Monthly Archives: May 2020

Conways Game of Life

Finished up the hardware to display the results of my coding exercise. My primary goal was to learn a little more about python and object oriented coding. I could never really wrap my head round objects, and I needed a project with real end goals to address that. The code is available and has documentation on github.

Basic construction is comprised of 16×16 pixel ws2812 panels in a 3×3 grid. The way the panels were laid out and wired made a sort of weird numbering scheme, which I had to compensate for in software. Next time i’d be more planful on which inputs go to which outputs.

I made a picture frame out of walnut to contain the insides. There are actually 2 panes of glass with the following layers:
(front)
Glass
Matte with display window cut
Glass
Papyrus type paper for led diffusion
The 3d-printed grid
the wooden panel with the led’s mounted
(back)
This stack keeps everything tight/contained and keeps the LED grid close agains the diffuser paper so the lines are crisp. I used the LED grid so i’d get colored squares instead of circles, to me it really looked a LOT better.

The somewhat ungainly back of the stack. I put air holes along the top as I wasn’t sure. how much heat the LED’s would generate, but they aren’t running at full brightness and the glass doesn’t even get warm to the touch. You’ll notice the 3 cross braces, which are bowed up by spacers in the middle. This presses the whole grid tightly against the glass, keeping the lines displayed bye the grid on front tight. Powered by a raspberry pi with a small level converter IC to talk 3.3v -> 5v.

Pandemic Clock

What day is it anyway? Seems like that is the running joke working from home these days. With a fair amount of idle time on my hands I thought I’d make a little clock to help out. One of the construction goals was to use parts on hand, as going out to stores wasn’t really in the cards.

Clock face is some pretty basic plywood i had on hand, with the days pocketed in with the CNC machine. I did use a 1/8″ downcut bit to not chip-out the super thin layer of good wood on the top. Next time I do something like this I’d cut through tape as it would make the next epoxy-filling step a lot easier.

The text is a 2-part 30 minute epoxy with some coloring mixed in. My son has gotten pretty good at mixing/pouring. Did our best to clean up any spillage with mineral spirits while it was still wet, and later sanded what was left with a 320grit paper. The movement is just a small hobby servo, but it only rotates about 160 degrees. I 3d printed out two gears to create a 2:1 ratio so the servo could swing pretty much the full 360 degrees to move the hands. For gear generation I used gearDXF.

The controller is a NodeMCU, which is an esp8266 dev board. These are programmed with the Arduino IDE, and controlling a servo is easy with the built in library.

Code is on github if you are interested. Here is a link to the fusion model.