diff --git a/src/app/buttoneventslogger.cpp b/src/app/buttoneventslogger.cpp
index c6d92c3..0ec8c3f 100644
--- a/src/app/buttoneventslogger.cpp
+++ b/src/app/buttoneventslogger.cpp
@@ -12,9 +12,9 @@
 ButtonEventsLogger::ButtonEventsLogger()
 	: stWait(this) {
 
-	stInitial.setNextState(&stWait);
-	stWait.setNextState(event::evButtonShortPressed, &stWait);
-	stWait.setNextState(event::evButtonLongPressed, &stWait);
+	stInitial.addInitialTransition(&stWait);
+	stWait.addTransition(event::evButtonShortPressed, &stWait);
+	stWait.addTransition(event::evButtonLongPressed, &stWait);
 	stWait.registerOnEntry((XFState::callbackEv)&ButtonEventsLogger::logOnTrace);
 }
 
diff --git a/src/mdw/button/ButtonEventsHandler.cpp b/src/mdw/button/ButtonEventsHandler.cpp
index 47ca17a..6bdede2 100644
--- a/src/mdw/button/ButtonEventsHandler.cpp
+++ b/src/mdw/button/ButtonEventsHandler.cpp
@@ -16,7 +16,7 @@ ButtonEventsHandler::ButtonEventsHandler()
 		observer_[i] = nullptr;
 	}
 
-	stInitial.setNextState(&stRun);
+	stInitial.addInitialTransition(&stRun);
 	stRun.registerOnEntry((XFState::callback)&ButtonEventsHandler::startButtonSM);
 
 }
diff --git a/src/mdw/button/ButtonStateSm.cpp b/src/mdw/button/ButtonStateSm.cpp
index e190eb7..20a5564 100644
--- a/src/mdw/button/ButtonStateSm.cpp
+++ b/src/mdw/button/ButtonStateSm.cpp
@@ -8,10 +8,27 @@
 #include <button/ButtonStateSm.h>
 #include "mdw/button/ButtonEventsHandler.h"
 
-//TODO start State Machine. For that, turn ButtonEventsHandler to a State Machine (Initial, run)
 ButtonStateSm::ButtonStateSm()
-	: buttonIndex_(getNbInstance()) {
-	currentState_ = state::initial;
+	: buttonIndex_(getNbInstance()),
+	  stWaitButtonPressed(this),
+	  stButtonPressed(this),
+	  stButtonShortPressed(this),
+	  stButtonLongPressed(this) {
+
+	stInitial.addInitialTransition(&stWaitButtonPressed);
+
+	stWaitButtonPressed.addTransition(event::evButtonPressed, &stButtonPressed);
+
+	// TODO bug if setTimeout is used before addTransition !!!
+	stButtonPressed.addTransition(event::evButtonReleased, &stButtonShortPressed);
+	stButtonPressed.setTimeout(1000, &stButtonLongPressed);
+	stButtonPressed.registerOnExit((XFState::callback)&ButtonStateSm::genNullTransition);
+
+	stButtonShortPressed.registerOnEntry((XFState::callback)&ButtonStateSm::notifyShortPress);
+	stButtonShortPressed.addTransition(event::evReturn, &stWaitButtonPressed);
+
+	stButtonLongPressed.registerOnEntry((XFState::callback)&ButtonStateSm::notifyLongPress);
+	stButtonLongPressed.addTransition(event::evReturn, &stWaitButtonPressed);
 }
 
 uint8_t ButtonStateSm::getNbInstance(){
@@ -26,102 +43,14 @@ void ButtonStateSm::genButtonReleased() {
 	GEN(XFEvent(XFEvent::Event, event::evButtonReleased, this));
 }
 
