[untested] added Sk6822 led device support (#397)

* Adding support for sk6822 timing
This isnt complete, but should be a good starting point for others to learn from.

1) Here is where the led device source is located:

cd libsrc/leddevice

2) Find the files that need changing:

root@loungepi:libsrc/leddevice# grep -ri 2812spi *
CMakeLists.txt:         ${CURRENT_SOURCE_DIR}/LedDeviceWs2812SPI.h
CMakeLists.txt:         ${CURRENT_SOURCE_DIR}/LedDeviceWs2812SPI.cpp
LedDeviceFactory.cpp:   #include "LedDeviceWs2812SPI.h"
LedDeviceFactory.cpp:   REGISTER(Ws2812SPI);
LedDeviceSchemas.qrc:           <file alias="schema-ws2812spi">schemas/schema-ws2812spi.json</file>
LedDeviceWs2812SPI.cpp:#include "LedDeviceWs2812SPI.h"
LedDeviceWs2812SPI.cpp:LedDeviceWs2812SPI::LedDeviceWs2812SPI(const QJsonObject &deviceConfig)
LedDeviceWs2812SPI.cpp:LedDevice* LedDeviceWs2812SPI::construct(const QJsonObject &deviceConfig)
LedDeviceWs2812SPI.cpp: return new LedDeviceWs2812SPI(deviceConfig);
LedDeviceWs2812SPI.cpp:bool LedDeviceWs2812SPI::init(const QJsonObject &deviceConfig)
LedDeviceWs2812SPI.cpp:int LedDeviceWs2812SPI::write(const std::vector<ColorRgb> &ledValues)
LedDeviceWs2812SPI.h:class LedDeviceWs2812SPI : public ProviderSpi
LedDeviceWs2812SPI.h:   LedDeviceWs2812SPI(const QJsonObject &deviceConfig);

3) Copy the existing files as a starting point:

cp LedDeviceWs2812SPI.cpp LedDeviceSk6822SPI.cpp
cp LedDeviceWs2812SPI.h LedDeviceSk6822SPI.h
cp schemas/schema-ws2812spi.json schemas/schema-sk6822spi.json

4) Do some search and replacing:

:%s/Ws2812SPI/Sk6822SPI/g

5) edit the other files (see the diffs in this commit)

* Added wait time and reset time

* Fixed up debugging output and commented it out.

assets/webconfig/js/content_leds.js

@@ -464,7 +464,7 @@ $(document).ready(function() {
 	
 	// create led device selection
 	ledDevices = serverInfo.info.ledDevices.available
-	devRPiSPI = ['apa102', 'ws2801', 'lpd6803', 'lpd8806', 'p9813', 'sk6812spi', 'ws2812spi'];
+	devRPiSPI = ['apa102', 'ws2801', 'lpd6803', 'lpd8806', 'p9813', 'sk6812spi', 'sk6822spi', 'ws2812spi'];
 	devRPiPWM = ['ws281x'];
 	devRPiGPIO = ['piblaster'];
 	devNET = ['atmoorb', 'fadecandy', 'philipshue', 'tinkerforge', 'tpm2net', 'udpe131', 'udph801', 'udpraw'];

libsrc/leddevice/CMakeLists.txt

@@ -82,6 +82,7 @@ if(ENABLE_SPIDEV)
 		${CURRENT_SOURCE_DIR}/LedDeviceP9813.h
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2801.h
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2812SPI.h
+		${CURRENT_SOURCE_DIR}/LedDeviceSk6822SPI.h
 		${CURRENT_SOURCE_DIR}/LedDeviceSk6812SPI.h
 		${CURRENT_SOURCE_DIR}/LedDeviceAPA102.h
 	)
@@ -93,6 +94,7 @@ if(ENABLE_SPIDEV)
 		${CURRENT_SOURCE_DIR}/LedDeviceP9813.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2801.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceWs2812SPI.cpp
+		${CURRENT_SOURCE_DIR}/LedDeviceSk6822SPI.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceSk6812SPI.cpp
 		${CURRENT_SOURCE_DIR}/LedDeviceAPA102.cpp
 	)

libsrc/leddevice/LedDeviceFactory.cpp

@@ -21,6 +21,7 @@
 	#include "LedDeviceWs2801.h"
 	#include "LedDeviceWs2812SPI.h"
 	#include "LedDeviceSk6812SPI.h"
+	#include "LedDeviceSk6822SPI.h"
 	#include "LedDeviceAPA102.h"
 #endif
 
