Add support for the WS2801 protocol (#55)

WS2801 uses a SPI-like two-wire protocol with clock and data.

Although some datasheets mention maximum clock speeds of 2MHz or even
25MHz most LED strips only work reliably up to 1MHz so use that to stay
on the safe side.

The data frame is 24 bit R, G, B (in this order) per LED, a pause of
500us resets the LED index.

Signed-off-by: Matthias Reichl <[email protected]>

Author: HiassofT

CMakeLists.txt

@@ -129,6 +129,8 @@ IF(NOT SECOND_SEGMENT_INDEX)
     IF(NOT DISABLE_SPI_LEDS)
         HyperSerialPicoTarget("${CMAKE_PROJECT_NAME}_Spi")
         target_compile_definitions("${CMAKE_PROJECT_NAME}_Spi" PRIVATE -DSPILED_APA102 -DSPI_INTERFACE=${OUTPUT_SPI_INTERFACE} -DDATA_PIN=${OUTPUT_SPI_DATA_PIN} -DCLOCK_PIN=${OUTPUT_SPI_CLOCK_PIN})
+        HyperSerialPicoTarget("${CMAKE_PROJECT_NAME}_ws2801")
+        target_compile_definitions("${CMAKE_PROJECT_NAME}_ws2801" PRIVATE -DSPILED_WS2801 -DSPI_INTERFACE=${OUTPUT_SPI_INTERFACE} -DDATA_PIN=${OUTPUT_SPI_DATA_PIN} -DCLOCK_PIN=${OUTPUT_SPI_CLOCK_PIN})
     endif()
     HyperSerialPicoTarget("${CMAKE_PROJECT_NAME}_sk6812Cold")
     target_compile_definitions("${CMAKE_PROJECT_NAME}_sk6812Cold" PRIVATE -DNEOPIXEL_RGBW -DCOLD_WHITE -DDATA_PIN=${OUTPUT_DATA_PIN})

include/calibration.h

@@ -35,6 +35,8 @@
 	#endif
 #elif SPILED_APA102
 	typedef ColorDotstartBgr ColorDefinition;
+#elif SPILED_WS2801
+	typedef ColorRgb ColorDefinition;
 #endif
 
 

include/leds.h

@@ -155,6 +155,22 @@ struct ColorDotstartBgr
 	};
 };
 
+struct ColorRgb
+{
+	uint8_t R;
+	uint8_t G;
+	uint8_t B;
+
+	ColorRgb(uint8_t gray) :
+		R(gray), G(gray), B(gray)
+	{
+	};
+
+	ColorRgb() : R(0), G(0), B(0)
+	{
+	};
+};
+
 class LedDriver
 {
 	protected:
@@ -559,6 +575,73 @@ class DotstarType : public Dotstar
 	}
 };
 
+class Ws2801 : public LedDriver, public DmaClient
+{
+	uint64_t resetTime;
+
+	public:
+	Ws2801(uint64_t _resetTime, int _ledsNumber, spi_inst_t* _spi, uint32_t _datapin, uint32_t _clockpin, int _dmaSize):
+			LedDriver(_ledsNumber, _datapin, _clockpin, _dmaSize)
+	{
+		dmaConfigure(pio0, 0);
+		resetTime = _resetTime;
+
+		spi_init(_spi, 1000000);
+		gpio_set_function(_clockpin, GPIO_FUNC_SPI);
+		gpio_set_function(_datapin, GPIO_FUNC_SPI);
+		bi_decl(bi_4pins_with_func(PICO_DEFAULT_SPI_RX_PIN, _datapin, _clockpin, PICO_DEFAULT_SPI_CSN_PIN, GPIO_FUNC_SPI));
+
+		initDmaSpi(_spi, _dmaSize);
+	}
+
+	uint8_t* getBufferMemory()
+	{
+		return buffer;
+	}
+
+	protected:
+
+	void renderDma()
+	{
+		if (isDmaBusy)
+			return;
+
+		isDmaBusy = true;
+
+		uint64_t currentTime = time_us_64();
+		if (currentTime < resetTime + lastRenderTime)
+			busy_wait_us(std::min(resetTime + lastRenderTime - currentTime, resetTime));
+
+		memcpy(dma, buffer, dmaSize);
+
+		dma_channel_set_read_addr(PICO_DMA_CHANNEL, dma, true);
+	}
+};
+
+template<int RESET_TIME, typename colorData>
+class Ws2801Type : public Ws2801
+{
+	public:
+
+	Ws2801Type(int _ledsNumber, spi_inst_t* _spi, int _dataPin, int _clockPin) :
+		Ws2801(RESET_TIME, _ledsNumber, _spi, _dataPin, _clockPin, _ledsNumber * sizeof(colorData))
+	{
+	}
+
+	void SetPixel(int index, colorData color)
+	{
+		if (index >= ledsNumber)
+			return;
+
+		*(reinterpret_cast<colorData*>(buffer)+index) = color;
+	}
+
+	void renderSingleLane()
+	{
+		renderDma();
+	}
+};
+
 Neopixel* NeopixelParallel::muxer = nullptr;
 uint8_t* NeopixelParallel::buffer = nullptr;
 int NeopixelParallel::instances = 0;
@@ -574,3 +657,4 @@ typedef NeopixelType<NeopixelSubtype::sk6812, 450, ColorGrbw> sk6812;
 typedef NeopixelParallelType<NeopixelSubtype::ws2812b, 300, ColorGrb> ws2812p;
 typedef NeopixelParallelType<NeopixelSubtype::sk6812, 80, ColorGrbw> sk6812p;
 typedef DotstarType<100, ColorDotstartBgr> apa102;
+typedef Ws2801Type<500, ColorRgb> ws2801;

source/main.cpp

@@ -69,6 +69,9 @@
 #ifdef SPILED_APA102
 	#pragma message(VAR_NAME_VALUE(SPILED_APA102))
 #endif
+#ifdef SPILED_WS2801
+	#pragma message(VAR_NAME_VALUE(SPILED_WS2801))
+#endif
 
 #ifdef NEOPIXEL_RGBW
 	#define LED_DRIVER sk6812
@@ -80,6 +83,10 @@
 	#define LED_DRIVER apa102
 	#pragma message(VAR_NAME_VALUE(SPI_INTERFACE))
 #endif
+#ifdef SPILED_WS2801
+	#define LED_DRIVER ws2801
+	#pragma message(VAR_NAME_VALUE(SPI_INTERFACE))
+#endif
 
 	#pragma message(VAR_NAME_VALUE(DATA_PIN))
 #ifdef CLOCK_PIN