-XFEventStatus ButtonStateSm::processEvent() {
-	eEventStatus eventStatus = XFEventStatus::Unknown;
-
-	const XFEvent* ev = getCurrentEvent();
-	XFEvent::XFEventType evType = ev->getEventType();
-	int evid = ev->getId();
-
-	oldState_ = currentState_;
-	changeState_ = false;
-
-	switch (currentState_) {
-		case state::initial:
-			if(evType == XFEvent::Initial) {
-				currentState_ = state::waitButtonPressed;
-				changeState_ = true;
-				eventStatus = XFEventStatus::Consumed;
-			}
-			break;
-
-		case state::waitButtonPressed:
-			if(evid == event::evButtonPressed) {
-				currentState_ = state::buttonPressed;
-				changeState_ = true;
-				eventStatus = XFEventStatus::Consumed;
-				scheduleTimeout(event::evTimeout, 1000);
-			}
-			break;
-
-		case state::buttonPressed:
-			if(evid == event::evButtonReleased) {
-				currentState_ = state::buttonShortPressed;
-				changeState_ = true;
-				eventStatus = XFEventStatus::Consumed;
-				unscheduleTimeout(event::evTimeout);
-			}
-			if(evid == event::evTimeout) {
-				currentState_ = state::buttonLongPressed;
-				changeState_ = true;
-				eventStatus = XFEventStatus::Consumed;
-			}
-			GEN(XFNullTransition(this));
-			break;
-
-		case state::buttonShortPressed:
-			if(evType == XFEvent::XFEventType::NullTransition) {
-				currentState_ = state::waitButtonPressed;
-				changeState_ = true;
-				eventStatus = XFEventStatus::Consumed;
-			}
-			break;
-
-		case state::buttonLongPressed:
-			if(evType == XFEvent::XFEventType::NullTransition) {
-				currentState_ = state::waitButtonPressed;
-				changeState_ = true;
-				eventStatus = XFEventStatus::Consumed;
-			}
-			break;
-	}
-
-	if(changeState_) {
-		switch (oldState_) { // onExit
-			case state::initial:
-				break;
-
-			case state::waitButtonPressed:
-				break;
-
-			case state::buttonPressed:
-				break;
-
-			case state::buttonShortPressed:
-				break;
-
-			case state::buttonLongPressed:
-				break;
-		}
-
-		switch (currentState_) {
-			case state::initial:
-				break;
-
-			case state::waitButtonPressed:
-				break;
-
-			case state::buttonPressed:
-				break;
-
-			case state::buttonShortPressed:
-				ButtonEventsHandler::getInstance()->notifyButtonShortPressed(buttonIndex_);
-				break;
-
-			case state::buttonLongPressed:
-				ButtonEventsHandler::getInstance()->notifyButtonLongPressed(buttonIndex_);
-				break;
-		}
-	}
-	return eventStatus;
+void ButtonStateSm::notifyShortPress() {
+	ButtonEventsHandler::getInstance()->notifyButtonShortPressed(buttonIndex_);
+}
+
+void ButtonStateSm::notifyLongPress() {
+	ButtonEventsHandler::getInstance()->notifyButtonLongPressed(buttonIndex_);
+}
+
+void ButtonStateSm::genNullTransition() {
+	GEN(XFEvent(XFEvent::Event, event::evReturn, this));
 }
diff --git a/src/mdw/button/ButtonStateSm.h b/src/mdw/button/ButtonStateSm.h
index 72f2d85..3b8111a 100644
--- a/src/mdw/button/ButtonStateSm.h
+++ b/src/mdw/button/ButtonStateSm.h
@@ -18,27 +18,24 @@ public:
 	void genButtonReleased();
 
 protected:
-	XFEventStatus processEvent();
+	void notifyShortPress();
+	void notifyLongPress();
+	void genNullTransition();
 
 	typedef enum {
-		evButtonPressed,
+		evButtonPressed = 10,
 		evButtonReleased,
-		evTimeout
+		evTimeout,
+		evReturn
 	} event;
 
