Ben Combee's Simplest SAO Gives Your Badge a New, Compact Color Button Display
Built using two off-the-shelf boards and a little dab of hot glue, this very simple Simple Add-On adds a video-capable display.
Software engineer Ben Combee has created a Simple Add-On (SAO) badge accessory that gives a badge a compact, circular, color display — using only off-the-shelf parts and a little hot glue.
"When I heard about Hackaday Supercon 8's emphasis on Simple Add-Ons, I decided to wanted to turn my badge hack from 2023 into something I could mount on this year's badge," Combee explains, referring to a project from last year which played back video files on the badge's built-in circular display. "Lots of people had noticed that the core hardware in the 2023 VectorScope badge was similar to a board that Waveshare sells, and I'd bought a few of those after the con to port my code onto."
The release of a smaller 0.99" circular display by hobbyist electronics specialist Waveshare gave Combee the idea to relaunch the project, this time not targeting a specific badge but instead creating a Simple Add-On (SAO) accessory, which could, in theory, be connected to any compatible badge to add a new display.
"I'd originally wanted to make my own PCB, but while looking at other hardware, I found that Adafruit stocks an AVR ISP [In-System Programming] connector on a breakout board for under $1 that exactly matches the add-on side of the SAO standard," Combee recalls. "The pin labels aren't the same, but once you wire it up, who's looking at the board anymore?"
Using the two, plus some hot-glue to keep the pair mated, Combee found it possible to turn the display into the simplest possible SAO — happily playing back video on both the Vectorscope and Voya4 badges. It's even possible to address the Waveshare board's built-in inertial measurement unit (IMU) — though, Combee notes, not at the same time as addressing the display.
The project is documented in full, with wiring diagram, on Hackaday.io.