I
{0x00,0x3E,0x08,0x08,0x08,0x08,0x28,0x18},//J
{0x00,0x20,0x2C,0x30,0x20,0x30,0x2C,0x20},//K
{0x00,0x20,0x20,0x20,0x20,0x20,0x20,0x3E},//L
{0x00,0x42,0x66,0x5A,0x42,0x42,0x42,0x42},//M
{0x00,0x00,0x2C,0x32,0x22,0x22,0x22,0x22},//n
{0x00,0x1C,0x22,0x22,0x22,0x22,0x22,0x1C},//O
{0x00,0x3C,0x22,0x22,0x3C,0x20,0x20,0x20},//P
{0x00,0x1C,0x22,0x22,0x22,0x2A,0x26,0x1F},//Q
{0x00,0x38,0x24,0x24,0x38,0x30,0x28,0x24},//R
{0x00,0x1C,0x22,0x20,0x1C,0x02,0x22,0x1C},//S
{0x00,0x3E,0x08,0x08,0x08,0x08,0x08,0x08},//T
{0x00,0x42,0x42,0x42,0x42,0x42,0x42,0x3C},//U
{0x00,0x22,0x22,0x22,0x14,0x14,0x08,0x00},//V
{0x00,0x41,0x41,0x49,0x55,0x55,0x63,0x41},//W
{0x00,0x00,0x42,0x24,0x18,0x18,0x24,0x42},//X
{0x00,0x22,0x22,0x14,0x08,0x10,0x20,0x00},//Y
{0x00,0x3E,0x02,0x04,0x08,0x10,0x20,0x3E},//Z
};

char *str="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

uint8_t BitReverseTable256[] =
{
  0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
  0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
  0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
  0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
  0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
  0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
  0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
  0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
  0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
  0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
  0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
  0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
  0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
  0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
  0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
  0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
};

uint8_t cube[8][8];
uint8_t currentEffect;

uint16_t timer;

uint64_t randomTimer;

bool loading;

bool loopMode;

uint64_t loopTimer;

void setup() {
  Serial.begin(2000000);
  loading = true;
  loopMode = true;
  randomTimer = 0;
  currentEffect = RAIN;

  SPI.begin();
  SPI.beginTransaction(SPISettings(8000000, MSBFIRST, SPI_MODE0));

  pinMode(BUTTON_PIN, INPUT_PULLUP);
//  pinMode(RED_LED, OUTPUT);
//  pinMode(GREEN_LED, OUTPUT);

  randomSeed(analogRead(0));
  digitalWrite(GREEN_LED, HIGH);

}

void loop() {
  //Serial.println("start loop");
  randomTimer++;
  loopTimer++;
  if(loopMode){
    if (currentEffect >= TOTAL_EFFECTS) {
      currentEffect = 0;
    }
    if(loopTimer>REMAIN_TIME){
      loopTimer=0;
      clearCube();
      loading = true;
      timer = 0;
      currentEffect++;
      randomSeed(randomTimer);
      randomTimer = 0;
      delay(100);
    }
  }

  if (digitalRead(BUTTON_PIN) == LOW) {
    clearCube();
    loading = true;
    timer = 0;
    currentEffect++;
    if(loopMode){
      currentEffect=0;
    }
    loopMode=false;
    if (currentEffect >= TOTAL_EFFECTS) {
      currentEffect = 100;
      loopMode=true;
      loopTimer=0;
    }
    randomSeed(randomTimer);
    randomTimer = 0;
//    digitalWrite(RED_LED, HIGH);
//    digitalWrite(GREEN_LED, LOW);
    delay(500);
//    digitalWrite(RED_LED, LOW);
//    digitalWrite(GREEN_LED, HIGH);
  }

  switch (currentEffect) {
    case RAIN: rain(); break;
    case PLANE_BOING: planeBoing(); break;
    case SEND_VOXELS: sendVoxels(); break;
    case WOOP_WOOP: woopWoop(); break;
    case CUBE_JUMP: cubeJump(); break;
    case GLOW: glow(); break;
    case TEXT: text("YANGGENGBABA"); break;
    case LIT: lit(); break;