-	typedef enum {
-		initial,
-		waitButtonPressed,
-		buttonPressed,
-		buttonShortPressed,
-		buttonLongPressed
-	} state;
-
-	state currentState_;
-	state oldState_;
-	bool changeState_;
 	const uint8_t buttonIndex_;
 
+	XFState stWaitButtonPressed;
+	XFState stButtonPressed;
+	XFState stButtonShortPressed;
+	XFState stButtonLongPressed;
+
 private:
 	static uint8_t getNbInstance();
 
diff --git a/src/platform/f7-disco-gcc/board/ButtonsController.cpp b/src/platform/f7-disco-gcc/board/ButtonsController.cpp
index d6e822c..a67a55c 100644
--- a/src/platform/f7-disco-gcc/board/ButtonsController.cpp
+++ b/src/platform/f7-disco-gcc/board/ButtonsController.cpp
@@ -16,8 +16,8 @@ ButtonsController::ButtonsController()
 	cbProvider = nullptr;
 	cbMethod = nullptr;
 
-	stInitial.setNextState(&stCheckButtons);
-	stCheckButtons.setNextState(event::evButtonIrq, &stDebounce);
+	stInitial.addInitialTransition(&stCheckButtons);
+	stCheckButtons.addTransition(event::evButtonIrq, &stDebounce);
 	stCheckButtons.registerOnEntry((XFState::callback)&ButtonsController::fctCheckButtons);
 
 	stDebounce.setTimeout(20, &stCheckButtons);
diff --git a/src/xf/core/XFState.cpp b/src/xf/core/XFState.cpp
index 3b22dd3..ed88adb 100644
--- a/src/xf/core/XFState.cpp
+++ b/src/xf/core/XFState.cpp
@@ -14,9 +14,15 @@
 XFState::XFState(XFBehavior* behavior)
 	: pBehavior(behavior) {
 	assert(behavior != nullptr);
+	cbState_ = nullptr;
+	cbEntry_ = nullptr;
+	cbExit_ = nullptr;
+	cbEvState_ = nullptr;
+	cbEvEntry_ = nullptr;
+	cbEvExit_ = nullptr;
 }
 
-void XFState::setNextState(const int evid, const int time, XFEvent::XFEventType type, XFState* state) {
+void XFState::addTransition(XFEvent::XFEventType type, const int evid, const int time, XFState* state) {
 	assert(state != nullptr);
 	transition t;
 	t.evid = evid;
@@ -28,9 +34,6 @@ void XFState::setNextState(const int evid, const int time, XFEvent::XFEventType
 
 XFEventStatus XFState::onState(const XFEvent* ev) {
 
-	assert(ev != nullptr);
-	assert(pBehavior != nullptr);
-
 	if(cbState_ != nullptr) {
 		(pBehavior->*cbState_)();
 	}
@@ -39,7 +42,6 @@ XFEventStatus XFState::onState(const XFEvent* ev) {
 	}
 
 	for(transition t : transitions_) {
-		assert(t.nextState != nullptr);
 
 		if(t.evType == XFEvent::XFEventType::Initial){
 			pBehavior->curentXFState_ = t.nextState;
@@ -68,12 +70,12 @@ void XFState::onEntry(const XFEvent* ev) {
 	if(cbEntry_ != nullptr) {
 		(pBehavior->*cbEntry_)();
 	}
+
 	if(cbEvEntry_ != nullptr) {
 		(pBehavior->*cbEvEntry_)(ev);
 	}
 
 	for(transition t : transitions_) {
-		assert(t.nextState != nullptr);
 
