ignition timing clamping settings

firmware/CHANGELOG.md

@@ -33,6 +33,7 @@ Release template (copy/paste this for new release):
  - injector duty cycle limited at 50% for GDI engines #5416
  - STM32Cube v2.14 #5418
  - turning coils and injectors off in case of extremely unexpected errors #5429
+ - Configurable ignition timing limits, adding safety particularly for engines running wasted spark with a large cam FOME#211
 
 ### Fixed
  - fuel_pump_control is accessible as getOutput("isFuelPumpOn") in Lua #5239 

firmware/controllers/engine_cycle/spark_logic.cpp

@@ -92,6 +92,12 @@ static void prepareCylinderIgnitionSchedule(angle_t dwellAngleDuration, floatms_
 		finalIgnitionTiming -= 720;
 	}
 
+	// Clamp the final ignition timing to the configured limits
+	// finalIgnitionTiming is deg BTDC
+	// minimumIgnitionTiming limits maximium retard
+	// maximumIgnitionTiming limits maximum advance
+	finalIgnitionTiming = clampF(engineConfiguration->minimumIgnitionTiming, finalIgnitionTiming, engineConfiguration->maximumIgnitionTiming);
+
     engine->outputChannels.ignitionAdvanceCyl[event->cylinderIndex] = finalIgnitionTiming;
 
 	angle_t sparkAngle =

unit_tests/tests/trigger/test_trigger_decoder.cpp

@@ -84,6 +84,8 @@ TEST(trigger, test1995FordInline6TriggerDecoder) {
 
 	EngineTestHelper eth(engine_type_e::FORD_INLINE_6_1995);
 	engineConfiguration->isFasterEngineSpinUpEnabled = false;
+
+	engineConfiguration->minimumIgnitionTiming = -15;
 	setWholeTimingTable(-13);
 
 	Sensor::setMockValue(SensorType::Iat, 49.579071f);
@@ -190,6 +192,7 @@ TEST(misc, testRpmCalculator) {
 
 	efiAssertVoid(ObdCode::CUSTOM_ERR_6670, engineConfiguration!=NULL, "null config in engine");
 
+	engineConfiguration->minimumIgnitionTiming = -15;
 	setWholeTimingTable(-13);
 
 	engineConfiguration->trigger.customTotalToothCount = 8;