diff --git a/tikka/slots/pyqt/windows/main.py b/tikka/slots/pyqt/windows/main.py
index 7f10cd96cf8b13c9511b702846ac82cf2467cdc4..7f873a2aacf336bbe2aeda05085f2067225161e4 100644
--- a/tikka/slots/pyqt/windows/main.py
+++ b/tikka/slots/pyqt/windows/main.py
@@ -12,6 +12,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import logging
 import sys
 from typing import TYPE_CHECKING, Any, List, Optional
 
@@ -506,6 +507,7 @@ class MainWindow(QMainWindow, Ui_MainWindow):
 
         :return:
         """
+        logging.debug("create instance of ScanQRCodeWindow")
         ScanQRCodeWindow(self.application, self).exec_()
 
     def open_add_address_window(self) -> None:
diff --git a/tikka/slots/pyqt/windows/scan_qr_code.py b/tikka/slots/pyqt/windows/scan_qr_code.py
index f30643362fcdb117cacf36f0be8799f5d1c0ce7c..88e1dfbb00fbbabb3a52862062740f3016a29611 100644
--- a/tikka/slots/pyqt/windows/scan_qr_code.py
+++ b/tikka/slots/pyqt/windows/scan_qr_code.py
@@ -12,6 +12,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import logging
 import sys
 from typing import List, Optional
 
@@ -65,16 +66,21 @@ class QRCodeVideoSurface(QAbstractVideoSurface):
         self.video_label = video_label
 
         # initialize the OpenCV QRCode detector
+        logging.debug(
+            "Create OpenVC qrcode detector instance with cv2.QRCodeDetector()"
+        )
         self.detector = cv2.QRCodeDetector()
 
     def supportedPixelFormats(
         self, type: QAbstractVideoBuffer.HandleType = QAbstractVideoBuffer.NoHandle
     ) -> List[QVideoFrame.PixelFormat]:
         result = []
+        logging.debug("supportedPixelFormats Type = %s", type)
         if type == QtMultimedia.QAbstractVideoBuffer.NoHandle:
-            result = [
-                QtMultimedia.QVideoFrame.Format_RGB32,
-            ]
+            logging.debug(
+                "supportedPixelFormats returns QtMultimedia.QVideoFrame.Format_RGB24"
+            )
+            result = [QtMultimedia.QVideoFrame.Format_RGB24]
 
         return result
 
@@ -178,19 +184,26 @@ class ScanQRCodeWindow(QDialog, Ui_ScanQRCodeDialog):
         self.addressValueLabel.setFont(monospace_font)
 
         # fill form
-        if self.check_camera_availability() is False:
+        camera_available = self.check_camera_availability()
+        if camera_available is False:
             self.errorLabel.setText(self._("No camera available"))
         else:
+            logging.debug("Create instance of QCamera()")
             self.camera = QCamera()
+            logging.debug("Create instance of QRCodeVideoSurface()")
             self.video_surface = QRCodeVideoSurface(self.videoLabel)
+            logging.debug(
+                "set VideoSurface instance as camera viewfinder with camera.setViewfinder(self.video_surface)"
+            )
             self.camera.setViewfinder(self.video_surface)
+            logging.debug("Start camera with camera.start()")
             self.camera.start()
 
         # buttons
         self.buttonBox.button(self.buttonBox.Ok).setEnabled(False)
 
         # events
-        if self.check_camera_availability() is True:
+        if camera_available is True:
             self.video_surface.detected.connect(self.qrcode_detected)
         self.buttonBox.accepted.connect(self.on_accepted_button)
         self.buttonBox.rejected.connect(self.close)
@@ -202,6 +215,7 @@ class ScanQRCodeWindow(QDialog, Ui_ScanQRCodeDialog):
 
         :return:
         """
+        logging.debug("Check if there is a webcam : QCameraInfo.availableCameras()")
         return len(QCameraInfo.availableCameras()) > 0
 
     def qrcode_detected(self, data: str):
@@ -246,6 +260,7 @@ class ScanQRCodeWindow(QDialog, Ui_ScanQRCodeDialog):
 
 
 if __name__ == "__main__":
+    logging.basicConfig(level=logging.DEBUG)
     qapp = QApplication(sys.argv)
     application_ = Application(DATA_PATH)
     ScanQRCodeWindow(application_).exec_()