fix 36-2-1 trigger (#4645)

* fix

* test files

* test real 4b11

* test.mk

* better angle error math

* test GM too

* changelog

firmware/CHANGELOG.md

@@ -39,6 +39,7 @@ Release template (copy/paste this for new release):
 ### Fixed
  - Fuel Priming reset fix #4627
  - Slower than expected RPM information was slowing engine start #4629
+ - Fix 36-2-1 trigger (Mitsubishi 4B11, etc) #4635
 
 ## September 2022 Release - "Day 203"
 

firmware/controllers/trigger/decoders/trigger_mitsubishi.cpp

@@ -84,6 +84,7 @@ void initialize36_2_1_1(TriggerWaveform *s) {
 	s->setSecondTriggerSynchronizationGap(1); // redundancy
 }
 
+// Mitsubishi 4B11
 void initialize36_2_1(TriggerWaveform *s) {
 	s->initialize(FOUR_STROKE_CRANK_SENSOR, SyncEdge::RiseOnly);
 	s->tdcPosition = 90;
@@ -94,16 +95,16 @@ void initialize36_2_1(TriggerWaveform *s) {
 
 	float oneTooth = 720 / totalTeethCount;
 
-	float offset = (36 - 17 - 2 - 16) * oneTooth;
-
-	addSkippedToothTriggerEvents(TriggerWheel::T_PRIMARY, s, totalTeethCount, 0, toothWidth, /*offset*/offset, engineCycle,
-			NO_LEFT_FILTER, offset + 17 * oneTooth + 1);
-
-	offset += (17 + 2) * oneTooth;
+	float offset = (36 - 16 - 2 - 17) * oneTooth;
 
 	addSkippedToothTriggerEvents(TriggerWheel::T_PRIMARY, s, totalTeethCount, 0, toothWidth, /*offset*/offset, engineCycle,
 			NO_LEFT_FILTER, offset + 16 * oneTooth + 1);
 
+	offset += (16 + 2) * oneTooth;
+
+	addSkippedToothTriggerEvents(TriggerWheel::T_PRIMARY, s, totalTeethCount, 0, toothWidth, /*offset*/offset, engineCycle,
+			NO_LEFT_FILTER, offset + 17 * oneTooth + 1);
+
 
 	s->setTriggerSynchronizationGap(3);
 	s->setSecondTriggerSynchronizationGap(1); // redundancy

firmware/controllers/trigger/trigger_central.cpp

@@ -703,7 +703,14 @@ void TriggerCentral::handleShaftSignal(trigger_event_e signal, efitick_t timesta
 		// basically, check that the tooth width is correct
 		auto estimatedCurrentPhase = getCurrentEnginePhase(timestamp);
 		if (estimatedCurrentPhase) {
-			triggerToothAngleError = expectedNextPhase - estimatedCurrentPhase.Value;
+			float angleError = expectedNextPhase - estimatedCurrentPhase.Value;
+
+			float cycle = getEngineState()->engineCycle;
+			while (angleError < -cycle / 2) {
+				angleError += cycle;
+			}
+
+			triggerToothAngleError = angleError;
 		}
 
 		// Record precise time and phase of the engine. This is used for VVT decode, and to check that the

unit_tests/tests/tests.mk

@@ -13,6 +13,7 @@ TESTS_SRC_CPP = \
 	tests/trigger/test_real_cranking_miata_na6.cpp \
 	tests/trigger/test_real_cranking_nissan_vq40.cpp \
 	tests/trigger/test_trigger_skipped_wheel.cpp \
+	tests/trigger/test_real_4b11.cpp \
 	tests/trigger/test_real_volkswagen.cpp \
 	tests/trigger/test_real_nb2_cranking.cpp \
 	tests/trigger/test_real_gm_24x.cpp \

unit_tests/tests/trigger/test_real_4b11.cpp

@@ -0,0 +1,42 @@
+// Mitsubishi 4B11 trigger pattern
+// Crank: 36-2-1
+// Cam: Single tooth (half moon)
+
+#include "pch.h"
+
+#include "logicdata_csv_reader.h"
+
+TEST(real4b11, running) {
+	CsvReader reader(1, /* vvtCount */ 0);
+
+	reader.open("tests/trigger/resources/4b11-running.csv");
+	EngineTestHelper eth(TEST_ENGINE);
+	engineConfiguration->isFasterEngineSpinUpEnabled = true;
+	engineConfiguration->alwaysInstantRpm = true;
+
+	eth.setTriggerType(TT_36_2_1);
+
+	int eventCount = 0;
+	bool gotRpm = false;
+
+	while (reader.haveMore()) {
+		reader.processLine(&eth);
+		eventCount++;
+		engine->rpmCalculator.onSlowCallback();
+
+		// Expect that all teeth are in the correct spot
+		float angleError = getTriggerCentral()->triggerToothAngleError;
+		EXPECT_TRUE(angleError < 3 && angleError > -3) << "tooth angle of " << angleError << " at timestamp " << (getTimeNowNt() / 1e8);
+
+		auto rpm = Sensor::getOrZero(SensorType::Rpm);
+		if (!gotRpm && rpm) {
+			gotRpm = true;
+
+			// We should get first RPM on exactly the first sync point - this means the instant RPM pre-sync event copy all worked OK
+			EXPECT_EQ(eventCount, 30);
+			EXPECT_NEAR(rpm, 1436.23f, 0.1);
+		}
+	}
+
+	ASSERT_EQ(0, eth.recentWarnings()->getCount());
+}

unit_tests/tests/trigger/test_real_gm_24x.cpp

@@ -21,6 +21,10 @@ TEST(crankingGm24x, gmRealCrankingFromFile) {
 
 		engine->rpmCalculator.onSlowCallback();
 
+		// Expect that all teeth are in the correct spot
+		float angleError = getTriggerCentral()->triggerToothAngleError;
+		EXPECT_TRUE(angleError < 3 && angleError > -3) << "tooth angle of " << angleError << " at timestamp " << (getTimeNowNt() / 1e8);
+
 		auto rpm = Sensor::getOrZero(SensorType::Rpm);
 		if (!gotRpm && rpm) {
 			gotRpm = true;