Added support for sk6812RGBW leds (ab)using the SPI interface. (#61)

right now it only uses RGB - white is set to zero

libsrc/leddevice/CMakeLists.txt

@@ -79,6 +79,7 @@ if(ENABLE_SPIDEV)
 		${CURRENT_SOURCE_DIR}/LedDeviceP9813.h
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2801.h
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2812SPI.h
+		${CURRENT_SOURCE_DIR}/LedDeviceSk6812SPI.h
 		${CURRENT_SOURCE_DIR}/LedDeviceAPA102.h
 	)
 	SET(Leddevice_SOURCES
@@ -89,6 +90,7 @@ if(ENABLE_SPIDEV)
 		${CURRENT_SOURCE_DIR}/LedDeviceP9813.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2801.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2812SPI.cpp
+		${CURRENT_SOURCE_DIR}/LedDeviceSk6812SPI.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceAPA102.cpp
 	)
 endif()

libsrc/leddevice/LedDeviceFactory.cpp

@@ -17,6 +17,7 @@
 	#include "LedDeviceP9813.h"
 	#include "LedDeviceWs2801.h"
 	#include "LedDeviceWs2812SPI.h"
+	#include "LedDeviceSk6812SPI.h"
 	#include "LedDeviceAPA102.h"
 #endif
 
@@ -147,6 +148,16 @@ LedDevice * LedDeviceFactory::construct(const Json::Value & deviceConfig)
 
 		device = deviceWs2812SPI;
 	}
+	else if (type == "sk6812spi")
+	{
+		const std::string output = deviceConfig["output"].asString();
+		const unsigned rate      = deviceConfig.get("rate",2857143).asInt();
+
+		LedDeviceSk6812SPI* deviceSk6812SPI = new LedDeviceSk6812SPI(output, rate);
+		deviceSk6812SPI->open();
+
+		device = deviceSk6812SPI;
+	}
 #endif
 #ifdef ENABLE_TINKERFORGE
 	else if (type=="tinkerforge")

libsrc/leddevice/LedDeviceSk6812SPI.cpp

@@ -0,0 +1,67 @@
+
+// STL includes
+#include <cstring>
+#include <cstdio>
+#include <iostream>
+
+// Linux includes
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+// hyperion local includes
+#include "LedDeviceSk6812SPI.h"
+
+LedDeviceSk6812SPI::LedDeviceSk6812SPI(const std::string& outputDevice, const unsigned baudrate) :
+	LedSpiDevice(outputDevice, baudrate, 0),
+	mLedCount(0),
+	bitpair_to_byte {
+		0b10001000,
+		0b10001100,
+		0b11001000,
+		0b11001100,
+	}
+
+{
+	// empty
+}
+
+int LedDeviceSk6812SPI::write(const std::vector<ColorRgb> &ledValues)
+{
+	mLedCount = ledValues.size();
+
+// 4 colours, 4 spi bytes per colour + 3 frame end latch bytes
+#define COLOURS_PER_LED		3
+#define SPI_BYTES_PER_COLOUR	4
+#define SPI_BYTES_PER_LED 	COLOURS_PER_LED * SPI_BYTES_PER_COLOUR
+
+	unsigned spi_size = mLedCount * SPI_BYTES_PER_LED + 3;
+	if(_spiBuffer.size() != spi_size){
+                _spiBuffer.resize(spi_size, 0x00);
+	}
+
+	unsigned spi_ptr = 0;
+        for (unsigned i=0; i< mLedCount; ++i) {
+		uint8_t white = 0;
+		uint32_t colorBits = 
+			((unsigned int)ledValues[i].red << 24) |
+			((unsigned int)ledValues[i].green << 16) |
+			((unsigned int)ledValues[i].blue << 8) |
+			white;
+
+		for (int j=SPI_BYTES_PER_LED - 1; j>=0; j--) {
+			_spiBuffer[spi_ptr+j] = bitpair_to_byte[ colorBits & 0x3 ];
+			colorBits >>= 2;
+		}
+		spi_ptr += SPI_BYTES_PER_LED;
+        }
+	_spiBuffer[spi_ptr++] = 0;
+	_spiBuffer[spi_ptr++] = 0;
+	_spiBuffer[spi_ptr++] = 0;
+
+	return writeBytes(spi_size, _spiBuffer.data());
+}
+
+int LedDeviceSk6812SPI::switchOff()
+{
+	return write(std::vector<ColorRgb>(mLedCount, ColorRgb{0,0,0}));
+}

libsrc/leddevice/LedDeviceSk6812SPI.h

@@ -0,0 +1,43 @@
+#pragma once
+
+// STL includes
+#include <string>
+
+// hyperion incluse
+#include "LedSpiDevice.h"
+
+///
+/// Implementation of the LedDevice interface for writing to Sk6801 led device.
+///
+class LedDeviceSk6812SPI : public LedSpiDevice
+{
+public:
+	///
+	/// Constructs the LedDevice for a string containing leds of the type Sk6812SPI
+	///
+	/// @param outputDevice The name of the output device (eg '/etc/SpiDev.0.0')
+	/// @param baudrate The used baudrate for writing to the output device
+	///
+
+	LedDeviceSk6812SPI(const std::string& outputDevice,
+					const unsigned baudrate);
+
+	///
+	/// Writes the led color values to the led-device
+	///
+	/// @param ledValues The color-value per led
+	/// @return Zero on succes else negative
+	///
+	virtual int write(const std::vector<ColorRgb> &ledValues);
+
+	/// Switch the leds off
+	virtual int switchOff();
+
+private:
+
+	/// the number of leds (needed when switching off)
+	size_t mLedCount;
+	std::vector<uint8_t> _spiBuffer;
+
+        uint8_t bitpair_to_byte[4];
+};

libsrc/leddevice/LedDeviceWs2812SPI.h

@@ -21,10 +21,6 @@ public:
 	LedDeviceWs2812SPI(const std::string& outputDevice,
 					const unsigned baudrate);
 
-	LedDeviceWs2812SPI(const std::string& outputDevice,
-					const unsigned baudrate,
-					const unsigned latchTime);
-
 	///
 	/// Writes the led color values to the led-device
 	///