An eBay Addiction, a Logic Analyzer, and a VR Game: How I Made Some Christmas Decorations Dance

Adam Leventhal
8 min readDec 30, 2019

This was kind of a silly project. If I had known it would end with a bunch of wholesome Christmas decorations dancing along to Lizzo I probably would have done it a long time ago. Here’s the story of how I took some beloved kitsch, a logic analyzer, sed, awk, Google Sheets, Python, an FT232H, some wires, data from a VR game, and a few evenings to make it happen. (Just want the punchline? Skip to the end.)

Happy Tapper eBay addiction

My family has a fair bit of music-producing stuff from Hallmark: books, stuffed animals, and, of course, holiday decorations. Chalk it up to an enthusiastic grandparent. The Happy Tappers are a favorite. We started with two — a reindeer and a snowman — and I was tasked with filling out the full set of four. We now have 13, so mission accomplished and then some.

Some debate in my family about whose toys these are…

Each Tapper plays two songs and dances; you can plug in other Tappers via ports on either side and they become backup dancers. Deeply alluring, clearly. I got a good deal on Santa, then a better deal on a different Santa. Then there was a great deal on a set of 4, so had to get it. Then — after months of waiting — I pounced on a set of 5, including the very rare “painter” elf. So, in short: I have a problem. This solstice holiday season my plan was to figure out how they work and get them to do some out-of-spec dancing.


My first step was to pull one apart. There’s a microcontroller (covered with scratched up epoxy) that controls the speaker and electromagnet actuators while sending and receiving signals over the bus formed by connecting multiple Tappers (henceforth, the Dance Bus).

Adam Leventhal

Building computers at Oxide; past: DTrace, ZFS, Delphix CTO, Transposit founder, CEO