135 lines
4.4 KiB
Markdown
135 lines
4.4 KiB
Markdown
# 编码实现 - WS2812B 可编程 RGB 灯效 (Docs/60_coding/mod-led.md)
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本文件对应可编程幻彩 RGB 灯珠硬件 SPI 驱动与报警指示灯控的编码实现细节。
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## 1. 对应代码源文件
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* [App/main.c](file:///c:/workfile/105/stc32g12k128/App/main.c) (定义 SPI 配置、展宽查表及 1ms 定时中断中的闪烁控制)
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## 2. 关键代码片段与逻辑实现
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### 2.1 驱动初始化与管脚分配
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WS2812B 输入脚接在单片机硬件 SPI 组管脚中的 MOSI (`P2.3`)：
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```c
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sbit WS2812_DI = P2^3;
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void WS2812_Init(void) {
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// P2.3 (MOSI) 配置为推挽输出，默认输出低电平 0
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P2M1 &= ~(1 << 3);
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P2M0 |= (1 << 3);
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WS2812_DI = 0;
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}
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```
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### 2.2 硬件 SPI 防噪声极速发送 (WS2812_Write24Bit)
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由于 SPI 时钟 SCLK 与马达引脚复用 `P2.5`，发送期间关闭总中断并将 `P2.5` 设为高阻输入以规避马达杂音，通过 SPDAT 展开 24bit 数据串行输出。
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展宽 LUT 定义：
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```c
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const u16 code SPI_LUT[16] = {
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0x924, 0x926, 0x934, 0x936, 0x9A4, 0x9A6, 0x9B4, 0x9B6,
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0xD24, 0xD26, 0xD34, 0xD36, 0xDA4, 0xDA6, 0xDB4, 0xDB6
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};
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```
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发送函数实现：
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```c
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void WS2812_Write24Bit(u8 g, u8 r, u8 b) {
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u8 data buf[10];
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u8 b0, b1, b2, b3, b4, b5, b6, b7, b8, b9;
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buf[0] = 0x00; // 虚拟前导字节，吸收硬件启动瞬态抖动
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WS2812_EncodeByte(g, &buf[1]);
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WS2812_EncodeByte(r, &buf[4]);
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WS2812_EncodeByte(b, &buf[7]);
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b0 = buf[0]; b1 = buf[1]; b2 = buf[2]; b3 = buf[3];
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b4 = buf[4]; b5 = buf[5]; b6 = buf[6]; b7 = buf[7];
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b8 = buf[8]; b9 = buf[9];
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EA = 0; // 关中断保证 SPI 传输的连续性
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// 配置 P2.5 为高阻输入模式，屏蔽马达噪声
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P2M1 |= (1 << 5);
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P2M0 &= ~(1 << 5);
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SPSTAT = 0xC0; // 清除 SPI 状态寄存器
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SPDAT = b0; // 发送数据
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SPCTL = 0xD0; // 开启 SPI 硬件传输
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// 展开的非阻塞高速发送时序 - 发送第 1 个灯珠 (Top LED)
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b1;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b2;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b3;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b4;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b5;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b6;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b7;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b8;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b9;
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// 展开的非阻塞高速发送时序 - 发送第 2 个灯珠 (Bottom LED, 级联相同颜色)
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b1;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b2;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b3;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b4;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b5;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b6;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b7;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b8;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPDAT = b9;
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while (!(SPSTAT & 0x80)); SPSTAT = 0xC0;
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SPCTL = 0x90; // 关闭 SPI 硬件使能
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WS2812_DI = 0;
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// 恢复 P2.5 为推挽输出，控制马达常规功能
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P2M1 &= ~(1 << 5);
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P2M0 |= (1 << 5);
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MOTOR = 0; // 确保马达断开
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EA = 1; // 恢复中断
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}
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void WS2812_Reset(void) {
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WS2812_DI = 0;
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// 延时 > 80us 触发重置
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{
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u8 i;
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for (i = 0; i < 100; i++) {
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_nop_();
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}
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}
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}
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```
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### 2.3 报警状态交替闪烁逻辑 (LED_Flash_Process)
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在 `Timer1_Isr` (每 10ms 调用一次) 中，管理指示灯闪烁状态：
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```c
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u16 led_flash_time = 0;
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bit led_flash_state = 0;
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bit led_running_flag = 0;
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u8 led_color_r = 0, led_color_g = 0, led_color_b = 0;
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void LED_Flash_Process(void) {
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if (!led_running_flag) {
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WS2812_Write24Bit(0, 0, 0); // 关闭 LED
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WS2812_Reset();
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return;
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}
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led_flash_time += 10;
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if (led_flash_time >= 500) { // 500ms 交替周期
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led_flash_time = 0;
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led_flash_state = ~led_flash_state;
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if (led_flash_state) {
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WS2812_Write24Bit(led_color_g, led_color_r, led_color_b);
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} else {
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WS2812_Write24Bit(0, 0, 0);
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}
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WS2812_Reset();
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}
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}
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```
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<!-- Checked and verified with SGM3833 boost/inverting PMIC removal and LCD_PWR_CTRL update changes -->
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