White board beats chalk board, LED marquee beats white board, and an LED white board trumps them all.
This hybrid lets you draw on the surface with dry erase markers while Conway’s game of life plays out underneath. [Bert] sent us this tip after seeing yesterday’s office marquee. This version is quite similar in appearance but the guts are very different. Inside you’ll find a Parallax SX28 microcontroller doing the heavy lifting. The display is multiplexed but they didn’t go with a common 595 shift register, but a beefier MAX6979 LED driver. We’re not too familiar with this part but it does have a lot of nice features like constant current, and automatic shutdown if serial data stalls for more than 1 second. This is a low-side driver so transistors are used to connect voltage to the rows; the opposite from the setup we looked at yesterday. This was built several years ago and is still working happily even though its permanent home is a breadboard. Source code can be found on this page.
This board is up at UAT if anyone is interested. The parallax is also open (underneath the dry erase markers in the picture).
@Charon
as of 2pm eastern, the webcams on that website show 2 uber nerds play magic or whatever card game it is… lol.
Blackboard is superior to whiteboard any day of the year!
@alan
Yeah… UAT is full of nerds, and like max 10 girls. None of us get any, so we all go for the next best thing, Magic…
It’s always fun to get a surprise mention on Hackaday! Thanks Bert. Since it looks like you can remember more of the circuit than I have over the last few years, you should draw up the schematic for us.
BTW, hand soldered LEDs, solid wire and hot glue made it all come together… not so much fun but I’d do it again in a heartbeat.
@Sean:
I don’t think I remember much more than you. That write-up has been up on my site for a while now, just never thought of submitting it!
Indeed, it was a long project, cutting wires, soldering, hot glueing and getting the connectors soldered right as well as the code, hats off to you still for that piece of magic!