trailing spark scheduling

firmware/controllers/algo/engine2.cpp

@@ -171,6 +171,10 @@ void EngineState::periodicFastCallback(DECLARE_ENGINE_PARAMETER_SIGNATURE) {
 
 	float ignitionLoad = getIgnitionLoad(PASS_ENGINE_PARAMETER_SIGNATURE);
 	timingAdvance = getAdvance(rpm, ignitionLoad PASS_ENGINE_PARAMETER_SUFFIX);
+
+	// TODO: calculate me from a table!
+	trailingSparkAngle = 10;
+
 	multispark.count = getMultiSparkCount(rpm PASS_ENGINE_PARAMETER_SUFFIX);
 
 #if EFI_LAUNCH_CONTROL

firmware/controllers/algo/engine_state.h

@@ -47,6 +47,10 @@ class EngineState : public engine_state2_s {
 	 * timing advance is angle distance before Top Dead Center (TDP), i.e. "10 degree timing advance" means "happens 10 degrees before TDC"
 	 */
 	angle_t timingAdvance = 0;
+
+	// Angle between firing the main (primary) spark and the secondary (trailing) spark
+	angle_t trailingSparkAngle = 0;
+
 	// fuel-related;
 	float fuelCutoffCorrection = 0;
 	efitick_t coastingFuelCutStartTime = 0;

firmware/controllers/algo/event_registry.h

@@ -99,6 +99,9 @@ class IgnitionEvent {
 	scheduling_s dwellStartTimer;
 	AngleBasedEvent sparkEvent;
 
+	scheduling_s trailingSparkCharge;
+	scheduling_s trailingSparkFire;
+
 	// How many additional sparks should we fire after the first one?
 	// For single sparks, this should be zero.
 	uint8_t sparksRemaining = 0;

firmware/controllers/engine_controller.cpp

@@ -698,7 +698,7 @@ void initEngineContoller(DECLARE_ENGINE_PARAMETER_SUFFIX) {
  * UNUSED_SIZE constants.
  */
 #ifndef RAM_UNUSED_SIZE
-#define RAM_UNUSED_SIZE 1400
+#define RAM_UNUSED_SIZE 1000
 #endif
 #ifndef CCM_UNUSED_SIZE
 #define CCM_UNUSED_SIZE 300

firmware/controllers/engine_cycle/spark_logic.cpp

@@ -128,6 +128,14 @@ static void prepareCylinderIgnitionSchedule(angle_t dwellAngleDuration, floatms_
 #endif /* FUEL_MATH_EXTREME_LOGGING */
 }
 
+static void chargeTrailingSpark(IgnitionOutputPin* pin) {
+	pin->setValue(1);
+}
+
+static void fireTrailingSpark(IgnitionOutputPin* pin) {
+	pin->setValue(0);
+}
+
 void fireSparkAndPrepareNextSchedule(IgnitionEvent *event) {
 	for (int i = 0; i< MAX_OUTPUTS_FOR_IGNITION;i++) {
 		IgnitionOutputPin *output = event->outputs[i];
@@ -186,8 +194,7 @@ if (engineConfiguration->debugMode == DBG_DWELL_METRIC) {
 	}
 
 	// If there are more sparks to fire, schedule them
-	if (event->sparksRemaining > 0)
-	{
+	if (event->sparksRemaining > 0) {
 		event->sparksRemaining--;
 
 		efitick_t nextDwellStart = nowNt + engine->engineState.multispark.delay;
@@ -196,9 +203,16 @@ if (engineConfiguration->debugMode == DBG_DWELL_METRIC) {
 		// We can schedule both of these right away, since we're going for "asap" not "particular angle"
 		engine->executor.scheduleByTimestampNt(&event->dwellStartTimer, nextDwellStart, { &turnSparkPinHigh, event });
 		engine->executor.scheduleByTimestampNt(&event->sparkEvent.scheduling, nextFiring, { fireSparkAndPrepareNextSchedule, event });
-	}
-	else
-	{
+	} else {
+		if (CONFIG(enableTrailingSparks)) {
+			// Trailing sparks are enabled - schedule an event for the corresponding trailing coil
+			scheduleByAngle(
+				&event->trailingSparkFire, nowNt, ENGINE(engineState.trailingSparkAngle),
+				{ &fireTrailingSpark, &enginePins.trailingCoils[event->cylinderNumber] }
+				PASS_ENGINE_PARAMETER_SUFFIX
+			);
+		}
+
 		// If all events have been scheduled, prepare for next time.
 		prepareCylinderIgnitionSchedule(dwellAngleDuration, sparkDwell, event PASS_ENGINE_PARAMETER_SUFFIX);
 	}
@@ -269,6 +283,15 @@ void turnSparkPinHigh(IgnitionEvent *event) {
 			startDwellByTurningSparkPinHigh(event, output);
 		}
 	}
+
+	if (CONFIG(enableTrailingSparks)) {
+		// Trailing sparks are enabled - schedule an event for the corresponding trailing coil
+		scheduleByAngle(
+			&event->trailingSparkCharge, nowNt, ENGINE(engineState.trailingSparkAngle),
+			{ &chargeTrailingSpark, &enginePins.trailingCoils[event->cylinderNumber] }
+			PASS_ENGINE_PARAMETER_SUFFIX
+		);
+	}
 }
 
