It really looks best in person. :/ (Tried to get to look like it would in person though.)
video here: youtu.be/N_53snzOqOQ
Spent a little long fiddling with the brightness, so you can see the minute change twice.
I initially built this incandescent matrix more-so for a single digit clock, but I figured two just made too much sense to pass up. I used my Protean 8x2 as the controller board, which you can buy on Tindie: www.tindie.com/stores/adamlhum…
(I’ll be adding a new product soon, a bare PCB called QuickTiny for those super simple projects where you just want something small to take care of the boilerplate stuff within a small footprint.)
Notice the hour is offset form the minutes to easily tell them apart.
It uses an old laptop 18.5V power supply with 9.84V bulbs, (#0947).
Rather than messing with an IR library, despite committing a few improvements to one on GitHub, I used one of those “5V IR Infrared Remote Decoder Encoding Transmitter Receiver Wireless Module DIY” on eBay. Simple serial, though it tops out at 57,600 baud. Still pretty convenient. Only good for the common NEC protocol though, but that’s fine.
For the PPS, or pulse per second, I used an ATtiny44 SOIC I already had on a board with a 32.768kHz watch crystal. It’s overkill, but I can always throw in something cheaper later.
I might make this a scrolling clock later, but next time, (if there is a next time), I’d make each digit separate and with a fixed colon like a classic digital clock. I also plan on having another font choice as well.