From 299ab090f2144248574ba6845c4dee30cdc670a5 Mon Sep 17 00:00:00 2001 From: zouhaitao Date: Wed, 8 Jul 2026 14:35:46 +0800 Subject: [PATCH] feat: restore unrolled 3-bit SPI driver with push-pull clock output to resolve byte gap and write collision issues --- App/main.c | 59 +++++++++++++++++++++++------------------------------- 1 file changed, 25 insertions(+), 34 deletions(-) diff --git a/App/main.c b/App/main.c index d09ef47..cf9470d 100644 --- a/App/main.c +++ b/App/main.c @@ -128,25 +128,27 @@ void UI_ShowSosPage(void); * WS2812B 幻彩 LED 单线驱动函数 (24MHz 1T 模式下精准时序控制) * ========================================================================= */ -void WS2812_EncodeByte4(u8 v, u8 *buf) +const u16 code SPI_LUT[16] = { + 0x924, 0x926, 0x934, 0x936, 0x9A4, 0x9A6, 0x9B4, 0x9B6, + 0xD24, 0xD26, 0xD34, 0xD36, 0xDA4, 0xDA6, 0xDB4, 0xDB6 +}; + +void WS2812_EncodeByte(u8 v, u8 *buf) { - // Encode 8 FCOB bits into 4 SPI bytes (2 FCOB bits per byte) - // 0-code -> 1000 (binary), 1-code -> 1100 (binary) - buf[0] = ((v & 0x80) ? 0xC0 : 0x80) | ((v & 0x40) ? 0x0C : 0x08); - buf[1] = ((v & 0x20) ? 0xC0 : 0x80) | ((v & 0x10) ? 0x0C : 0x08); - buf[2] = ((v & 0x08) ? 0xC0 : 0x80) | ((v & 0x04) ? 0x0C : 0x08); - buf[3] = ((v & 0x02) ? 0xC0 : 0x80) | ((v & 0x01) ? 0x0C : 0x08); + u16 p1 = SPI_LUT[v >> 4]; + u16 p2 = SPI_LUT[v & 0x0F]; + buf[0] = p1 >> 4; + buf[1] = ((p1 & 0x0F) << 4) | (p2 >> 8); + buf[2] = p2; } void WS2812_Write24Bit(u8 g, u8 r, u8 b) { - u8 xdata buf[12]; - u8 i; - u16 timeout; + u8 xdata buf[9]; - WS2812_EncodeByte4(g, &buf[0]); - WS2812_EncodeByte4(r, &buf[4]); - WS2812_EncodeByte4(b, &buf[8]); + WS2812_EncodeByte(g, &buf[0]); + WS2812_EncodeByte(r, &buf[3]); + WS2812_EncodeByte(b, &buf[6]); EA = 0; @@ -155,28 +157,17 @@ void WS2812_Write24Bit(u8 g, u8 r, u8 b) P2M0 |= ((1 << 3) | (1 << 5)); SPCTL = 0xD0; // Enable SPI at SYSCLK/4 (3.0 MHz actual clock on board) - SPSTAT = 0xC0; // Clear flags - SPDAT = buf[0]; // Start transmitting buf[0] - // Wait 16 system cycles to ensure buf[0] has moved to shifter - _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); - _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); - SPDAT = buf[1]; // Buffer buf[1] - - for (i = 2; i < 12; i++) - { - timeout = 2000; - while (!(SPSTAT & 0x80) && --timeout); // Wait for buf[i-2] to finish, buf[i-1] moves to shifter - SPSTAT = 0xC0; - SPDAT = buf[i]; // Buffer buf[i] (zero gap!) - } - - timeout = 2000; - while (!(SPSTAT & 0x80) && --timeout); // Wait for buf[10] to finish, buf[11] moves to shifter - SPSTAT = 0xC0; - - timeout = 2000; - while (!(SPSTAT & 0x80) && --timeout); // Wait for buf[11] to finish + // Unrolled 9-byte transmission with minimal gap (~300ns) + SPSTAT = 0xC0; SPDAT = buf[0]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[1]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[2]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[3]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[4]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[5]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[6]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[7]; while (!(SPSTAT & 0x80)); + SPSTAT = 0xC0; SPDAT = buf[8]; while (!(SPSTAT & 0x80)); SPSTAT = 0xC0; SPCTL = 0x90; // Disable SPI