BricKuber – Rubik's Cube Solver

Watch It in Action

Background

The Rubik's cube — invented in 1974 and the world's best-selling toy — requires thought, skill, and plenty of patience. So why not let a robot do it?

The BricKuber combines a Raspberry Pi, BrickPi3, and LEGO Mindstorms to build a fully automated Rubik's cube solver. Place an unsolved cube in the cradle, run the Python program, and watch as the robot scans each face, computes the optimal solution, and executes every move in under two minutes.

This project is inspired by the MindCub3r design for LEGO EV3, extended to use the Raspberry Pi Camera instead of the EV3 Color Sensor.

Tools & Materials

• BrickPi3 (Core or Starter Kit)
• Raspberry Pi (Pi 3 or newer)
• Raspberry Pi Camera Module
• LEGO Mindstorms EV3 Kit (31313) — includes 2 large motors & 1 medium motor
• A standard 3×3 Rubik's Cube (any freely-spinning cube works)
• microSD card (≥ 8 GB) with Raspberry Pi OS Trixie for BrickPi3
• 12 V battery pack for BrickPi3
• Ethernet cable or Wi-Fi dongle (internet connection needed for initial setup)

Build It

Step 1 – Build the Base Structure

Start with the MindCub3r design. Full LEGO building instructions are available at mindcuber.com. The BricKuber has three major moving parts:

• Cube cradle — holds and rotates the Rubik's cube
• Shuffler arm — flips the cube onto a different axis
• Camera arm — positions the Raspberry Pi Camera above the cube

Step 2 – Assemble the BrickPi3

Follow the BrickPi3 assembly guide to put together the case. Attach the BrickPi3 board, Raspberry Pi, and the Pi Camera ribbon cable. Use the LEGO EV3 "wings" to support the BrickPi3 and keep it level with the BricKuber body.

Step 3 – Connect the Motors

• Shuffler motor → Motor Port D
• Cradle motor → Motor Port A
• Camera arm motor → Motor Port C

Step 4 – Attach the Camera

Secure the Pi Camera between the two LEGO beam supports on the camera arm. Use a small strip of electrical tape to hold it in place. Verify the camera can see the entire top face of the cube:

raspistill -o cam.jpg

Open cam.jpg and confirm the cube is well-centred in the frame. Adjust the camera position and focus before continuing.

Software Setup

Install the BrickPi3 libraries

If you're using Raspberry Pi OS Trixie for BrickPi3 the libraries are already installed. Otherwise, run:

sudo curl -kL dexterindustries.com/update_brickpi3 | bash

Install BricKuber dependencies

sudo curl https://raw.githubusercontent.com/DexterInd/BrickPi3/master/Projects/BricKuber/install_brickuber.sh | bash

The installer pulls in three key Python libraries:

• rubiks-cube-tracker — converts a photo of a cube face into nine RGB values
• rubiks-color-resolver — maps 54 RGB values to the six unique face colours
• kociemba — computes an efficient solution using the Kociemba two-phase algorithm

Solving a Cube

Place an unsolved Rubik's cube in the cradle and run:

sudo python ~/Dexter/BrickPi3/Projects/BricKuber/BricKuber.py

The robot will rotate the cube to each of the six faces, take a photo of each, determine the configuration, calculate the solution, and then execute every move automatically.

Source Code

All source code is open on GitHub:

• github.com/DexterInd/BrickPi3 – Projects/BricKuber