An open source LED grid clock
So your analog wall clock breaks… What do you do about it? Make a digital clock, of course. Lumitock is an “LED grid” clock, where the time is represented by the number of lit LEDs within a segment of the clock.
Lumitock is based on the Arduino platform, specifically using an Arduino Pro Mini 328 (socketed, I have commitment issues). It also uses a DS1337C RTC for time-keeping, and TLC5940 LED drivers to keep track of all that light. I used BatchPCB (now OSH Park) to fab some boards for it, and they turned out great. Very solid, and such an easy service when time isn’t much of a factor.
It is open hardware and software, available on github. The Arduino project as well as Eagle CAD project files are included.
Beware! The current version (tag version-1) has a fairly nasty issue with the PCB layout, the TLC5940 sockets were drawn as .4″ wide, not .3″. Not fun to solder that up, you can see the kludgey fixes in the images.
TODO Embed: https://youtu.be/MHyRmk73WY8