Word clocks are great fun. They basically show the time using full words – “TWELVE TWENTY ONE AM,” for example – and they often come in larger sizes. But what about one that is about as big as a Pokemon card.
This DIY device uses multiple LEDs, a 3D printed case, and a little bit of code. From the project page:
A main concern when I first started this project was that there would be too much light bleed between nearby letters, thus making the display difficult to read for lack of contrast. To help on the pcb side, I opted for black soldermask, and additionally used the copper layer to try and block as much light as possible, but none of these would help with light scattered internally in the pcb’s FR4 material which is a yellowish semi-opaque hue that works pretty well as a diffuser. I’ve gotten tons of suggestions involving using vias around each letter to try and contain as much light as possible within each letter, but I really liked how clean the top surface looked without having to riddle it with vias.
So the main method I could fall back on was the age old method of using a physical separator between each LED to try and contain as much of the light as possible. Luckily I have a 3D printer and was able to very quickly print out a few test prints to iterate a light box design which also doubles as a stand for the clock, holding it up at a slight angle.
If you have the time and wherewithal it might be a fun weekend project.