diff --git a/firmware/controllers/trigger/trigger_emulator_algo.cpp b/firmware/controllers/trigger/trigger_emulator_algo.cpp
index 33d2e57860..04c53b312f 100644
--- a/firmware/controllers/trigger/trigger_emulator_algo.cpp
+++ b/firmware/controllers/trigger/trigger_emulator_algo.cpp
@@ -15,6 +15,10 @@
  */
 #include "global.h"
 
+int getPreviousIndex(const int currentIndex, const int size) {
+	return (currentIndex + size - 1) % size;
+}
+
 #if EFI_EMULATE_POSITION_SENSORS || defined(__DOXYGEN__)
 
 #include "engine.h"
@@ -32,7 +36,7 @@ EXTERN_ENGINE
 ;
 
 void TriggerEmulatorHelper::handleEmulatorCallback(PwmConfig *state, int stateIndex) {
-	int prevIndex = (stateIndex + state->phaseCount - 1) % state->phaseCount;
+	int prevIndex = getPreviousIndex(stateIndex, state->phaseCount);
 
 	pin_state_t primaryWheelState = state->multiWave.getChannelState(/* channelIndex*/ 0, /*phaseIndex*/prevIndex);
 	pin_state_t newPrimaryWheelState = state->multiWave.getChannelState(/* channelIndex*/ 0, /*phaseIndex*/stateIndex);
@@ -46,17 +50,14 @@ void TriggerEmulatorHelper::handleEmulatorCallback(PwmConfig *state, int stateIn
 	// todo: code duplication with TriggerStimulatorHelper::feedSimulatedEvent?
 
 	if (primaryWheelState != newPrimaryWheelState) {
-		primaryWheelState = newPrimaryWheelState;
 		hwHandleShaftSignal(primaryWheelState ? SHAFT_PRIMARY_RISING : SHAFT_PRIMARY_FALLING);
 	}
 
 	if (secondaryWheelState != newSecondaryWheelState) {
-		secondaryWheelState = newSecondaryWheelState;
 		hwHandleShaftSignal(secondaryWheelState ? SHAFT_SECONDARY_RISING : SHAFT_SECONDARY_FALLING);
 	}
 
 	if (thirdWheelState != new3rdWheelState) {
-		thirdWheelState = new3rdWheelState;
 		hwHandleShaftSignal(thirdWheelState ? SHAFT_3RD_RISING : SHAFT_3RD_FALLING);
 	}
 
diff --git a/firmware/controllers/trigger/trigger_emulator_algo.h b/firmware/controllers/trigger/trigger_emulator_algo.h
index cf093c06f1..98c64a9146 100644
--- a/firmware/controllers/trigger/trigger_emulator_algo.h
+++ b/firmware/controllers/trigger/trigger_emulator_algo.h
@@ -19,4 +19,6 @@ public:
 
 void initTriggerEmulatorLogic(Logging *sharedLogger DECLARE_ENGINE_PARAMETER_SUFFIX);
 
+int getPreviousIndex(const int currentIndex, const int size);
+
 #endif /* TRIGGER_EMULATOR_ALGO_H_ */
diff --git a/firmware/controllers/trigger/trigger_simulator.cpp b/firmware/controllers/trigger/trigger_simulator.cpp
index 231ae1709e..8daa037b0b 100644
--- a/firmware/controllers/trigger/trigger_simulator.cpp
+++ b/firmware/controllers/trigger/trigger_simulator.cpp
@@ -33,21 +33,21 @@ void TriggerStimulatorHelper::feedSimulatedEvent(TriggerState *state, TriggerSha
 		DECLARE_ENGINE_PARAMETER_SUFFIX) {
 	efiAssertVoid(CUSTOM_ERR_6593, shape->getSize() > 0, "size not zero");
 	int stateIndex = i % shape->getSize();
-	int prevIndex = (stateIndex + shape->getSize() - 1 ) % shape->getSize();
+	int prevIndex = getPreviousIndex(stateIndex, shape->getSize());
 
 
 	int loopIndex = i / shape->getSize();
 
 	int time = (int) (SIMULATION_CYCLE_PERIOD * (loopIndex + shape->wave.getSwitchTime(stateIndex)));
 
-	bool primaryWheelState = shape->wave.getChannelState(0, prevIndex);
-	bool newPrimaryWheelState = shape->wave.getChannelState(0, stateIndex);
+	pin_state_t primaryWheelState = shape->wave.getChannelState(0, prevIndex);
+	pin_state_t newPrimaryWheelState = shape->wave.getChannelState(0, stateIndex);
 
-	bool secondaryWheelState = shape->wave.getChannelState(1, prevIndex);
-	bool newSecondaryWheelState = shape->wave.getChannelState(1, stateIndex);
+	pin_state_t secondaryWheelState = shape->wave.getChannelState(1, prevIndex);
+	pin_state_t newSecondaryWheelState = shape->wave.getChannelState(1, stateIndex);
 
-	bool thirdWheelState = shape->wave.getChannelState(2, prevIndex);
-	bool new3rdWheelState = shape->wave.getChannelState(2, stateIndex);
+	pin_state_t thirdWheelState = shape->wave.getChannelState(2, prevIndex);
+	pin_state_t new3rdWheelState = shape->wave.getChannelState(2, stateIndex);
 
 #if EFI_UNIT_TEST || defined(__DOXYGEN__)
 	if (printTriggerDebug) {