Refactor ISR to avoid a divide, fix missing retune on CC reset, fix o…

…scillator reset on masterclock rollover.

CRIO.cpp

@@ -15,7 +15,7 @@ DigitalPin<coilOutPin> _coilOutPin(OUTPUT, LOW);
 DigitalPin<diagOutPin> _diagOutPin(OUTPUT, LOW);
 DigitalPin<speakerOutPin> _speakerOutPin(OUTPUT, LOW);
 
-CRIO::CRIO() : scheduled(false), slipTick(false), _oneShotPulseUs(0), _multiShotPulses(0), _pulseState(0), pw(pulseWindowUs), maxPitch(maxMidiPitch), breakoutUs(minBreakoutUs), _ticksSinceLastPulse(0) {
+CRIO::CRIO() : scheduled(false), _remainingPulseUs(0), _pulseState(0), pw(pulseWindowUs), maxPitch(maxMidiPitch), breakoutUs(minBreakoutUs), _ticksSinceLastPulse(0), handlePulsePtr(&CRIO::handleNoPulse) {
 }
 
 bool CRIO::percussionEnabled() {
@@ -41,59 +41,54 @@ inline void CRIO::pulseOff() {
 }
 
 bool CRIO::handlePulse() {
+ return (this->*handlePulsePtr)();
+}
+
+bool CRIO::handleNoPulse() {
  ++_ticksSinceLastPulse;
- if (scheduled) {
- return false;
- }
- if (_multiShotPulses == 0) {
- if (_oneShotPulseUs) {
- pulseOn();
- delayMicroseconds(_oneShotPulseUs);
- pulseOff();
- _oneShotPulseUs = 0;
- return true;
- }
- pulseOff();
- return false;
- }
+ return false;
+}
+
+bool CRIO::handleLongPulse() {
  pulseOn();
- --_multiShotPulses;
+ ++_ticksSinceLastPulse;
+ _remainingPulseUs -= masterClockPeriodUs;
+ if (_remainingPulseUs <= masterClockPeriodUs) {
+ handlePulsePtr = &CRIO::handleShortPulse;
+ }
  return false;
 }
 
-void CRIO::startPulse() {
- if (scheduled) {
- _ticksSinceLastPulse = 0;
- scheduled = false;
+bool CRIO::handleShortPulse() {
+ if (_remainingPulseUs) {
+ pulseOn();
+ delayMicroseconds(_remainingPulseUs);
+ pulseOff();
+ _remainingPulseUs = 0;
+ ++_ticksSinceLastPulse;
+ handlePulsePtr = &CRIO::handleNoPulse;
+ return true;
  }
+ pulseOff();
+ ++_ticksSinceLastPulse;
+ handlePulsePtr = &CRIO::handleNoPulse;
+ return false;
 }
 
 void CRIO::schedulePulse(cr_fp_t pulseUs) {
- if (scheduled) {
- return;
- }
  if (pulseUs == 0) {
  return;
  }
  if (_ticksSinceLastPulse < pulseGuardTicks) {
  return;
  }
- scheduled = true;
- _oneShotPulseUs = cr_pulse_t(roundFixed(pulseUs));
- if (_oneShotPulseUs >= cr_pulse_t(masterClockPeriodUs)) {
- _multiShotPulses = _oneShotPulseUs / masterClockPeriodUs;
- _oneShotPulseUs -= _multiShotPulses * masterClockPeriodUs;
+ _remainingPulseUs = cr_pulse_t(roundFixed(pulseUs));
+ if (_remainingPulseUs > masterClockPeriodUs) {
+ handlePulsePtr = &CRIO::handleLongPulse;
  } else {
- _multiShotPulses = 0;
- }
- if (_oneShotPulseUs) {
- if (_oneShotPulseUs > oneShotRemainderPulsePadUs) {
- ++_multiShotPulses;
- _oneShotPulseUs = 0;
- } else if (_oneShotPulseUs < oneShotPulsePadUs) { // cppcheck-suppress knownConditionTrueFalse
- _oneShotPulseUs = oneShotPulsePadUs;
- }
+ handlePulsePtr = &CRIO::handleShortPulse;
  }
+ _ticksSinceLastPulse = 0;
 }
 
