Hacks & BuildsRaspberry Pivolumetric displaysDIY
Vortex spins a Raspberry Pi and two LED panels into a playable 3D globe
AncientJames shares printable mechanical parts and a desktop simulator for an unusually physical fantasy console. Balancing the assembly remains part of the job.
The Raspberry Pi goes around with the screen. Vortex puts a little computer and two LED panels in a spinning assembly, then times the light to the rotation. Your desktop has acquired a spin cycle, and the laundry is a tesseract.
Maker AncientJames publishes the Multivox software that drives it and the mechanical parts that hold it together. This is the maker’s account of the build, including its limitations. The hardware assumptions are wonderfully specific: two HUB75 panels, a vertical axis, and a single GPIO signal that stays high for half a revolution and low for the other half.
That signal gives the software a rotational reference. The driver reads a three-dimensional buffer in shared memory and scans the appropriate contents onto the panels as they turn. Client programs fill that buffer with the objects to display. Both halves run on the embedded Raspberry Pi 4, which the README says spins at several hundred RPM along with the hardware. A screen saver has rarely required this much literal saving of the screen.
Vortex uses two 128-by-64 panels arranged horizontally, back to back, inside its 300 mm sphere. The related Rotovox uses a larger 400 mm orb and a different panel arrangement. The maker describes a trade: Rotovox has greater vertical resolution and horizontal density; Vortex favors brightness and refresh rate. The choice changes how much vertical detail a model can retain and how brightly it appears in the orb.
Play the video on YouTubeThe included toys make that buffer useful immediately. There are multiplayer light cycles, a model viewer, fireworks and a tesseract demo. A Bluetooth gamepad supplies input, with the maker using an Xbox controller. Multivox presents the programs as cartridges, and an exiting app leaves a snapshot of its volume for a launcher preview. The README calls this an “alternate timeline Vectrex,” with the cartridges represented inside the same volume their games will use.
The software also exposes the compromises. Increasing color depth reduces refresh rate. Other controls adjust brightness uniformity, rotation locking and the handling of skipped voxels. A brighter image, a steadier image and a richer palette compete for the same time. The spinning panels can only visit so many places before another revolution begins.
The parts list adds a car-alternator slip ring, bearings, carbon-fiber rods and a motor. Its sphere began as a post-top lamp. The maker warns that the design used components already on hand, and the control-dial discussion says builders will spend considerable time balancing it. The fancy dial uses an accelerometer to help with that balancing work (naturally, more electronics), while the alternate dial is a speed controller and knob.
That leaves a useful route for anyone tempted to reproduce the effect. The simulator can test content and alternate geometries before a motor enters the conversation. A successful animation there still leaves the physical assembly, balance and synchronization to solve. Future variants could keep the same content interface while changing the geometry, provided their driver can map that buffer onto the moving panels.
The lamp now has a gamepad.