diff --git a/firmware/config/stm32f4ems/efifeatures.h b/firmware/config/stm32f4ems/efifeatures.h
index fb424d1c8d..b69d88d2f8 100644
--- a/firmware/config/stm32f4ems/efifeatures.h
+++ b/firmware/config/stm32f4ems/efifeatures.h
@@ -14,6 +14,8 @@
 
 #define EFI_FSIO TRUE
 
+#define EFI_CDM_INTEGRATION TRUE
+
 #define EFI_TEXT_LOGGING TRUE
 
 #define EFI_PWM_TESTER FALSE
diff --git a/firmware/controllers/algo/engine_configuration.cpp b/firmware/controllers/algo/engine_configuration.cpp
index c33cda8f19..eafdc898d1 100644
--- a/firmware/controllers/algo/engine_configuration.cpp
+++ b/firmware/controllers/algo/engine_configuration.cpp
@@ -311,6 +311,8 @@ void prepareVoidConfiguration(engine_configuration_s *engineConfiguration) {
 	engineConfiguration->flexFuelSensor = GPIO_UNASSIGNED;
 	engineConfiguration->test557pin = GPIO_UNASSIGNED;
 
+	boardConfiguration->cdmInputPin = GPIO_UNASSIGNED;
+
 	boardConfiguration->joystickCenterPin = GPIO_UNASSIGNED;
 	boardConfiguration->joystickAPin = GPIO_UNASSIGNED;
 	boardConfiguration->joystickBPin = GPIO_UNASSIGNED;
diff --git a/firmware/hw_layer/cdm_ion_sense.cpp b/firmware/hw_layer/cdm_ion_sense.cpp
index 7ae942aced..1ad2d7a755 100644
--- a/firmware/hw_layer/cdm_ion_sense.cpp
+++ b/firmware/hw_layer/cdm_ion_sense.cpp
@@ -8,6 +8,32 @@
  */
 
 #include "cdm_ion_sense.h"
+#include "engine.h"
+
+CdmState::CdmState() {
+	currentRevolution = 0;
+	currentValue = 0;
+	accumulator = 0;
+}
+
+int CdmState::getValue() {
+	return currentValue;
+}
+
+void CdmState::onNewSignal(int currentRevolution) {
+	if (this->currentRevolution == currentRevolution) {
+		accumulator++;
+	} else {
+		this->currentRevolution = currentRevolution;
+		currentValue = accumulator;
+		accumulator = 1;
+	}
+}
+
+#if EFI_CDM_INTEGRATION
+#include "digital_input_exti.h"
+
+EXTERN_ENGINE;
 
 #if EFI_TUNER_STUDIO
 void ionPostState(TunerStudioOutputChannels *tsOutputChannels) {
@@ -15,4 +41,34 @@ void ionPostState(TunerStudioOutputChannels *tsOutputChannels) {
 }
 #endif
 
+static CdmState instance;
 
+
+static void extIonCallback(EXTDriver *extp, expchannel_t channel) {
+        UNUSED(extp);
+
+        int currentRevolution = engine->triggerCentral.triggerState.getTotalRevolutionCounter();
+
+        instance.onNewSignal(currentRevolution);
+
+}
+
+
+void cdmIonInit(void) {
+	// todo: allow 'GPIOA_0' once we migrate to new mandatory configuration
+	if (boardConfiguration->cdmInputPin == GPIOA_0 || boardConfiguration->cdmInputPin == GPIO_UNASSIGNED) {
+		return;
+	}
+	int pin = (int)boardConfiguration->cdmInputPin;
+	if (pin <= 0 || pin > (int)GPIO_UNASSIGNED) {
+		// todo: remove this protection once we migrate to new mandatory configuration
+		return;
+	}
+
+
+	enableExti(boardConfiguration->cdmInputPin, EXT_CH_MODE_RISING_EDGE, extIonCallback);
+
+}
+
+
+#endif /* EFI_CDM_INTEGRATION */
diff --git a/firmware/hw_layer/cdm_ion_sense.h b/firmware/hw_layer/cdm_ion_sense.h
index fd62fcbf49..71022a0ee5 100644
--- a/firmware/hw_layer/cdm_ion_sense.h
+++ b/firmware/hw_layer/cdm_ion_sense.h
@@ -10,9 +10,27 @@
 
 #include "global.h"
 