 bool CRIO::pollPots() {

CRIO.h

@@ -19,8 +19,6 @@ const uint8_t lcdWidth = 16;
 const uint8_t lcdLines = 2;
 const uint8_t analogBits = 12;
 const cr_fp_t maxAnalogRead = cr_fp_t(1) / cr_fp_t(4095);
-const uint8_t oneShotPulsePadUs = 1;
-const uint8_t oneShotRemainderPulsePadUs = masterClockPeriodUs - oneShotPulsePadUs;
 const uint8_t potPins = 3;
 const uint8_t potSampleWindow = 16;
 
@@ -34,7 +32,6 @@ typedef struct {
 class CRIO {
  public:
  CRIO();
- void startPulse();
  void schedulePulse(cr_fp_t pulseUs);
  virtual bool handlePulse();
  virtual void updateLcd();
@@ -44,16 +41,18 @@ class CRIO {
  virtual bool percussionEnabled();
  virtual bool fixedPulseEnabled();
  bool scheduled;
- bool slipTick;
  cr_fp_t pw;
  uint8_t maxPitch;
  cr_fp_t breakoutUs;
 private:
+ bool handleShortPulse();
+ bool handleLongPulse();
+ bool handleNoPulse();
  void pulseOff();
  void pulseOn();
  bool _pulseState;
- cr_pulse_t _oneShotPulseUs;
- uint8_t _multiShotPulses;
+ bool (CRIO::*handlePulsePtr)(void);
+ cr_pulse_t _remainingPulseUs;
  uint16_t _ticksSinceLastPulse;
 };
 

CRMidi.cpp

@@ -187,6 +187,7 @@ void CRMidi::handleControlChange(byte channel, byte number, byte value) {
  break;
  case 121: // Reset All Controllers
  midiChannel->ResetCC();
+ requireRetune = true;
  break;
  case 95:
  // Set channel detune of 2nd oscillator in cents.

Oscillator.cpp

@@ -29,10 +29,11 @@ inline void Oscillator::_updateNextClock(cr_tick_t newNextClock) {
 }
 
 cr_tick_t Oscillator::TicksUntilTriggered(cr_tick_t masterClock, cr_tick_t clockRemainder) {
- if (masterClock <= _nextClock) {
+ if (_nextClock >= masterClock) {
  return _nextClock - masterClock;
  }
- return _nextClock + clockRemainder;
+ // account for 0th tick on rollover.
+ return _nextClock + (clockRemainder + 1);
 }
 
 bool Oscillator::Triggered(cr_tick_t masterClock) {

OscillatorController.cpp

@@ -21,6 +21,7 @@ OscillatorController::OscillatorController() {
  _controlClock = 0;
  _lfoClock = 0;
  _reschedulePending = false;
+ audibleOscillator = NULL;
  controlTriggered = true;
  tremoloLfo = _lfos;
  vibratoLfo = _lfos + 1;
@@ -78,7 +79,7 @@ void OscillatorController::RestartLFOs() {
  FOR_ALL_LFO(lfo->Restart());
 }
 
-void OscillatorController::Reschedule(Oscillator **audibleOscillator) {
+void OscillatorController::_Reschedule() {
  cr_tick_t minNextTriggeredTicks = masterClockMax;
  cr_tick_t clockRemainder = masterClockMax - _masterClock;
  FOR_ALL_OSC(
@@ -87,8 +88,8 @@ void OscillatorController::Reschedule(Oscillator **audibleOscillator) {
  nextTriggeredTicks = oscillator->SetNextTick(_masterClock);
  if (oscillator->audible) {
  // Always pick the highest frequency audible oscillator.
- if (*audibleOscillator == NULL || (oscillator->hz > (*audibleOscillator)->hz)) {
- *audibleOscillator = oscillator;
+ if (audibleOscillator == NULL || (oscillator->hz > audibleOscillator->hz)) {
+ audibleOscillator = oscillator;
  }
  }
  }
@@ -100,10 +101,11 @@ void OscillatorController::Reschedule(Oscillator **audibleOscillator) {
  _reschedulePending = false;
 }
 
