E30 M3 Tach output solution #907 (#1203)

* Update tachometer.cpp

Initial implementation of E30 M3 Tach output solution #907, unit_test plus debugging next

* tacho unit tests

First successfull unit test for tachometer

* RAM adjustment so it would link

* refactoring tacho, broken!

* starting to make some progress...still fails after a few seconds

* Rework with SW PWM

* Update after code review

* unit_test update

* First working unit_test

* Update .gitignore

* Update engine_controller.cpp

* Update engine_controller.cpp

* Update tachometer.h

* Update test_tacho.cpp

Co-authored-by: rusefi <rusefi@users.noreply.github.com>

firmware/controllers/gauges/tachometer.cpp

@@ -12,31 +12,69 @@
 
 #include "tachometer.h"
 #include "trigger_central.h"
-
+#include "pwm_generator.h"
 
 EXTERN_ENGINE;
 
-static scheduling_s tachTurnSignalOff;
+static SimplePwm tachControl("tach"); 
+static float tachFreq;  
+static float duty;   
 
-static void turnTachPinLow(void *) {
-	enginePins.tachOut.setLow();
+#if EFI_UNIT_TEST
+float getTachFreq(void) {
+	return tachFreq;
 }
 
+float getTachDuty(void) {
+	return duty;
+}
+#endif
+
 static void tachSignalCallback(trigger_event_e ckpSignalType,
 		uint32_t index, efitick_t edgeTimestamp DECLARE_ENGINE_PARAMETER_SUFFIX) {
-	UNUSED(ckpSignalType);
-	if (index != (uint32_t)engineConfiguration->tachPulseTriggerIndex) {
+	// only process at index configured to avoid too much cpu time for index 0?
+	if (index != (uint32_t)CONFIG(tachPulseTriggerIndex)) {
 		return;
 	}
-	enginePins.tachOut.setHigh();
-	float durationMs;
-	if (engineConfiguration->tachPulseDurationAsDutyCycle) {
-		// todo: implement tachPulseDurationAsDutyCycle
-		durationMs = engineConfiguration->tachPulseDuractionMs;
-	} else {
-		durationMs = engineConfiguration->tachPulseDuractionMs;
+
+#if EFI_UNIT_TEST
+	printf("tachSignalCallback(%d %d)\n", ckpSignalType, index);
+	printf("Current RPM: %d\n",GET_RPM());
+	UNUSED(edgeTimestamp);
+#else
+	UNUSED(ckpSignalType);
+	UNUSED(edgeTimestamp);
+#endif
+
+	// How many tach pulse periods do we have?
+	int periods = CONFIG(tachPulsePerRev);
+
+	if(periods == 0){
+		warning(CUSTOM_ERR_6709,"Check Tachometer Pulse per Rev!");
+		return;
 	}
-	engine->executor.scheduleForLater(&tachTurnSignalOff, (int)MS2US(durationMs), &turnTachPinLow);
+
+	// What is the angle per tach output period?
+	float cycleTimeMs = 60000.0 / GET_RPM();
+	float periodTimeMs = cycleTimeMs / periods;
+	tachFreq = 1000.0 / periodTimeMs;
+	
+	if (CONFIG(tachPulseDurationAsDutyCycle)) {
+		// Simple case - duty explicitly set
+		duty = CONFIG(tachPulseDuractionMs);
+	} else {
+		// Constant high-time mode - compute the correct duty cycle
+		duty = CONFIG(tachPulseDuractionMs) / periodTimeMs;
+	}
+
+	// In case Freq is under 1Hz, we stop pwm to avoid warnings!
+	if (tachFreq < 1.0) {
+		tachFreq = NAN;
+	}
+	
+	tachControl.setSimplePwmDutyCycle(duty);	
+	tachControl.setFrequency(tachFreq);
+
 }
 
 void initTachometer(DECLARE_ENGINE_PARAMETER_SIGNATURE) {
@@ -44,11 +82,14 @@ void initTachometer(DECLARE_ENGINE_PARAMETER_SIGNATURE) {
 		return;
 	}
 
-	enginePins.tachOut.initPin("Tachometer", CONFIG(tachOutputPin), &CONFIG(tachOutputPinMode));
+	startSimplePwmExt(&tachControl,
+				"Tachometer",
+				&engine->executor,
+				CONFIG(tachOutputPin),
+				&enginePins.tachOut,
+				NAN, 0.1, (pwm_gen_callback*)applyPinState);
 
 #if EFI_SHAFT_POSITION_INPUT
 	addTriggerEventListener(tachSignalCallback, "tach", engine);
 #endif /* EFI_SHAFT_POSITION_INPUT */
 }
-
-

unit_tests/tests/test_tacho.cpp

@@ -0,0 +1,41 @@
+#include "engine_test_helper.h"
+
+extern WarningCodeState unitTestWarningCodeState;
+extern float getTachFreq(void);
+extern float getTachDuty(void);
+
+TEST(tachometer, testPulsePerRev) {
+    // This engine has a tach pin set - we need that
+    WITH_ENGINE_TEST_HELPER(BMW_E34);
+
+    // We don't actually care about ign/inj at all, just tach
+    engineConfiguration->isInjectionEnabled = false;
+    engineConfiguration->isIgnitionEnabled = false;
+
+    // Configure tach pulse count
+    // 5 PPR, 25% duty
+    engineConfiguration->tachPulsePerRev = 4;
+    engineConfiguration->tachPulseDuractionMs = 0.5f;
+    engineConfiguration->tachPulseDurationAsDutyCycle = true;
+    engineConfiguration->tachPulseTriggerIndex = 0;
+
+    // Set predictable trigger settings
+    engineConfiguration->trigger.customTotalToothCount = 8;
+    engineConfiguration->trigger.customSkippedToothCount = 0;
+    engineConfiguration->useOnlyRisingEdgeForTrigger = false;
+    engineConfiguration->ambiguousOperationMode = FOUR_STROKE_CAM_SENSOR;
+	eth.applyTriggerWaveform();
+
+    // get the engine running - 6 revolutions
+    eth.fireTriggerEvents(48);
+
+    // ensure engine speed and position
+	ASSERT_EQ(1500,  GET_RPM()) << "RPM";
+	ASSERT_EQ(15,  engine->triggerCentral.triggerState.getCurrentIndex()) << "index #1";
+    ASSERT_EQ(engine->triggerCentral.triggerState.shaft_is_synchronized, true);
+    ASSERT_EQ(100,getTachFreq());
+    ASSERT_EQ(0.5,getTachDuty());
+std::cerr << "Tach Freq: " << getTachFreq() << "\n" << std::endl;
+std::cerr << "Tach Duty: " << getTachDuty() << "\n" << std::endl;
+ 
+}

unit_tests/tests/tests.mk

@@ -33,6 +33,7 @@ TESTS_SRC_CPP = \
 	tests/test_pid_auto.cpp \
 	tests/test_pid.cpp \
 	tests/test_accel_enrichment.cpp \
+	tests/test_tacho.cpp \
 	tests/test_gpiochip.cpp \
 	tests/test_multispark.cpp \
 	tests/sensor/basic_sensor.cpp \