The OPEN-CUBE project

Around 2009, an introductory and motivational course for students of the Cybernetics and Robotics study program was launched here at the Faculty of Electrical Engineering of the Czech Technical University in Prague. Over the years, LEGO Mindstorms NXT and EV3 sets have been used to build extraordinary robots. But lately these sets have become obsolete, hard to buy, after years of use at the end of life and the new alternative “Spike” has not met our expectations…

So we decided to develop an alternative – an open-source control unit, compatible with NXT and EV3 sensors and motors (as well as mechanical LEGO parts). After more than a year of development and several prototypes build, we present the first “production version” that works nicely and supports some extra tricks that the previous versions didn’t have. And is completely open-source.

Learning through play

that’s the right way 🙂
OPEN-CUBE a Glance

Micropython. We use C-code directly embedded in the Micropython package, so the mission critical tasks are done fast and the user can enjoy coding in Micropython using specific framework functions. Sorry, no graphical programming right now.


The development of Open-Cube started in 2021, when there were still serious problems with the purchase of some electrical components (eg microcontrollers), so the design is based on two devices that were very readily available – a Raspberry RP2040 microcontroller (PICO) and an ESP32 module. Both are also very cheap. Hopefully they will be available for some time to come. If not, the Open-Cube electrical circuits are fairly simple, so they can be easily modified or updated.

Open-Source Design

All production data and firmware including source codes are available for download. Free for non-commercial use. If you want to use the provided data commercially, please contact us.

Developed in

Ing. David Novotný – HW
Bc. Václav Jelínek – FW, SW, tester
Bc. Jakub Vaněk – FW guru, SW, tester
Ing. Michal Dressler – 3D print wizard
Ing. Vojtěch Petrucha, Ph.D. – HW, FW, management…
and other (e.g. team project students)

The Open-Cube development was supported by the Faculty of Electrical Engineering, CTU in Prague, via RPAPS projects in 2022 and 2023.

Production of the first series proudly sponsored by – R&D with NO LIMITS!