-bool OscillatorController::Triggered(Oscillator **audibleOscillator) {
- *audibleOscillator = NULL;
+bool OscillatorController::Triggered() {
+ Tick();
+ audibleOscillator = NULL;
  if (_reschedulePending || _nextTriggeredOscillator->Triggered(_masterClock)) {
- Reschedule(audibleOscillator);
+ _Reschedule();
  return true;
  }
  return false;

OscillatorController.h

@@ -21,7 +21,7 @@ class OscillatorController {
  void Tick();
  void RestartLFOs();
  void ResetAll();
- bool Triggered(Oscillator **audibleOscillator);
+ bool Triggered();
  Oscillator *GetFreeOscillator();
  void ReturnFreeOscillator(Oscillator *oscillator);
  void SetMaxHz(cr_fp_t newMaxHz);
@@ -31,8 +31,9 @@ class OscillatorController {
  Lfo *tremoloLfo;
  Lfo *vibratoLfo;
  Lfo *configurableLfo;
+ Oscillator *audibleOscillator;
  private:
- void Reschedule(Oscillator **audibleOscillator);
+ void _Reschedule();
  Lfo _lfos[lfoCount];
  Oscillator _oscillators[oscillatorCount];
  cr_fp_t _maxHz;

chime_red2.ino

@@ -53,6 +53,7 @@ MIDI_CREATE_CUSTOM_INSTANCE(HardwareSerial, CR_SERIAL, MIDI, ChimeRedSettings);
 CR_IO crio;
 OscillatorController oc;
 CRMidi crmidi(&oc, &crio);
+void (*isrPtr)(void) = &nextISR;
 
 inline void handleNoteOn(byte channel, byte note, byte velocity) {
  crmidi.handleNoteOn(channel, note, velocity);
@@ -78,26 +79,22 @@ inline void resetAll() {
  crmidi.ResetAll();
 }
 
-void masterISR() {
- bool remainderPulse = crio.handlePulse();
- if (remainderPulse) {
- crio.slipTick = true;
- return;
- }
- Oscillator *audibleOscillator = NULL;
- oc.Tick();
- if (crio.slipTick) {
- oc.Triggered(&audibleOscillator);
- oc.Tick();
- oc.Triggered(&audibleOscillator);
- crio.slipTick = false;
+void slipTickISR() {
+ oc.Triggered();
+ oc.Triggered();
+ isrPtr = &nextISR;
+}
+
+void nextISR() {
+ // This ISR period was used to output pulse less than the ISR period - catch up on next ISR.
+ if (crio.handlePulse()) {
+ isrPtr = &slipTickISR;
  return;
  }
- if (oc.Triggered(&audibleOscillator)) {
- if (audibleOscillator) {
- cr_fp_t p = crmidi.Modulate(audibleOscillator);
+ if (oc.Triggered()) {
+ if (oc.audibleOscillator) {
+ cr_fp_t p = crmidi.Modulate(oc.audibleOscillator);
  crio.schedulePulse(p);
- crio.startPulse();
  }
  return;
  }
@@ -109,6 +106,10 @@ void masterISR() {
  }
 }
 
+void masterISR() {
+ (*isrPtr)();
+}
+
 void enableMidi() {
  START_ISR(masterClockHz, masterISR);
  MIDI.setHandleNoteOn(handleNoteOn);

types.h

@@ -26,7 +26,7 @@
 #include <FixedPointsCommon.h>
 
 typedef uint16_t cr_pulse_t;
-typedef uint16_t cr_tick_t;
+typedef uint32_t cr_tick_t;
 typedef uint32_t cr_slowtick_t;
 typedef SFixed<16, 15> cr_fp_t;