//    default: rain();
  }
//  Serial.print("currentEffect:");
//  Serial.println(currentEffect);

  if(currentEffect>=0){
    renderCube();
  }

}

void renderCube() {
  for (uint8_t i = 0; i < 8; i++) {
    digitalWrite(SS, LOW);
    SPI.transfer(0x01 << i);
    for (uint8_t j = 0; j < 8; j++) {
      SPI.transfer(cube[j]);
    }
    digitalWrite(SS, HIGH);
  }
}

void rain() {
  if (loading) {
    clearCube();
    loading = false;
  }
  timer++;
  if (timer > RAIN_TIME) {
    timer = 0;
    shift(NEG_Y);
    uint8_t numDrops = random(0, 5);
    for (uint8_t i = 0; i < numDrops; i++) {
      setVoxel(random(0, 8), 7, random(0, 8));
    }
  }
}

uint8_t planePosition = 0;
uint8_t planeDirection = 0;
bool looped = false;

void planeBoing() {
  if (loading) {
    clearCube();
    uint8_t axis = random(0, 3);
    planePosition = random(0, 2) * 7;
    setPlane(axis, planePosition);
    if (axis == XAXIS) {
      if (planePosition == 0) {
        planeDirection = POS_X;
      } else {
        planeDirection = NEG_X;
      }
    } else if (axis == YAXIS) {
      if (planePosition == 0) {
        planeDirection = POS_Y;
      } else {
        planeDirection = NEG_Y;
      }
    } else if (axis == ZAXIS) {
      if (planePosition == 0) {
        planeDirection = POS_Z;
      } else {
        planeDirection = NEG_Z;
      }
    }
    timer = 0;
    looped = false;
    loading = false;
  }

  timer++;
  if (timer > PLANE_BOING_TIME) {
    timer = 0;
    shift(planeDirection);
    if (planeDirection % 2 == 0) {
      planePosition++;
      if (planePosition == 7) {
        if (looped) {
          loading = true;
        } else {
          planeDirection++;
          looped = true;
        }
      }
    } else {
      planePosition--;
      if (planePosition == 0) {
        if (looped) {
          loading = true;
        } else {
          planeDirection--;
          looped = true;
        }
      }
    }
  }
}

uint8_t selX = 0;
uint8_t selY = 0;
uint8_t selZ = 0;
uint8_t sendDirection = 0;
bool sending = false;

void sendVoxels() {

  if (loading) {
//    Serial.println("loading sendVoxels");
    clearCube();
    for (uint8_t x = 0; x < 8; x++) {
      for (uint8_t z = 0; z < 8; z++) {
        setVoxel(x, random(0, 2) * 7, z);
      }
    }
    loading = false;
    selX = 0;
    selY = 0;
    selZ = 0;
    sendDirection = 0;
    sending = false;
  }

  timer++;
  if (timer > SEND_VOXELS_TIME) {
    timer = 0;
    if (!sending) {
      selX = random(0, 8);
      selZ = random(0, 8);
      if (getVoxel(selX, 0, selZ)) {
        selY = 0;
        sendDirection = POS_Y;
      } else if (getVoxel(selX, 7, selZ)) {
        selY = 7;
        sendDirection = NEG_Y;
      }
      sending = true;
    } else {
      if (sendDirection == POS_Y) {
        selY++;
        setVoxel(selX, selY, selZ);
        clearVoxel(selX, selY - 1, selZ);
        if (selY == 7) {
          sending = false;
        }
      } else {
        selY--;
        setVoxel(selX, selY, selZ);
        clearVoxel(selX, selY + 1, selZ);
        if (selY == 0) {
          sending = false;
        }
      }
    }
  }
}

uint8_t cubeSize = 0;
bool cubeExpanding = true;

void woopWoop() {
  if (loading) {
    clearCube();
    cubeSize = 2;
    cubeExpanding = true;
    loading = false;
  }

  timer++;
  if (timer > WOOP_WOOP_TIME) {
    timer = 0;
    if (cubeExpanding) {
      cubeSize += 2;
      if (cubeSize == 8) {
        cubeExpanding = false;
      }
    } else {
      cubeSize -= 2;
      if (cubeSize == 2) {
        cubeExpanding = true;
      }
    }
    clearCube();
    drawCube(4 - cubeSize / 2, 4 - cubeSize / 2, 4 - cubeSize / 2, cubeSize);
  }
}