@@ -82,6 +83,7 @@ LedDevice * LedDeviceFactory::construct(const QJsonObject & deviceConfig, const
 	REGISTER(Ws2801);
 	REGISTER(Ws2812SPI);
 	REGISTER(Sk6812SPI);
+	REGISTER(Sk6822SPI);
 	#endif
 	
 	// pwm devices

libsrc/leddevice/LedDeviceSchemas.qrc

@@ -19,6 +19,7 @@
 		<file alias="schema-rawhid">schemas/schema-rawhid.json</file>
 		<file alias="schema-sedu">schemas/schema-sedu.json</file>
 		<file alias="schema-sk6812spi">schemas/schema-sk6812spi.json</file>
+		<file alias="schema-sk6822spi">schemas/schema-sk6822spi.json</file>
 		<file alias="schema-tinkerforge">schemas/schema-tinkerforge.json</file>
 		<file alias="schema-tpm2net">schemas/schema-tpm2net.json</file>
 		<file alias="schema-tpm2">schemas/schema-tpm2.json</file>

libsrc/leddevice/LedDeviceSk6822SPI.cpp

@@ -0,0 +1,118 @@
+#include "LedDeviceSk6822SPI.h"
+/*
+From the data sheet:
+
+(TH+TL=1.7μs±600ns)
+
+T0H,	 0 code, high level time,	 0.35µs ±0.150ns
+T0L,	 0 code, low level time,	 1.36µs ±0.150ns
+T1H,	 1 code, high level time,	 1.36µs ±0.150ns
+T1L,	 1 code, low level time,	 0.35µs ±0.150ns
+WT,	 Wait for the processing time,	 12µs ±0.150ns
+Trst,	 Reset code,low level time,	 50µs
+
+To normalise the pulse times so they fit in 4 SPI bits:
+
+Use timings at upper end of tolerance:
+1.36 -> 1.50 uS
+0.35 -> 0.50 uS
+
+A SPI bit time of 0.50uS = 2Mbit/sec
+T0 is sent as 1000
+T1 is sent as 1110
+
+With a bit of excel testing, we can work out the maximum and minimum speeds:
+2000000 MIN
+2230000 AVG
+2460000 MAX
+
+Wait time:
+using the min of  2000000, the bit time is 0.500
+Wait time is 12uS = 24 bits = 3 bytes
+
+Reset time:
+using the min of  2000000, the bit time is 0.500
+Reset time is 50uS = 100 bits = 13 bytes
+
+*/
+
+
+LedDeviceSk6822SPI::LedDeviceSk6822SPI(const QJsonObject &deviceConfig)
+	: ProviderSpi()
+	, SPI_BYTES_PER_COLOUR(4)
+	, SPI_BYTES_WAIT_TIME(3)
+	, SPI_FRAME_END_LATCH_BYTES(13)
+	, bitpair_to_byte {
+		0b10001000,
+		0b10001110,
+		0b11101000,
+		0b11101110,
+	}
+{
+	_deviceReady = init(deviceConfig);
+}
+
+LedDevice* LedDeviceSk6822SPI::construct(const QJsonObject &deviceConfig)
+{
+	return new LedDeviceSk6822SPI(deviceConfig);
+}
+
+bool LedDeviceSk6822SPI::init(const QJsonObject &deviceConfig)
+{
+	_baudRate_Hz = 2230000;
+	if ( !ProviderSpi::init(deviceConfig) )
+	{
+		return false;
+	}
+	WarningIf(( _baudRate_Hz < 2000000 || _baudRate_Hz > 2460000 ), _log, "SPI rate %d outside recommended range (2000000 -> 2460000)", _baudRate_Hz);
+
+	_ledBuffer.resize( (_ledRGBCount *  SPI_BYTES_PER_COLOUR) + (_ledCount * SPI_BYTES_WAIT_TIME ) + SPI_FRAME_END_LATCH_BYTES, 0x00);
+//	Debug(_log, "_ledBuffer.resize(_ledRGBCount:%d * SPI_BYTES_PER_COLOUR:%d) + ( _ledCount:%d * SPI_BYTES_WAIT_TIME:%d ) + SPI_FRAME_END_LATCH_BYTES:%d, 0x00)", _ledRGBCount, SPI_BYTES_PER_COLOUR, _ledCount, SPI_BYTES_WAIT_TIME,  SPI_FRAME_END_LATCH_BYTES);
+
+	return true;
+}
+
+int LedDeviceSk6822SPI::write(const std::vector<ColorRgb> &ledValues)
+{
+	unsigned spi_ptr = 0;
+	const int SPI_BYTES_PER_LED = sizeof(ColorRgb) * SPI_BYTES_PER_COLOUR;
+
+	for (const ColorRgb& color : ledValues)
+	{
+		uint32_t colorBits = ((unsigned int)color.red << 16)
+			| ((unsigned int)color.green << 8)
+			| color.blue;
+
+		for (int j=SPI_BYTES_PER_LED - 1; j>=0; j--)
+		{
+			_ledBuffer[spi_ptr+j] = bitpair_to_byte[ colorBits & 0x3 ];
+			colorBits >>= 2;
+		}
+		spi_ptr += SPI_BYTES_PER_LED;
+		spi_ptr += SPI_BYTES_WAIT_TIME;	// the wait between led time is all zeros
+	}
+
+
+/*
+// debug the whole SPI packet
+	char debug_line[2048];
+	int ptr=0;
+	for (unsigned int i=0; i < _ledBuffer.size(); i++)
+	{
+		if (i%16 == 0)
+		{
+			ptr += snprintf (ptr+debug_line, sizeof(debug_line)-ptr, "%03x: ", i);
+		}
+
+		ptr += snprintf (ptr+debug_line, sizeof(debug_line)-ptr, "%02x ", _ledBuffer.data()[i]);
+
+		if ( (i%16 == 15) || ( i == _ledBuffer.size()-1 ) )
+		{
+			Debug(_log, debug_line);
+			ptr = 0;
+		}
+	}
+*/
+
+	return writeBytes(_ledBuffer.size(), _ledBuffer.data());
+}

