Around these parts, projects needlessly using a microcontroller where a simpler design would do are often derided with the catch-all “Should have used a 555,” even if the venerable timer chip wouldn’t have been the ideal solution. But the sentiment stands that a solution more complicated than it needs to be is probably one that needs rethinking, as this completely mechanical chaser light badge Simple Add-On (SAO) aptly demonstrates.

Rather than choosing any number of circuits to turn a strip of discrete lights on and off, [Johannes] took inspiration for his chaser lights from factory automation mechanisms that move parts between levels on steps that move out of phase with each other, similar to the marble-raising mechanism used in [Wintergatan]’s Marble Machine X.

Two thin plates with notches around the edge are sandwiched together inside the 3D printed case of the SAO, between the face and the light source. A small motor and a series of gears rotate the two masks 180° out of phase with each other, which creates the illusion that the light is moving.

It’s pretty convincing; when we first saw the video below, we were sure it was a row of tiny LEDs around the edge of the badge.

Hats off to [Johannes] for coming up with such a clever mechanism and getting it working just in time for Hackaday Europe. If you need to catch up on the talks, we’ve got a playlist ready for you.

We just got back from Hackaday Europe last weekend, and we’re still coming down off the high. It was great to be surrounded by so many crazy, bright, and crazy-bright folks all sharing what they are pouring their creative energy into. The talks were great, and the discussions and impromptu collaborations have added dramatically to our stack of to-do projects. (Thanks?) Badges were hacked, stories were shared, and a good time was had by all.

At the event, we were approached by someone who wanted to know if we could replicate something like Hackaday Europe in a different location, one where there just isn’t as vibrant a hacking scene. And the answer, of course, was maybe, but probably not.

It’s not that we don’t try to put on a good show, bring along fun schwag, and schedule up a nice location. But it’s the crowd of people who attend who make a Hackaday event a Hackaday event. Without you all, it just wouldn’t work.

So in that spirit, thanks to everyone who attended, and who brought along their passions and projects! It was great to see you all, and we’ll do it again soon.

Hackaday Europe 2025 is in full swing, and whether you’re experiencing it live in Berlin or following along from home, here’s where you’ll find all the info you need to get the most out of it.

Event Page: https://hackaday.io/europe2025

Chat: Hackaday Discord (Channels: europe-2025 / badge-hacking)

Talk Streams: https://www.youtube.com/@hackaday/streams

Hackaday Europe 2025 is just days away, and we’ve got the finalized speaker schedule hot off the digital press. We’re also pleased to announce that the event page is now officially live, where you can find all the vital information about the weekend’s festivities in one place.

Whether you’ll be joining the fun in Berlin, or watching the live stream from home, we’ve got a fantastic lineup of speakers this year who are eager to tell us all about the projects that have been keeping them up at night recently:

Saturday Schedule

Time Has Run Out!

Tickets sold out a few days ago, so if you’ve got one we’ll see you soon, and if not, we will be streaming all of the Saturday talks live, so hit up Hackaday on the weekend and you can play along, at least virtually. And for back-channel chat, join us on the Hackaday Discord #europe-2025 channel.