Maker Zach Jon Butler has launched a design for a Raspberry Pi RP2040-powered volumetric show system, which works by spinning a 16×16 RGB LED matrix at excessive pace — together with all of the electronics driving it.
“I used to be impressed by [a] video from a YouTuber known as Mitxela,” Butler writes of the mission’s origins, referring to a rotary persistence of imaginative and prescient show constructed and showcased by maker Tim Alex Jacobs again in December 2023. Like Jacobs’ design, Butler’s creation depends on the human eye’s tendency to “smear” rapidly-moving shiny lights to show a 2D matrix of LEDs right into a 3D picture — making a 3D volumetric show Butler colloquially refers to as an RGB “hologram.”
Butler’s tackle the idea is cut up into two elements. The primary is the LED matrix itself, a 16×16 array of tiny surface-mount RGB LEDs on a compact PCB with an edge connector designed to mechanically mate with a PCI Specific socket — although carrying no PCI Specific alerts. This hyperlinks it to a round mainboard that hosts no fewer than 4 Raspberry Pi RP2040 dual-core microcontrollers: one to drive a P-channel high-side field-effect transistor (FET) to modify the columns and three as present sinks on the rows.
A motor beneath the board spins all the pieces — RGB matrix and driver board — at excessive pace, inflicting a persistence of imaginative and prescient impact that turns the 2D matrix right into a 3D picture. With the best code, that 3D picture will be handled as a real, although low-resolution, 3D volumetric show — as has been demonstrated to spectacular impact with James Brown’s ongoing work within the space.
“I believe it would want actually excessive frequency updates to replace the pixels on the proper spot in the course of the spin,” Butler explains of the rationale for giving the system no fewer than eight Arm Cortex-M0+ microcontroller cores throughout 4 discrete chips. “There [are] 16×16×3 [768 total] LEDs to manage and I would like the spin to occur at a minimum of 24 rotations per second.”
Butler has launched design recordsdata for the LED matrix board and the motive force base board on OSHWLab underneath a public area license, with code a work-in-progress on the time of writing; extra data is offered in his Reddit publish.