uint8_t xPos;
uint8_t yPos;
uint8_t zPos;

void cubeJump() {
  if (loading) {
    clearCube();
    xPos = random(0, 2) * 7;
    yPos = random(0, 2) * 7;
    zPos = random(0, 2) * 7;
    cubeSize = 8;
    cubeExpanding = false;
    loading = false;
  }

  timer++;
  if (timer > CUBE_JUMP_TIME) {
    timer = 0;
    clearCube();
    if (xPos == 0 && yPos == 0 && zPos == 0) {
      drawCube(xPos, yPos, zPos, cubeSize);
    } else if (xPos == 7 && yPos == 7 && zPos == 7) {
      drawCube(xPos + 1 - cubeSize, yPos + 1 - cubeSize, zPos + 1 - cubeSize, cubeSize);
    } else if (xPos == 7 && yPos == 0 && zPos == 0) {
      drawCube(xPos + 1 - cubeSize, yPos, zPos, cubeSize);
    } else if (xPos == 0 && yPos == 7 && zPos == 0) {
      drawCube(xPos, yPos + 1 - cubeSize, zPos, cubeSize);
    } else if (xPos == 0 && yPos == 0 && zPos == 7) {
      drawCube(xPos, yPos, zPos + 1 - cubeSize, cubeSize);
    } else if (xPos == 7 && yPos == 7 && zPos == 0) {
      drawCube(xPos + 1 - cubeSize, yPos + 1 - cubeSize, zPos, cubeSize);
    } else if (xPos == 0 && yPos == 7 && zPos == 7) {
      drawCube(xPos, yPos + 1 - cubeSize, zPos + 1 - cubeSize, cubeSize);
    } else if (xPos == 7 && yPos == 0 && zPos == 7) {
      drawCube(xPos + 1 - cubeSize, yPos, zPos + 1 - cubeSize, cubeSize);
    }
    if (cubeExpanding) {
      cubeSize++;
      if (cubeSize == 8) {
        cubeExpanding = false;
        xPos = random(0, 2) * 7;
        yPos = random(0, 2) * 7;
        zPos = random(0, 2) * 7;
      }
    } else {
      cubeSize--;
      if (cubeSize == 1) {
        cubeExpanding = true;
      }
    }
  }
}

bool glowing;
uint16_t glowCount = 0;

void glow() {
  if (loading) {
    clearCube();
    glowCount = 0;
    glowing = true;
    loading = false;
  }

  timer++;
  if (timer > GLOW_TIME) {
    timer = 0;
    if (glowing) {
      if (glowCount < 448) {
        do {
          selX = random(0, 8);
          selY = random(0, 8);
          selZ = random(0, 8);
        } while (getVoxel(selX, selY, selZ));
        setVoxel(selX, selY, selZ);
        glowCount++;
      } else if (glowCount < 512) {
        lightCube();
        glowCount++;
      } else {
        glowing = false;
        glowCount = 0;
      }
    } else {
      if (glowCount < 448) {
        do {
          selX = random(0, 8);
          selY = random(0, 8);
          selZ = random(0, 8);
        } while (!getVoxel(selX, selY, selZ));
        clearVoxel(selX, selY, selZ);
        glowCount++;
      } else {
        clearCube();
        glowing = true;
        glowCount = 0;
      }
    }
  }
}

uint8_t charCounter = 0;
uint8_t charPosition = 0;

void text(char string[]) {
  uint8_t len=strlen(string);
  if (loading) {
    clearCube();
    charPosition = -1;
    charCounter = 0;
    loading = false;
  }
  timer++;
  if (timer > TEXT_TIME) {
    timer = 0;

    shift(NEG_Z);
    charPosition++;

    if (charPosition == 7) {
      charCounter++;
      if (charCounter > len - 1) {
        charCounter = 0;
      }
      charPosition = 0;
    }

    if (charPosition == 0) {
      for (uint8_t i = 0; i < 8; i++) {
        //cube[0] = BitReverseTable256[characters[string[charCounter] - '0'] & 0xff];
        char *pch =strchr(str,string[charCounter]);
        cube[0] = BitReverseTable256[characters[(int)(pch-str)] & 0xff];
      }
    }
  }
}

