harley_acr.cpp

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// Controller for Harley Davidson Automatic Compression Release
//
// To make the starter's job easier, these bike engines have a solenoid
// that dumps cylinder pressure to atmosphere until the engine is spinning
// fast enough to actually have a chance at starting.
// We open the valve the instant the engine starts moving, then close it
// once the specified number of revolutions have occurred, plus some engine phase.
// This allows the valve to close at just the right moment that you don't get a
// weird half-charge if it closed mid way up on a compression stroke.
 
#include "pch.h"
 
#if EFI_HD_ACR
 
static bool getAcrState() {
    bool engineMovedRecently = getTriggerCentral()->engineMovedRecently();
    engine->engineState.acrEngineMovedRecently = engineMovedRecently;
    auto currentPhase = getTriggerCentral()->getCurrentEnginePhase(getTimeNowNt());
    if (!currentPhase) {
        return engineMovedRecently;
    }
 
    // Turn off the valve if the engine isn't moving - no sense wasting power on a stopped engine
    if (!engineMovedRecently) {
        return false;
    }
 
    int revCount = getTriggerCentral()->triggerState.getSynchronizationCounter();
    if (revCount > engineConfiguration->acrRevolutions) {
        // Enough revs have elapsed that we're done with ACR
        return false;
    } else if (revCount == engineConfiguration->acrRevolutions) {
        float wrappedPhase = currentPhase.Value > 360 ? currentPhase.Value - 360 : currentPhase.Value;
 
        // We're on the rev where ACR should be disabled part way through
        if (wrappedPhase > engineConfiguration->acrDisablePhase) {
            return false;
        } else {
            // Not enough phase elapsed, ACR still active
            return true;
        }
    } else {
        // ACR active - not enough revs completed
        return true;
    }
}
 
void HarleyAcr::onSlowCallback() {
    // skip if no pin
    if (!isBrainPinValid(engineConfiguration->acrPin)) {
        m_active = false;
        return;
    }
 
    bool acrState = getAcrState();
    engine->engineState.acrActive = acrState;
    enginePins.harleyAcr.setValue(acrState);
    enginePins.harleyAcr2.setValue(acrState);
    m_active = acrState;
}
 
void HarleyAcr::updateAcr() {
    onSlowCallback();
}
 
bool HarleyAcr::isActive() const {
    return m_active;
}
 
#endif // EFI_HD_ACR