Flip-Dot Bus Display Converted to Voice-Controlled, Multi-Function Clock

Electromechanical flip-dot displays are amazing devices, showing data with an array of magnetic dots that flip into place as needed. Now largely replaced by LCD screens and the like, people have been recycling them for other purposes — often as clocks. Hacker “caesiumhydroxid,” however, decided to take things to the next level, creating a flip-dot clock display that can also play games and show the weather. This former Lawo bus display even reveals departures of nearby tram and bus stops via the Vienna Open Data API. So things have apparently come full circle.

The build is powered by a Raspberry Pi 4, along with a custom driver board and an ATmega8 microcontroller. Time is set via NTP (Network Time Protocol) and it automatically adjusts for daylight savings, so there’s no reason to fiddle with it. The units features voice recognition capabilities via Snips as well, and has a light sensor to turn off when it’s dark. While the flip dots don’t produce light themselves, the sound can be pretty loud, so you wouldn't want this going when you’re trying to sleep.

As yet another feature, the clock runs Pi Hole to block ads. After all, if you have a Pi running a relatively “low brainpower” task at all times, why not have it take care of something else too?

You can see the device in action in the video below, demonstrating its ability to show the time and weather, as well as play Snake and Pong via virtual smartphone control pads. Also notable is the sturdy wooden enclosure that holds the build together.