hyperion.ng/libsrc/leddevice/dev_spi/LedDeviceSK9822.cpp

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#include "LedDeviceSK9822.h"
// Local Hyperion includes
#include <utils/Logger.h>
/// The value that determines the higher bits of the SK9822 global brightness control field
const int SK9822_GBC_UPPER_BITS = 0xE0;
/// The maximal current level supported by the SK9822 global brightness control field, 31
const int SK9822_GBC_MAX_LEVEL = 0x1F;
LedDeviceSK9822::LedDeviceSK9822(const QJsonObject &deviceConfig)
: ProviderSpi(deviceConfig)
, _globalBrightnessControlThreshold(255)
, _globalBrightnessControlMaxLevel(SK9822_GBC_MAX_LEVEL)
{
}
LedDevice *LedDeviceSK9822::construct(const QJsonObject &deviceConfig)
{
return new LedDeviceSK9822(deviceConfig);
}
bool LedDeviceSK9822::init(const QJsonObject &deviceConfig)
{
bool isInitOK = false;
// Initialise sub-class
if (ProviderSpi::init(deviceConfig))
{
_globalBrightnessControlThreshold = deviceConfig["globalBrightnessControlThreshold"].toInt(255);
_globalBrightnessControlMaxLevel = deviceConfig["globalBrightnessControlMaxLevel"].toInt(SK9822_GBC_MAX_LEVEL);
Info(_log, "[SK9822] Using global brightness control with threshold of %d and max level of %d", _globalBrightnessControlThreshold, _globalBrightnessControlMaxLevel);
const unsigned int startFrameSize = 4;
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const unsigned int endFrameSize = ((_ledCount/32) + 1)*4;
const unsigned int bufferSize = (_ledCount * 4) + startFrameSize + endFrameSize;
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_ledBuffer.resize(0, 0x00);
_ledBuffer.resize(bufferSize, 0x00);
isInitOK = true;
}
return isInitOK;
}
void LedDeviceSK9822::bufferWithMaxCurrent(std::vector<uint8_t> &txBuf, const std::vector<ColorRgb> & ledValues, const int maxLevel) {
const int ledCount = static_cast<int>(_ledCount);
for (int iLed = 0; iLed < ledCount; ++iLed)
{
const ColorRgb &rgb = ledValues[iLed];
const uint8_t red = rgb.red;
const uint8_t green = rgb.green;
const uint8_t blue = rgb.blue;
/// The LED index in the buffer
const int b = 4 + iLed * 4;
// Use 0/31 LED-Current for Black, and full LED-Current for all other colors,
// with PWM control on RGB-Channels
const int ored = (red|green|blue);
txBuf[b + 0] = ((ored > 0) * (maxLevel & SK9822_GBC_MAX_LEVEL)) | SK9822_GBC_UPPER_BITS; // (ored > 0) is 1 for any r,g,b > 0, 0 otherwise; branch free
txBuf[b + 1] = red;
txBuf[b + 2] = green;
txBuf[b + 3] = blue;
}
}
inline __attribute__((always_inline)) unsigned LedDeviceSK9822::scale(const uint8_t value, const int maxLevel, const uint16_t brightness) {
return (((maxLevel * value + (brightness >> 1)) / brightness));
}
void LedDeviceSK9822::bufferWithAdjustedCurrent(std::vector<uint8_t> &txBuf, const std::vector<ColorRgb> & ledValues, const int threshold, const int maxLevel) {
const int ledCount = static_cast<int>(_ledCount);
for (int iLed = 0; iLed < ledCount; ++iLed)
{
const ColorRgb &rgb = ledValues[iLed];
uint8_t red = rgb.red;
uint8_t green = rgb.green;
uint8_t blue = rgb.blue;
uint8_t level;
/// The LED index in the buffer
const int b = 4 + iLed * 4;
/// The maximal r,g,b-channel grayscale value of the LED
const uint16_t /* expand to 16 bit! */ maxValue = std::max(std::max(red, green), blue);
if (maxValue == 0) {
// Use 0/31 LED-Current for Black
level = 0;
red = 0x00;
green = 0x00;
blue = 0x00;
} else if (maxValue >= threshold) {
// Use full LED-Current when maximal r,g,b-channel grayscale value >= threshold and just use PWM control
level = (maxLevel & SK9822_GBC_MAX_LEVEL);
} else {
// Use adjusted LED-Current for other r,g,b-channel grayscale values
// See also: https://github.com/FastLED/FastLED/issues/656
// Scale the r,g,b-channel grayscale values to adjusted current = brightness level
const uint16_t /* 16 bit! */ brightness = (((maxValue + 1) * maxLevel - 1) >> 8) + 1;
level = (brightness & SK9822_GBC_MAX_LEVEL);
red = scale(red, maxLevel, brightness);
green = scale(green, maxLevel, brightness);
blue = scale(blue, maxLevel, brightness);
}
txBuf[b + 0] = level | SK9822_GBC_UPPER_BITS;
txBuf[b + 1] = red;
txBuf[b + 2] = green;
txBuf[b + 3] = blue;
}
}
int LedDeviceSK9822::write(const std::vector<ColorRgb> &ledValues)
{
const int threshold = _globalBrightnessControlThreshold;
const int maxLevel = _globalBrightnessControlMaxLevel;
if(threshold > 0) {
this->bufferWithAdjustedCurrent(_ledBuffer, ledValues, threshold, maxLevel);
} else {
this->bufferWithMaxCurrent(_ledBuffer, ledValues, maxLevel);
}
return writeBytes(_ledBuffer.size(), _ledBuffer.data());
}