8*32的ws2812b点阵屏用arduino实现滚动字幕

实现步骤如下：

1. 安装 FastLED 库。在 Arduino IDE 中，选择“工具”->“库管理器”，搜索“FastLED”并安装。

2. 定义 LED 点阵的布局。对于 8x32 的点阵，可以定义一个 2D 数组，如下所示：

#define NUM_ROWS 8
#define NUM_COLS 32

CRGB leds[NUM_ROWS][NUM_COLS];

3. 在 setup() 函数中初始化 LED 点阵。调用 FastLED 库的 addLeds() 函数，并传入 LED 类型、数据引脚和 LED 数量。

FastLED.addLeds<WS2812B, DATA_PIN, GRB>(leds[0], NUM_ROWS * NUM_COLS);

4. 在 loop() 函数中，实现滚动字幕的效果。可以使用一个字符串数组来存储要显示的文本内容，然后在循环中移动字符串的位置，并将每个字符渲染成对应的 LED 颜色。

char text[] = "Hello, world!";
int text_len = strlen(text);

for (int i = 0; i < text_len + NUM_COLS; i++) {
  // 清空点阵
  FastLED.clear();

  // 计算当前文本的起始位置
  int start_pos = max(0, i - NUM_COLS);

  // 渲染文本
  for (int col = 0; col < NUM_COLS; col++) {
    int char_pos = start_pos + col;
    if (char_pos < text_len) {
      char c = text[char_pos];
      render_char(c, col);
    }
  }

  // 显示点阵
  FastLED.show();

  // 等待一段时间
  delay(50);
}

5. 实现 render_char() 函数，用于将一个字符渲染成对应的 LED 颜色。可以使用一个字符映射表来定义每个字符对应的颜色。

void render_char(char c, int col) {
  // 字符映射表
  const char* chars[] = {
    " 0123456789",
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
    "abcdefghijklmnopqrstuvwxyz",
    "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
  };
  int num_char_sets = sizeof(chars) / sizeof(char*);
  int char_set = -1;
  int char_pos = -1;
  for (int i = 0; i < num_char_sets; i++) {
    const char* pos = strchr(chars[i], c);
    if (pos != NULL) {
      char_set = i;
      char_pos = pos - chars[i];
      break;
    }
  }
  if (char_set < 0 || char_pos < 0) {
    return;
  }

  // 渲染字符
  for (int row = 0; row < NUM_ROWS; row++) {
    if ((char_set * NUM_ROWS + row) >= NUM_COLORS) {
      break;
    }
    leds[row][col] = color_table[char_set * NUM_ROWS + row][char_pos];
  }
}

6. 定义一个颜色映射表，用于定义每个字符在 LED 点阵中的颜色。可以使用一个 2D 数组来定义，如下所示：

#define NUM_COLORS 128

CRGB color_table[NUM_COLORS][8] = {
  // ' ' (空格)
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },

  // '0'-'9'
  { CRGB::Red, CRGB::Green, CRGB::Blue, CRGB::Yellow, CRGB::Purple, CRGB::Cyan, CRGB::Orange, CRGB::White },
  { CRGB::White, CRGB::Green, CRGB::White, CRGB::White, CRGB::White, CRGB::White, CRGB::White, CRGB::White },
  { CRGB::Red, CRGB::Green, CRGB::Red, CRGB::Yellow, CRGB::Green, CRGB::Red, CRGB::Red, CRGB::Yellow },
  { CRGB::Red, CRGB::Green, CRGB::Blue, CRGB::Yellow, CRGB::Green, CRGB::Blue, CRGB::Red, CRGB::White },
  { CRGB::Purple, CRGB::Purple, CRGB::Purple, CRGB::Yellow, CRGB::Purple, CRGB::Yellow, CRGB::Purple, CRGB::Purple },
  { CRGB::Red, CRGB::Green, CRGB::Blue, CRGB::Yellow, CRGB::Green, CRGB::Blue, CRGB::Red, CRGB::White },
  { CRGB::Red, CRGB::Green, CRGB::Blue, CRGB::Yellow, CRGB::Green, CRGB::Blue, CRGB::Red, CRGB::White },
  { CRGB::Red, CRGB::Green, CRGB::Blue, CRGB::Yellow, CRGB::Green, CRGB::Blue, CRGB::Red, CRGB::White },

  // 'A'-'Z'
  { CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Yellow, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red },
  { CRGB::Red, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Red, CRGB::Green, CRGB::Green, CRGB::Green },
  { CRGB::Purple, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Purple },
  { CRGB::Red, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Red },
  { CRGB::Purple, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Purple },
  { CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Yellow },
  { CRGB::Purple, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Purple },
  { CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Yellow },
  { CRGB::Red, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Red },
  { CRGB::Purple, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Purple },
  { CRGB::Red, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Red },
  { CRGB::Purple, CRGB::Purple, CRGB::Purple, CRGB::Purple, CRGB::Purple, CRGB::Purple, CRGB::Purple, CRGB::Purple },
  { CRGB::White, CRGB::White, CRGB::White, CRGB::White, CRGB::White, CRGB::White, CRGB::White, CRGB::White },
  { CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue },
  { CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green },

  // 'a'-'z'
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black },
  { CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black, CRGB::Black }
};

完整代码如下：