@musthafa : look on the MySensors forum for the MYSController, install it and you can monitor the messages going to the gateway.
Most likely your declaration of the LED output pin on the MySensors arduino is not correct. I still did not use arduinos as actuators with MySensors so I will probably not be of much help here.
In OpenHAB it worked as a dimmer. Later on OpenHAB was stuck and my mobile app was frozen. Then I start discovering Domoticz. If it can be discovered in OH2 why not in Domoticz ?