Here are a few screenshots of my current setup. The custom cards for the virtual keypad and group status are available for download in the download section.

Home Assistant interface
MQTT Autodiscovery
Screenshot of the web interface
Galaxy Gateway web interface
Galaxy Gateway profile view
Galaxy Gateway Profile view
Galaxy Gateway top view
Galaxy Gateway Font view
Galaxy Gateway back view
Galaxy Gateway Back view
KNX-TP board prototype
KNX-TP board prototype