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What is an SAO?

SAO stands for Simple Add-On. It's a small PCB that plugs into a host badge through a standardized 2x3 pin header, originally created for DEF CON's badge ecosystem and now used at many conferences.

What an SAO does

An SAO can be as simple as a piece of PCB art with a couple of LEDs, or as complex as a full microcontroller-based mini-badge with sensors, displays, or its own logic. The standard pinout provides:

  • 3.3V power
  • Ground
  • I²C SDA / SCL for communication with the host
  • Two general-purpose I/O pins

Why people collect them

SAOs are wearable, swappable, and tradeable. At hardware-friendly conferences, you'll see attendees walking around with a host badge full of SAOs from other crews — each one a little piece of someone else's design.

We've designed several SAOs over the years. A few are still available on our Tindie store, and others were one-off runs handed out at specific events.

SAOs we've made

  • SAO_BadgePirates — our logo SAO
  • SAO_HankPropane — a Hank Hill tribute
  • SAO_Holder-Sword — the 2022 sword totem holder
  • SAO_keanu-homeboy — well... it's Keanu

A more complete list is in our GitHub organization under any repo starting with SAO_.

Want to make your own?

The SAO standard is open and well documented. Our Common Library on GitHub has KiCAD footprints you can drop into your own design.