ARM Powered® MindCuber solves Void Cube

Build your own Rubik's Cube® solver from just a LEGO® MINDSTORMS® NXT 2.0 set.

ARM has previously demonstrated a variety of ARM Powered® robots constructed from smartphones and LEGO MINDSTORMS solving a variety of Rubik's Cube style puzzles including the world-famous CubeStormer II created by Mike Dobson and David Gilday.

These robots show the range of performance and presence of energy-efficient ARM processors from small, embedded microcontrollers to high performance application and graphics processors which are present in consumer products.

ARM fully endorses STEM (Science, Technology, Engineering and Mathematics) education and adoption. David Gilday, the creator of these robots, decided to try to use his robot activities to inspire young (and "not so young"!) minds to take an interest and develop skills in these areas, while having fun at the same time.

David's latest robot, "MindCuber" was designed specifically with the aim of sharing its design freely for others to try out, enjoy and hopefully increase their passion for mechanics, engineering, math and problem-solving skills along the way.

MindCuber is carefully designed so that it can be constructed from only the pieces available in a standard LEGO MINDSTORMS NXT 2.0 kit to make it accessible to as many people as possible. Unlike David's previous designs. MindCuber can solve a standard 3x3x3 Rubik's Cube without the aid of a smartphone, camera or other external device.

David is thrilled that recently the LEGO Group published instructions for MindCuber on their LEGO MINDSTORMS website so now anybody can build their own! ☺

This video shows MindCuber solving a Void Cube which is slightly more complex than a standard 3x3x3 Rubik's Cube since the missing center pieces allow some combinations of positions to be reached that would apparently not be reachable on a regular cube.

The software for the solver runs on the ARM7™ microprocessor in the NXT "Intelligent Brick" using the LEGO color light sensor to scan the cube. The ultrasonic sensor is used to detect when the cube is inserted to start the solve automatically. MindCuber uses a table-driven solving algorithm that was developed to fit in the limited memory of the NXT while generating reasonably short solutions of around 30 to 40 moves.

The total solve time, including the scan, averages around 1 min 55 sec's, making it probably the fastest robot Rubik's Cube solver ever built entirely from LEGO bricks.

MindCuber's unique mechanical design allows the cube to be manipulated quickly and reliably using only two motors allowing the third motor to be used to move the color sensor during the scan.

[IAssemble]

Thanks. If you just put the default colours, matching the void cube's colors, in the centers, there can be a "parity" issue (similar to cubes with an even number of pieces per side that also have no piece at the center of each face) that means the standard algorithm cannot always solve the cube like this. But there is something you can do to avoid having to change the actual solving algorithm (I leave this as a challenge for you to think about) :-)

[ProjectXe]

Very nice. Never seen the void cube before. Does it even effect the algorithm? I mean you can just use default colors for the center of each side. But maybe I'm completly wrong there ^^

[IAssemble]

Thanks for letting me know. I'm glad it helped. Does your MindCuber work completely now? Are you going to post a video of it solving the cube? :-)

[IAssemble]

I am not going to release the program for the Void Cube version as I hope that when the source code is available for MindCuber with the Rubik's Cube solving algorithm that people will be inspired to try to adapt it for themselves! :-)

[cachetgal]

Cool video of the MindCuber solving the Void Cube, but then I am biased as my husband built it!

[IAssemble]

MindCuber does not need any mechanical change to solve the Void Cube shown in this video. So the build instructions on the LEGO MINDSTORMS web site are sufficient. It can be achieved with only a software change - that is your challenge! ;-)

[ZCubing]

Is it able to predict in which spot it should put the centers so it doesn't get parity at the end? Or does it just deal with the parity if it gets it?

[IAssemble]

@WilliamStemNetwork thanks for asking for the program for the Void Cube solver. Please see my response to @BManCan1's related question for the answer.

[BManCan]

@DavidGilday Does the published MindCuber program solve the Void Cube, or did you have to customize the program? Thanks.

[shaunbrennan]

I would tip my hat to you sir (but I don't have one on right now)

[fish]

yes that was the problem thanks for your time it is working now

[IAssemble]

The source code for the original MindCuber software will be shared on the mindcuber web site (see link at the end of the description)

[WilliamStemNetwork]

can you give the program for the void cube solver

[WilliamStemNetwork]

do you think its possible to do it with the curved void cube?, not the square one

[matokliment]

where can I get program for void cube?