Entry 1: How It Started

A project log for Building a Conference Badge: LIWho 2023

A Tamagotchi-style game-playing badge with a scavenger hunt and AI-driven interactive fiction... how much more 2023 could it be?

jorj-bauerJorj Bauer 08/10/2023 at 13:490 Comments

I started small. Really, I did.

My 40% scale Special Weapons Dalek is, as its name says, smaller than it could be. It was my "Gateway Dalek" in to the world of prop building ("It'll make you feel good") and lead to a full-sized (Well, 94%, so it clears doorways) Imperial Dalek named Geo. So I've got a pile of Dalek guts, parts, molds, cabinets for transportation, spraypaints, screws, washers, fiberglass chemicals, etc., which eventually meant I needed to buy an actual trailer to house and transport all of it.

I might have a problem.

Way too much spraypaint

So when the bug caught me in late 2019 to do something new, I had to think hard about where I'd build it and how I'd store it. The only sane conclusions (not that sanity is really a prerequisite here) were (a) don't, because there's no space left; (b) buy a new house, because this one is full; or (c) find a way to not store it when I'm done.

Obviously (a) isn't going to happen. It's not in my genes. I tried playing video games, watching TV, and generally doing nothing for a year after knee surgery and found that, not surprisingly, I don't like it. And (b) is right out; we love our not-too-huge somewhat-overcrowded house, and as we'll be empty nesters in the near future it should kinda come back to being the right size for us in our continuing middle aged years. Besides, I'd wind up on the hook for spending more time cleaning a bigger house - obviously time I could be using better by just cluttering up whatever space we've got.

So how does one make something for a convention and then not have anything physical to show for it after the fact? It would have to be something to give away. With some kind of continued use. And this is where I started thinking about electronic conference badges.

In early 2020, I designed a quick prototype and sent it off to It mostly resembles the final product:

First prototype badge

Designed with a card edge connector in mind (lots of recent work on my Apple //e had me thinking about them), but not having bought an actual card edge socket yet, you can see I've got wires soldered to the pads on the back. 12 LEDs in a charlieplex arrangement, 6 through-hole buttons, 4 current-limiting resistors, an ATTiny84a to run them (I had some of them sitting around the house already) and I was hooked. This had to happen.

There were, of course, some issues.

The pads on the back were a source of noise, if your hands held the pads in "just the right way". (The dock protocol was just serial and it would occasionally engage while you were playing a game.) I went through a couple different prototype layouts - moving the serial to the front of the board, for example - and was never really happy with it.

But the biggie was that I ran out of program space on the '84a. I switched from the Arduino IDE to a gcc toolchain, and I quickly ate that up too. When I started thinking about re-coding the whole thing in assembly, I put the project down and focused on pandemic life instead. There weren't any conventions coming up any time soon, and I had built a proof of concept that really resonated with me. Now it was just a matter of time.