hyperion.ng/libsrc/leddevice/LedDeviceWs2812b.cpp
T. van der Zwan 71b8fd4879 Modification and additions to test working of ws2812b
Former-commit-id: 2a7eb3cb67c85a4a4042bd0f1a6ea4d58792b1c2
2013-12-28 07:34:49 +00:00

115 lines
2.7 KiB
C++

// Linux includes
#include <unistd.h>
// Local Hyperion-Leddevice includes
#include "LedDeviceWs2812b.h"
LedDeviceWs2812b::LedDeviceWs2812b() :
LedRs232Device("/dev/ttyAMA0", 4000000)
{
fillTable();
}
int LedDeviceWs2812b::write(const std::vector<ColorRgb> & ledValues)
{
// Ensure the size of the led-buffer
if (_ledBuffer.size() != ledValues.size()*3)
{
_ledBuffer.resize(ledValues.size()*3);
}
// Translate the channel of each color to a signal
for (unsigned iLed=0; iLed<ledValues.size(); ++iLed)
{
const ColorRgb & color = ledValues[iLed];
_ledBuffer[3*iLed] = _byte2signalTable[color.red];
_ledBuffer[3*iLed + 1] = _byte2signalTable[color.green];
_ledBuffer[3*iLed + 2] = _byte2signalTable[color.blue];
}
const int result = writeBytes(_ledBuffer.size()*sizeof(ByteSignal), reinterpret_cast<uint8_t *>(_ledBuffer.data()));
// Official latch time is 50us (lets give it 50us more)
usleep(100);
return result;
}
int LedDeviceWs2812b::switchOff()
{
// Set all bytes in the signal buffer to zero
for (ByteSignal & signal : _ledBuffer)
{
signal = _byte2signalTable[0];
}
return writeBytes(_ledBuffer.size()*sizeof(ByteSignal), reinterpret_cast<uint8_t *>(_ledBuffer.data()));
}
void LedDeviceWs2812b::fillTable()
{
_byte2signalTable.clear();
for (int byte=0; byte<256; ++byte)
{
const ByteSignal signal = byte2Signal(uint8_t(byte));
_byte2signalTable.push_back(signal);
}
}
LedDeviceWs2812b::ByteSignal LedDeviceWs2812b::byte2Signal(const uint8_t byte) const
{
ByteSignal result;
result.bit_12 = bits2Signal(byte & 0x80, byte & 0x40);
result.bit_34 = bits2Signal(byte & 0x20, byte & 0x10);
result.bit_56 = bits2Signal(byte & 0x08, byte & 0x04);
result.bit_78 = bits2Signal(byte & 0x02, byte & 0x01);
return result;
}
uint8_t LedDeviceWs2812b::bits2Signal(const bool bit1, const bool bit2) const
{
// See https://github.com/tvdzwan/hyperion/wiki/Ws2812b for the explanation of the given
// translations
// Encoding scheme 1
// 00 1 1000 1100 0 1 0111 0011 0 1 1100 1110 0 0xCE
// 01 1 1000 1110 0 1 0111 0001 0 1 1000 1110 0 0x8E
// 10 1 1100 1100 0 1 0011 0011 0 1 1100 1100 0 0xCC
// 11 1 1100 1110 0 1 0011 0001 0 1 1000 1100 0 0x8C
// Encoding schem 2
// 00 - 1 0000 1000 0 - 1 1111 0111 0 - 1 1110 1111 0 - 0xEF
// 01 - 1 0000 1111 0 - 1 1111 0000 0 - 1 0000 1111 0 - 0x0F
// 10 - 1 1110 1000 0 - 1 0001 0111 0 - 1 1110 1000 0 - 0xE8
// 11 - 1 1110 1111 0 - 1 0001 0000 0 - 1 0000 1000 0 - 0x08
if (bit1)
{
if (bit2)
{
// return 0x08;
return 0x8C;
}
else
{
// return 0xE8;
return 0xCC;
}
}
else
{
if (bit2)
{
// return 0x0F;
return 0x8E;
}
else
{
// return 0xEF;
return 0xCE;
}
}
return 0x00;
}