As the project description emphasizes, this SAO is kind of ridiculous.

I'll be the first to admit that the feature list above grew a bit out of hand. The SAO has ended up closer to a badge than it has to any other SAO I've ever designed (I guess the main thing missing is a SAO port? 🤔). 

You could argue, and you'd probably be right, that the only things really needed on this SAO are the four capacitive touch pads, and possibly the i2s amplifier. The badge could do the rest. But in my opinion "the SAO" (as a concept) is at its strongest when you can give it away to someone, they can plug it in, and it will start doing its thing. 

I mean: their badge firmware is already busy doing other things, the person receiving the SAO is already busy being at a hacker-con, and they might soon swap your SAO out for another one. Especially if it requires *work* to make it interesting.

For this reason, most of my SAOs (yeah, this is my 7th or 8th since last years SuperCon - depending on how you count) doesn't do much other than blinking an LED or two. Some of them will not even blink the LEDs, just light them. This way I can keep the cost at a minimum and personally assemble them in large enough volumes that I can hand them out like candy.

At SuperCon 2023 I brought around 30 SAOs of a single design, and I quickly felt like that was too little. At Hackaday Europe earlier this year, I increased my stock - but also the number of different designs I brought. At some point during the evening I realized I could look around me and see one of my SAOs in almost every group of people located around me. I thought that was really cool and that's why, when Hackaday announced their 2024 SAO design contest, I felt it was right up my alley. After all, designing SAOs is the main hobby activity I've been doing over the last 12 months.

However, "there's a catch!", as the official contest page phrases it.

Traditionally SAOs have been all about the look, PCB art and blinking LEDs. This year, we want to change that. We’re challenging makers and hackers to build functional SAOs, or as we’ve come to call them, Supercon Add-Ons.

The designs I've been making over the last year have been superhero designs, to which I obviously don't own the copyright - even though I did the actual artwork myself (with comics as reference). In other words: they are not eligible to the contest. Even if they were, they don't respond to this call-to-action.

So I was forced to come up with something completely different if I wanted to participate in the contest. And I did! But I wanted to stay as close to my original philosophy of handing out cheap working SAOs as possible. That being said, I allowed myself to break the rules about cost and assembling a lot of them by myself if it became necessary. After all, the prize of the contest is that someone else will pay for, and assemble, the design - so who cares, right?

I've been curious about capacitive touch for a while, and been on the lookout for a project where I could get more familiar with them, so this contest was the perfect opportunity to dive deep and learn how to design (and use) those.