void lit() {
  if (loading) {
    clearCube();
    for(uint8_t i=0; i<8; i++) {
      for(uint8_t j=0; j<8; j++) {
        cube[j] = 0xFF;
      }
    }
    loading = false;
  }
}

void setVoxel(uint8_t x, uint8_t y, uint8_t z) {
  cube[7 - y][7 - z] |= (0x01 << x);
}

void clearVoxel(uint8_t x, uint8_t y, uint8_t z) {
  cube[7 - y][7 - z] ^= (0x01 << x);
}

bool getVoxel(uint8_t x, uint8_t y, uint8_t z) {
  return (cube[7 - y][7 - z] & (0x01 << x)) == (0x01 << x);
}

void setPlane(uint8_t axis, uint8_t i) {
  for (uint8_t j = 0; j < 8; j++) {
    for (uint8_t k = 0; k < 8; k++) {
      if (axis == XAXIS) {
        setVoxel(i, j, k);
      } else if (axis == YAXIS) {
        setVoxel(j, i, k);
      } else if (axis == ZAXIS) {
        setVoxel(j, k, i);
      }
    }
  }
}

void shift(uint8_t dir) {

  if (dir == POS_X) {
    for (uint8_t y = 0; y < 8; y++) {
      for (uint8_t z = 0; z < 8; z++) {
        cube[y][z] = cube[y][z] << 1;
      }
    }
  } else if (dir == NEG_X) {
    for (uint8_t y = 0; y < 8; y++) {
      for (uint8_t z = 0; z < 8; z++) {
        cube[y][z] = cube[y][z] >> 1;
      }
    }
  } else if (dir == POS_Y) {
    for (uint8_t y = 1; y < 8; y++) {
      for (uint8_t z = 0; z < 8; z++) {
        cube[y - 1][z] = cube[y][z];
      }
    }
    for (uint8_t i = 0; i < 8; i++) {
      cube[7] = 0;
    }
  } else if (dir == NEG_Y) {
    for (uint8_t y = 7; y > 0; y--) {
      for (uint8_t z = 0; z < 8; z++) {
        cube[y][z] = cube[y - 1][z];
      }
    }
    for (uint8_t i = 0; i < 8; i++) {
      cube[0] = 0;
    }
  } else if (dir == POS_Z) {
    for (uint8_t y = 0; y < 8; y++) {
      for (uint8_t z = 1; z < 8; z++) {
        cube[y][z - 1] = cube[y][z];
      }
    }
    for (uint8_t i = 0; i < 8; i++) {
      cube[7] = 0;
    }
  } else if (dir == NEG_Z) {
    for (uint8_t y = 0; y < 8; y++) {
      for (uint8_t z = 7; z > 0; z--) {
        cube[y][z] = cube[y][z - 1];
      }
    }
    for (uint8_t i = 0; i < 8; i++) {
      cube[0] = 0;
    }
  }
}

void drawCube(uint8_t x, uint8_t y, uint8_t z, uint8_t s) {
  for (uint8_t i = 0; i < s; i++) {
    setVoxel(x, y + i, z);
    setVoxel(x + i, y, z);
    setVoxel(x, y, z + i);
    setVoxel(x + s - 1, y + i, z + s - 1);
    setVoxel(x + i, y + s - 1, z + s - 1);
    setVoxel(x + s - 1, y + s - 1, z + i);
    setVoxel(x + s - 1, y + i, z);
    setVoxel(x, y + i, z + s - 1);
    setVoxel(x + i, y + s - 1, z);
    setVoxel(x + i, y, z + s - 1);
    setVoxel(x + s - 1, y, z + i);
    setVoxel(x, y + s - 1, z + i);
  }
}

void lightCube() {
  for (uint8_t i = 0; i < 8; i++) {
    for (uint8_t j = 0; j < 8; j++) {
      cube[j] = 0xFF;
    }
  }
}

void clearCube() {
  for (uint8_t i = 0; i < 8; i++) {
    for (uint8_t j = 0; j < 8; j++) {
      cube[j] = 0;
    }
  }
}