 		if(t.evType == XFEvent::XFEventType::Timeout) {
 			pBehavior->scheduleTimeout(XFEvent::Timeout, t.time);
@@ -85,7 +87,17 @@ void XFState::onExit(const XFEvent* ev) {
 	if(cbExit_ != nullptr) {
 		(pBehavior->*cbExit_)();
 	}
+
 	if(cbEvExit_ != nullptr) {
 		(pBehavior->*cbEvExit_)(ev);
 	}
+
+	for(transition t: transitions_) {
+
+		if(t.evType == XFEvent::XFEventType::Timeout) {
+			if(ev->getEventType() != XFEvent::XFEventType::Timeout) {
+				pBehavior->unscheduleTimeout(XFEvent::Timeout);
+			}
+		}
+	}
 }
diff --git a/src/xf/include/xf/XFState.h b/src/xf/include/xf/XFState.h
index 695d0f4..7f527d6 100644
--- a/src/xf/include/xf/XFState.h
+++ b/src/xf/include/xf/XFState.h
@@ -24,10 +24,9 @@ public:
 	XFState(XFBehavior* behavior);
 	~XFState() = default;
 
-	inline void setNextState(XFState* state) { setNextState(XFEvent::Initial, XFEvent::XFEventType::Initial, state); };
-	inline void setNextState(const int evid, XFState* state) { setNextState(evid, XFEvent::XFEventType::Event, state); };
+	inline void addTransition(const int evid, XFState* state) { addTransition(XFEvent::XFEventType::Event, evid, 0, state); };
 
-	inline void setTimeout(int time, XFState* nextState) { setNextState(XFEvent::Timeout, time, XFEvent::XFEventType::Timeout, nextState); };
+	inline void setTimeout(int time, XFState* nextState) { addTransition(XFEvent::XFEventType::Timeout, XFEvent::Timeout, time, nextState); };
 	typedef void (XFBehavior::*callback)();
 	typedef void (XFBehavior::*callbackEv)(const XFEvent* ev);
 	//inline void registerOnState(callback cbState) { cbState_ = cbState; };
@@ -38,8 +37,7 @@ public:
 	inline void registerOnExit(callbackEv cbExit) { cbEvExit_ = cbExit; };
 
 protected:
-	inline void setNextState(const int evid, XFEvent::XFEventType type, XFState* state) {setNextState(evid, 0, type, state); };
-	void setNextState(const int evid, const int time, XFEvent::XFEventType type, XFState* state);
+	void addTransition(XFEvent::XFEventType type, const int evid, const int time, XFState* state);
 
 	XFEventStatus onState(const XFEvent* ev);
 	void onEntry(const XFEvent* ev);
@@ -55,13 +53,20 @@ protected:
 	} transition;
 	std::list<transition> transitions_;
 
-	callback cbState_ = nullptr;
-	callback cbEntry_ = nullptr;
-	callback cbExit_ = nullptr;
-	callbackEv cbEvState_ = nullptr;
-	callbackEv cbEvEntry_ = nullptr;
-	callbackEv cbEvExit_ = nullptr;
+	callback cbState_;
+	callback cbEntry_;
+	callback cbExit_;
+	callbackEv cbEvState_;
+	callbackEv cbEvEntry_;
+	callbackEv cbEvExit_;
 
 };
 
+
+class XFInitialState : public XFState {
+public:
+	inline XFInitialState(XFBehavior* behavior) : XFState(behavior) {};
+	~XFInitialState() = default;
+	inline void addInitialTransition(XFState* state) { addTransition(XFEvent::XFEventType::Initial, XFEvent::Initial, 0, state); };
+};
 #endif /* XFSTATE_H_ */
diff --git a/src/xf/include/xf/behavior.h b/src/xf/include/xf/behavior.h
index 725ba23..1ff1826 100644
--- a/src/xf/include/xf/behavior.h
+++ b/src/xf/include/xf/behavior.h
@@ -100,7 +100,7 @@ protected:
     const XFEvent * pCurrentEvent_;					///< Reference to actually processed event.
 
 protected:
-    XFState stInitial;
+    XFInitialState stInitial;
 	XFState* curentXFState_ = &stInitial;
 	XFState* oldXFState_ = &stInitial;
 	bool changeXFState = false;