For the past few years we’ve been dealing with buttons.  Moving, storing, sorting, picking through, and generally managing a large collection of castaway buttons from a previous company.  Some were usable, but many lacked the micro-switch that gives the button any functionality at all.  Why do I mention this?  Because having these buttons made us try and think of ways of getting rid of them using them for fun projects!

One of the ideas that we came up with was a very simple one. Put as many buttons on the wall as possible and let people press them. Of course, it’d be better if they lit up and responded. Without any particular game in mind though, we knew that people will love these things. Fact: people love to press buttons. So, we started construction on a few “Button Walls.”


The general design is simple: put the buttons on the wall, use a microcontroller to monitor them and make them light up. However, there are always complications, including some we create ourselves. In an effort to use as few parts as possible, we use multiplexors to light up the LEDs and monitor the button switches. Wiring all of the buttons takes quite a bit of patience. (Special thanks to Eliot for helping us out and making these pretty!)


Of course, we made this version a pair of fun gears. (A quick nod to Matthias Wandel for his gear generating software!)


And if you build a couple of interlocking gears, they absolutely must turn. Unfortunately, this isn’t negotiable. But, how do we get these gears to turn and not tangle up the wires? Well, wireless works wonders in getting the signal to a server so these button walls can interact. But power is more difficult. Some of the installations for these things are permanent, so we better come up with a better solution.


The answer, of course, is a slip ring. These slip rings were available from Adafruit.


We mounted it to a wooden board, which connected the gears to the lazy susan bearing we picked up from VXB Bearings. The end result is a pair of interlocking gears that can rotate easily. You’ll notice that the gears are a little bit separated so we don’t have to clean up as much spilled blood when people inevitably put their hands in there.


Here’s a video of it in action: