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Improve PWM on ESP8266

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- Better phase updates without dropping samples
- Make second pin duty cycle always after first, even inverted
This commit is contained in:
Will Miles
2024-09-29 10:00:27 -04:00
parent 3c7f83407b
commit 59deebc961
2 changed files with 19 additions and 12 deletions
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18
lib/ESP8266PWM/src/core_esp8266_waveform_phase.cpp
View File

@@ -242,7 +242,7 @@ int startWaveformClockCycles_weak(uint8_t pin, uint32_t highCcys, uint32_t lowCc
wave.mode = WaveformMode::UPDATEEXPIRY;
std::atomic_thread_fence(std::memory_order_release);
waveform.toSetBits = 1UL << pin;
} else if (alignPhase) {
} else if (alignPhase >= 0) {
// @willmmiles new feature
wave.mode = WaveformMode::UPDATEPHASE; // recalculate start
std::atomic_thread_fence(std::memory_order_release);
@@ -303,7 +303,7 @@ static inline IRAM_ATTR int32_t scaleCcys(const int32_t ccys, const bool isCPU2X
static IRAM_ATTR void timer1Interrupt() {
const uint32_t isrStartCcy = ESP.getCycleCount();
int32_t clockDrift = isrStartCcy - waveform.nextEventCcy;
//int32_t clockDrift = isrStartCcy - waveform.nextEventCcy;
// ----- @willmmiles begin patch -----
nmiCrashWorkaround();
@@ -341,12 +341,16 @@ static IRAM_ATTR void timer1Interrupt() {
break;
// @willmmiles new feature
case WaveformMode::UPDATEPHASE:
// in WaveformMode::UPDATEPHASE, we recalculate the targets without adjusting the state
// in WaveformMode::UPDATEPHASE, we recalculate the targets
if (waveform.alignPhase >= 0 && waveform.enabled & (1UL << waveform.alignPhase)) {
// Compute phase shift to realign with target
auto& align_wave = waveform.pins[waveform.alignPhase];
// Go back one cycle
wave.nextPeriodCcy = align_wave.nextPeriodCcy - scaleCcys(align_wave.periodCcys, isCPU2X) + scaleCcys(waveform.phaseCcy, isCPU2X);
wave.endDutyCcy = wave.nextPeriodCcy + scaleCcys(wave.dutyCcys, isCPU2X);
int32_t shift = static_cast<int32_t>(align_wave.nextPeriodCcy + scaleCcys(waveform.phaseCcy, isCPU2X) - wave.nextPeriodCcy);
const int32_t periodCcys = scaleCcys(wave.periodCcys, isCPU2X);
if (shift > periodCcys/2) shift -= periodCcys;
else if (shift <= -periodCcys/2) shift += periodCcys;
wave.nextPeriodCcy += shift;
wave.endDutyCcy += shift;
}
default:
break;
@@ -462,7 +466,7 @@ static IRAM_ATTR void timer1Interrupt() {
}
now = ESP.getCycleCount();
}
clockDrift = 0;
//clockDrift = 0;
}
int32_t callbackCcys = 0;

11
wled00/bus_manager.cpp
View File

@@ -565,7 +565,7 @@ void BusPwm::show() {
const unsigned analogPeriod = F_CPU / _frequency;
const unsigned maxBri = analogPeriod; // compute to clock cycle accuracy
constexpr bool dithering = false;
constexpr unsigned bitShift = 7; // 2^7 clocks for dead time
constexpr unsigned bitShift = 8; // 256 clocks for dead time, ~3us at 80MHz
#else
// if _needsRefresh is true (UI hack) we are using dithering (credit @dedehai & @zalatnaicsongor)
// https://github.com/Aircoookie/WLED/pull/4115 and https://github.com/zalatnaicsongor/WLED/pull/1)
@@ -609,8 +609,10 @@ void BusPwm::show() {
duty -= deadTime << 1; // shorten duty of larger signal except if full on
}
}
if (_reversed) duty = maxBri - duty;
if (_reversed) {
if (i) hPoint += duty; // align start at time zero
duty = maxBri - duty;
}
#ifdef ESP8266
//stopWaveform(_pins[i]); // can cause the waveform to miss a cycle. instead we risk crossovers.
startWaveformClockCycles(_pins[i], duty, analogPeriod - duty, 0, i ? _pins[0] : -1, hPoint, false);
@@ -625,7 +627,8 @@ void BusPwm::show() {
ledc_update_duty((ledc_mode_t)gr, (ledc_channel_t)ch);
#endif
hPoint += duty + (_reversed ? -1 : 1) * deadTime; // offset to cascade the signals
if (!_reversed) hPoint += duty;
hPoint += deadTime; // offset to cascade the signals
if (hPoint >= maxBri) hPoint -= maxBri; // offset is out of bounds, reset
}
}