diff --git a/software/main.py b/software/main.py
index 7dfd0a8..6258901 100644
--- a/software/main.py
+++ b/software/main.py
@@ -24,6 +24,8 @@ class ModuleButton(QPushButton):
         self.form.ui.lblTitle.setText(self.mod.title)
         self.form.ui.areaModule.setWidget(self.mod.widget)
         self.form.ui.areaModule.show()
+        self.form.mod = self.mod
+        self.mod.start()
 
 class Main(QMainWindow):
     def __init__(self):
@@ -40,6 +42,7 @@ class Main(QMainWindow):
 
     @pyqtSlot()
     def on_btnBack_clicked(self):
+        self.mod.stop()
         self.ui.lblTitle.setText('EduBRM')
         # TODO: erase everything from self.ui.areaModule
         self.ui.areaChoose.show()
diff --git a/software/modules/ModuleA.py b/software/modules/ModuleA.py
index da31c89..84665df 100644
--- a/software/modules/ModuleA.py
+++ b/software/modules/ModuleA.py
@@ -4,5 +4,8 @@ class ModuleA():
         self.title = 'A'
         self.widget = None
 
-    def run(self):
-        print 'run A'
+    def start(self):
+        print 'start A'
+
+    def stop(self):
+        print 'stop A'
diff --git a/software/modules/ModuleDebug.py b/software/modules/ModuleDebug.py
index d260483..2942156 100644
--- a/software/modules/ModuleDebug.py
+++ b/software/modules/ModuleDebug.py
@@ -151,5 +151,9 @@ class ModuleDebug():
         self.title = 'Debug'
         self.widget = ModuleDebugWidget()
 
-    def run(self):
-        print 'run Debug'
+    def start(self):
+        print 'start Debug'
+
+    def stop(self):
+        print 'stop Debug'
+        self.widget.timer.stop()