 static bool assertNotInIgnitionList(AngleBasedEvent *head, AngleBasedEvent *element) {

firmware/controllers/system/efi_gpio.h

@@ -209,6 +209,7 @@ class EnginePins {
 
 	InjectorOutputPin injectors[MAX_CYLINDER_COUNT];
 	IgnitionOutputPin coils[MAX_CYLINDER_COUNT];
+	IgnitionOutputPin trailingCoils[MAX_CYLINDER_COUNT];
 	NamedOutputPin auxValve[AUX_DIGITAL_VALVE_COUNT];
 	OutputPin tcuSolenoids[TCU_SOLENOID_COUNT];
 

firmware/integration/rusefi_config.txt

@@ -536,7 +536,7 @@ bit enableFan1WithAc;+Turn on this fan when AC is on.
 bit enableFan2WithAc;+Turn on this fan when AC is on.
 bit disableFan1WhenStopped;+Inhibit operation of this fan while the engine is not running.
 bit disableFan2WhenStopped;+Inhibit operation of this fan while the engine is not running.
-bit unused_294_8
+bit enableTrailingSparks;+Enable secondary spark outputs that fire after the primary (rotaries, twin plug engines).
 bit isCJ125Verbose;enable cj125verbose/disable cj125verbose
 bit cj125isUaDivided;+Is your UA CJ125 output wired to MCU via resistor divider? Ua can go over 3.3v but only at lambda >3, i.e very lean AFR above 44.1\nWhen exposed to free air and 17x gain, Ua will be 4.17 volt
 bit cj125isLsu49

unit_tests/tests/ignition_injection/test_ignition_scheduling.cpp

@@ -8,6 +8,8 @@
 #include "engine_test_helper.h"
 #include "spark_logic.h"
 
+using ::testing::_;
+
 TEST(ignition, twoCoils) {
 	WITH_ENGINE_TEST_HELPER(BMW_M73_F);
 
@@ -33,9 +35,65 @@ TEST(ignition, twoCoils) {
 
 	ASSERT_EQ(engine->ignitionEvents.elements[3].sparkAngle, 3 * 720 / 12);
 	ASSERT_EQ((void*)engine->ignitionEvents.elements[3].outputs[0], (void*)&enginePins.coils[6]);
+}
 
+TEST(ignition, trailingSpark) {
+	WITH_ENGINE_TEST_HELPER(TEST_ENGINE);
 
-}
+	EXPECT_CALL(eth.mockAirmass, getAirmass(_))
+		.WillRepeatedly(Return(AirmassResult{0.1008f, 50.0f}));
+
+	setupSimpleTestEngineWithMafAndTT_ONE_trigger(&eth);
+	CONFIG(specs.cylindersCount) = 1;
+	CONFIG(specs.firingOrder) = FO_1;
+	CONFIG(isInjectionEnabled) = false;
+	CONFIG(isIgnitionEnabled) = true;
+
+	// Fire trailing spark 10 degrees after main spark
+	ENGINE(engineState.trailingSparkAngle) = 10;
+
+	engineConfiguration->injectionMode = IM_SEQUENTIAL;
+
+	eth.fireTriggerEventsWithDuration(20);
+	// still no RPM since need to cycles measure cycle duration
+	eth.fireTriggerEventsWithDuration(20);
+	eth.clearQueue();
+
+	/**
+	 * Trigger up - scheduling fuel for full engine cycle
+	 */
+	eth.fireRise(20);
 
+	// Primary coil should be high
+	EXPECT_EQ(enginePins.coils[0].getLogicValue(), true);
+	EXPECT_EQ(enginePins.trailingCoils[0].getLogicValue(), false);
 
+	// Should be a TDC callback + spark firing
+	EXPECT_EQ(engine->executor.size(), 2);
 
+	// execute all actions
+	eth.clearQueue();
+
+	// Primary and secondary coils should be low - primary just fired
+	EXPECT_EQ(enginePins.coils[0].getLogicValue(), false);
+	EXPECT_EQ(enginePins.trailingCoils[0].getLogicValue(), false);
+
+	// Now enable trailing sparks
+	CONFIG(enableTrailingSparks) = true;
+
+	// Fire trigger fall - should schedule ignition chargings (rising edges)
+	eth.fireFall(20);
+	eth.clearQueue();
+
+	// Primary and secondary coils should be low
+	EXPECT_EQ(enginePins.coils[0].getLogicValue(), true);
+	EXPECT_EQ(enginePins.trailingCoils[0].getLogicValue(), true);
+
+	// Fire trigger rise - should schedule ignition firings
+	eth.fireRise(20);
+	eth.clearQueue();
+
+	// Primary and secondary coils should be low
+	EXPECT_EQ(enginePins.coils[0].getLogicValue(), false);
+	EXPECT_EQ(enginePins.trailingCoils[0].getLogicValue(), false);
+}