The Bob-clock

NOTE: This page is being updated.

This it the Bob-clock project page. Here you will find information about how the Bob-clock works, how to build the hardware and use the code, and the history of the project.

The Bob-clock is now available as a kit from the Lumisense web shop. Information about the kit will be posted on, and the assembly inctructions are available on the Lumisense Wiki.

On this page I will present the project, describe the hardware and fimware, and the optional parts that can be added to a Bob-clock. I will also mention a few ideas that have not yet been implemented.

I have decided to split this into several pages, to give a better overview of the project:

What is the Bob-clock?

the Bob-clock

The Bob-clock is a wall-clock which uses 60 multi-colored LEDs arranged in a circle to represent the small and big arm of an analog clock. If desired, it can also display the seconds with a third color. The image above shows the Bob-clock (v2.0 hardware, but v2.1 and v2.2 looks the same from the front).

On this version, the blue light signifies the hour-hand, while the red one is the minutes, so in this image the time is about 10 minutes to 4. When both the minute and hour arms are in the same position, the colors will be mixed. Mixing blue and red results in a purple/magenta color.

For the first Bob-clocks (the v1.0 version that my uncle Bob got, and after whom the clock is named, as well as the v2.0 clocks I built), the face plate is hand-made from aluminum, which was sanded down and coated with matte lacquer, giving it a nice brushed aluminum look.

Last updated: 2011.11.16