hyperion.ng/libsrc/leddevice/LedDeviceAdalightApa102.cpp

// STL includes
#include <cstring>
#include <cstdio>
#include <iostream>
#include <algorithm>

// Linux includes
#include <fcntl.h>
#include <sys/ioctl.h>

// hyperion local includes
#include "LedDeviceAdalightApa102.h"

LedDeviceAdalightApa102::LedDeviceAdalightApa102(const std::string& outputDevice, const unsigned baudrate, int delayAfterConnect_ms) :
	LedDeviceAdalight(outputDevice, baudrate, delayAfterConnect_ms),
	_ledBuffer(0),
	_timer()
{
}
//comparing to ws2801 adalight, the following changes were needed:
// 1- differnt data frame (4 bytes instead of 3)
// 2 - in order to accomodate point 1 above, number of leds sent to adalight is increased by 1/3rd
int LedDeviceAdalightApa102::write(const std::vector<ColorRgb> & ledValues)
{
	const unsigned int startFrameSize = 4;
	const unsigned int endFrameSize = std::max<unsigned int>(((ledValues.size() + 15) / 16), 4);
	const unsigned int mLedCount = (ledValues.size() * 4) + startFrameSize + endFrameSize;
	if(_ledBuffer.size() != mLedCount){
		_ledBuffer.resize(mLedCount, 0xFF);
		_ledBuffer[0] = 'A';
		_ledBuffer[1] = 'd';
		_ledBuffer[2] = 'a';
		_ledBuffer[3] = (((unsigned int)(ledValues.size() * 1.33) - 1) >> 8) & 0xFF; // LED count high byte
		_ledBuffer[4] = ((unsigned int)(ledValues.size() * 1.33) - 1) & 0xFF;        // LED count low byte
		_ledBuffer[5] = _ledBuffer[3] ^ _ledBuffer[4] ^ 0x55; // Checksum
	}
	
	for (unsigned iLed=1; iLed<=ledValues.size(); iLed++) {
		const ColorRgb& rgb = ledValues[iLed-1];
		_ledBuffer[iLed*4+6]   = 0xFF;
		_ledBuffer[iLed*4+1+6] = rgb.red;
		_ledBuffer[iLed*4+2+6] = rgb.green;
		_ledBuffer[iLed*4+3+6] = rgb.blue;
	}
	
	// restart the timer
	_timer.start();

	// write data
	return writeBytes(_ledBuffer.size(), _ledBuffer.data());
}