+class CdmState {
+public:
+	CdmState();
+	int currentRevolution;
+	/**
+	 * accumulated value for engine cycle which is not over yet
+	 */
+	int accumulator;
+	/**
+	 * event counter for previous complete engine cycle
+	 */
+	int currentValue;
+	void onNewSignal(int currentRevolution);
+	int getValue();
+};
+
 #if EFI_TUNER_STUDIO
 #include "tunerstudio_configuration.h"
 void ionPostState(TunerStudioOutputChannels *tsOutputChannels);
 #endif
 
+void cdmIonInit(void);
+
 #endif /* HW_LAYER_CDM_ION_SENSE_H_ */
diff --git a/firmware/hw_layer/hardware.cpp b/firmware/hw_layer/hardware.cpp
index 2e66cdb077..9c57f806d9 100644
--- a/firmware/hw_layer/hardware.cpp
+++ b/firmware/hw_layer/hardware.cpp
@@ -42,6 +42,7 @@
 #include "settings.h"
 #include "algo.h"
 #include "joystick.h"
+#include "cdm_ion_sense.h"
 #include "trigger_central.h"
 #include "svnversion.h"
 #include "engine_configuration.h"
@@ -490,6 +491,10 @@ void initHardware(Logging *l) {
 	initVehicleSpeed(sharedLogger);
 #endif
 
+#if EFI_CDM_INTEGRATION
+	cdmIonInit();
+#endif
+
 #if HAL_USE_EXT || defined(__DOXYGEN__)
 	initJoystick(sharedLogger);
 #endif
diff --git a/simulator/simulator/efifeatures.h b/simulator/simulator/efifeatures.h
index 01e158a2a6..17b9703a9a 100644
--- a/simulator/simulator/efifeatures.h
+++ b/simulator/simulator/efifeatures.h
@@ -14,6 +14,8 @@
 
 #define EFI_PRINTF_FUEL_DETAILS TRUE
 
+#define EFI_CDM_INTEGRATION FALSE
+
 #define EFI_BLUETOOTH_SETUP FALSE
 
 #define EFI_GPIO_HARDWARE FALSE
diff --git a/unit_tests/test.mk b/unit_tests/test.mk
index c702d9a823..7da51abf62 100644
--- a/unit_tests/test.mk
+++ b/unit_tests/test.mk
@@ -5,6 +5,7 @@ TEST_SRC_CPP = test_util.cpp \
 	test_basic_math/test_find_index.cpp \
 	test_basic_math/test_interpolation_3d.cpp \
 	test_cj125.cpp \
+	test_ion.cpp \
 	test_hip9011.cpp \
 	test_data_structures/test_engine_math.cpp \
 	test_startOfCrankingPrimingPulse.cpp \
diff --git a/unit_tests/test_c125.h b/unit_tests/test_c125.h
deleted file mode 100644
index a7712c5abb..0000000000
--- a/unit_tests/test_c125.h
+++ /dev/null
@@ -1,11 +0,0 @@
-/*
- * test_c125.h
- *
- *  Created on: Jan 3, 2019
- * @author Andrey Belomutskiy, (c) 2012-2019
- */
-
-#ifndef TEST_C125_H_
-#define TEST_C125_H_
-
-#endif /* TEST_C125_H_ */
diff --git a/unit_tests/test_cj125.cpp b/unit_tests/test_cj125.cpp
index b0f2b6c740..0c11835d4f 100644
--- a/unit_tests/test_cj125.cpp
+++ b/unit_tests/test_cj125.cpp
@@ -5,7 +5,6 @@
  * @author Andrey Belomutskiy, (c) 2012-2019
  */
 
-#include "test_c125.h"
 #include "gtest/gtest.h"
 
 TEST(testCJ125, todo) {
diff --git a/unit_tests/test_ion.cpp b/unit_tests/test_ion.cpp
new file mode 100644
index 0000000000..9858f199a2
--- /dev/null
+++ b/unit_tests/test_ion.cpp
@@ -0,0 +1,34 @@
+/*
+ * test_ion.cpp
+ *
+ *  Created on: Jan 4, 2019
+ *      Author: user
+ */
+
+#ifndef TEST_ION_CPP_
+#define TEST_ION_CPP_
+
+#include "gtest/gtest.h"
+#include "cdm_ion_sense.h"
+
+TEST(ion, signalCounter) {
+	CdmState state;
+
+	EXPECT_EQ(0, state.getValue());
+
+	state.onNewSignal(2);
+	state.onNewSignal(2);
+	state.onNewSignal(2);
+
+	// value is still '0' until we signal end of engine cycle
+	EXPECT_EQ(0, state.getValue());
+
+	// this signals start of new cycle
+	state.onNewSignal(4);
+	EXPECT_EQ(3, state.getValue());
+
+
+}
+
+
+#endif /* TEST_ION_CPP_ */