“The mechanics are constructed entirely from LEGO, including four MINDSTORMS NXT kits, with the addition of a Samsung Galaxy S II smartphone running a custom Android app as the robot’s brain. Both the MINDSTORMS NXT kits and the Samsung Galaxy SII use a variety of ARM –based processors.
The app uses the phone’s camera to capture images of each face of the Rubik’s Cube which it processes to determine the scrambled colours. The solution is found using an advanced two-phase algorithm, originally developed for Speedcuber, enhanced to be multi-threaded to make effective use of the smartphone’s dual-core ARM Cortex-A9 1.2GHz processor. The software finds an efficient solution to the puzzle which is optimised specifically for the capabilities of the four-grip mechanism. The app communicates via Bluetooth with software running on the ARM microprocessors in the LEGO NXT Intelligent Bricks which controls the motors driving the robot. During the physical solve, the app uses OpenGL ES on the phone’s ARM Mali-400 MP GPU to display a graphical version of the cube being solved in real time.”