libsrc/leddevice/LedDeviceSk6822SPI.h

@@ -0,0 +1,44 @@
+#pragma once
+
+// hyperion incluse
+#include "ProviderSpi.h"
+
+///
+/// Implementation of the LedDevice interface for writing to Ws2812 led device via spi.
+///
+class LedDeviceSk6822SPI : public ProviderSpi
+{
+public:
+	///
+	/// Constructs specific LedDevice
+	///
+	/// @param deviceConfig json device config
+	///
+	LedDeviceSk6822SPI(const QJsonObject &deviceConfig);
+
+	/// constructs leddevice
+	static LedDevice* construct(const QJsonObject &deviceConfig);
+
+	///
+	/// Sets configuration
+	///
+	/// @param deviceConfig the json device config
+	/// @return true if success
+	virtual bool init(const QJsonObject &deviceConfig);
+
+private:
+	///
+	/// 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);
+
+	const int SPI_BYTES_PER_COLOUR;
+	const int SPI_BYTES_WAIT_TIME;
+	const int SPI_FRAME_END_LATCH_BYTES;
+
+
+	uint8_t bitpair_to_byte[4];
+};

libsrc/leddevice/schemas/schema-sk6822spi.json

@@ -0,0 +1,25 @@
+{
+	"type":"object",
+	"required":true,
+	"properties":{
+		"output": {
+			"type": "string",
+			"title":"edt_dev_spec_spipath_title",
+			"enum" : ["/dev/spidev0.0","/dev/spidev0.1"],
+			"propertyOrder" : 1
+		},
+		"rate": {
+			"type": "integer",
+			"title":"edt_dev_spec_baudrate_title",
+			"default": 2230000,
+			"propertyOrder" : 2
+		},
+		"invert": {
+			"type": "boolean",
+			"title":"edt_dev_spec_invert_title",
+			"default": false,
+			"propertyOrder" : 3
+		}
+	},
+	"additionalProperties": true
+}