The circuit cube bluetooth kit with it's tiny motors keeps spreading within the AFOL train community (e.g. see this review or this wonderful model). I see two drawbacks with the current version of the official app: only one module can be connected it needs some kind of (expensive) smart device So I asked Tenka (the manufacturer of these kits) for details about the protocol. They kindly shared the documentation and so I started implementing a "bluetooth hub". Using the information from the legoino project my program connects to one LEGO Powered Up remote and up to two circuit cube modules. It runs on a tiny Computer ("M5 Atom") which measures 3x3 studs. So you still need an additional device, but this is tiny and inexpensive and can be placed somewhere on the layout - or even built into the trains. In the videos this is the small grey box connected to the USB power supply. In one mode you can control the official kit: as long as the buttons of the remote are pressed the motors spin with the maximum velocity:   The other mode is useful for trains: when a button is pressed the velocities of all motors connected to the corresponding module are increased/decreased: This is currently a "proof-of-concept" - the source code is available in github but using it will require some (basic) knowledge about programming Arduino-like devices.