When you walk into the Science and Engienering Complex (SEC) at Harvard, you will be greated by a magnificient display: The Harvard Time capsule.
The time capsule is an interactive installation by the Art Group BREAKFAST, based on flip disc technology. It is attached to depth sensor cameras that allow the users to interact with the real-time changing display. The display “remembers” all past interactions and replays them - so no interaction is ever forgotten.
A flip disc, or flip dot, display, is an electromagnetic dot matrix display. Unlike LED, it functions by flipping the dots using magnetism. The dots themselves do not light up, it’s only their fast flipping through magnets that generates a stunning effect. That also carries the advantage that they use far less power than LED displays. The technology is/was commonly used for displays on buses or at airports.
BREAKFAST has been developing flip disc displays for a while now, and host a great variety of past projects on their website. My favorite is their Antarctic Ice:
Unfortunately, their installations are quite expensive. Generally, it’s difficult to get hands on a flip disc display. I found the company AlfaZeta that sells flip disc displays, but they both small, unicolored, and in the price range of $200-500 as well. Therefore, I want to build one myself!
First, I started reading a bit more on flip disc displays and the underlying technology on Wikipedia:
Then, I delved into a the few DIY projects and tutorials around flip disc displays that I could find. Most were based on buying and using an existing flip disc display, and then controlling them through a microcontroller. However, I did find some that explained the technology and how to build it in more detail.
Larry even published the CAD files for his 3D printed flip disc display on Github!