His device works by converting accelerometer analog outputs into digital signals via 3×4 comparators, 6 are used for the X-axis and 6 for the Y-axis. From then on discrete logic chips are used to convert the different signals into various positions on a 8×8 dot matrix LED display. Since the dot matrix display only allows for one row of LEDs to be on at one time, he used a demultiplexer that cycles trough the rows in succession while maintaining persistence of vision for the user.
He made his schematic available, as well as lots of information and theory about its function. Check out the video of the device in action below.
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