Ben Wasserman's 3D-Printable Modular SAO Wall Tile Puts Your Badge's Simple Add-Ons on Display

Developer and maker Ben Wasserman has, like many badge enthusiasts, a hefty collection of Simple Add-Ons (SAOs) — but rather than letting them languish in a desk drawer has designed a modular mounting system that lets them go on display, fully powered up.

"I collected too many SAOs (over 20) at Supercon last year, and I want to display them properly," Wasserman explains. "I'm inspired by the SAO Wall at Supercon, but it's too big for my home and I want something more modular so I can fit it in various locations and expand as needed. I also didn't want to deal with batteries (replacing real ones, or permanently powering fake ones), so I wanted external power."

The Simple-Add On (SAO) standard, formerly known by a less family-friendly name, specifies a simple interface between electronic badges and their accessory PCBs. As increasing numbers of events opt to release a badge design, it's become common for exhibitors and attendees to design accessories for trade — and, as Wasserman found, also common to end up coming home from such an event with pockets bulging.

The display system Wasserman has designed is based on 3D-printed hexagonal mounts — "hexagons are bestagons," he explains, "and tile nicely with themselves" — with a central PCB offering four SAO ports each. There's a USB Type-C connector for power, and pads to mount a Raspberry Pi Pico W or Raspberry Pi Pico 2 W microcontroller development board to give the system connectivity and controllability. If you need to display more SAOs than a single hexagonal tile can host, you can chain power between multiple mounts.

"I'm hoping the design is flexible enough that people can make upgrades that are backwards compatible and there can be variants of the design that can be used together," Wasserman says. "I want others to be able to also display their SAOs at home, and I hope this can make that easier. I work primarily in software, so this was a fun electrical and mechanical design and manufacturing challenge."

The project is documented in full on Hackaday.io, with KiCad project files and FreeCAD frame design with 3D-printable STLs on GitHub under an unspecified license.