1U WOPR

Concept

A while ago I came across this great idea from Printables user @aforsberg_1223867 and immediately set out to build it. All the credit for the concept behind this goes to them. 😄

However, I had a number of problems with the model, printability and it didn't ultimately fit my rack. After some mods with a drill, I got it installed and then it broke.

So I went and did the whole thing from scratch, including pulling other rack designs I've done and measuring all parts fresh. No part of the original author's model was used in this other than the concept of the lights center aligned in 1U. This is designed for easy printing with no supports, easy assembly and self-alignment, and strength. It also uses standard rack hole spacing and slot dimensions and will work with rack nuts and bolts, or most alternative rack mounting mechanisms.

Once I got the hardware up and running, I also went back and watched clips from the movie and wanted more of the original design elements from the theatrical WOPR in the animations, so I ended up entirely rewriting the software portion as well. It still uses a Raspberry Pi Pico, wired the same way, with MicroPython, however the software is now async for multiple different animations running simultaneously. All the code is hosted on Github.

I hope you enjoy this and it build well. And please be sure to check out the original model linked above, it really is a super cool idea 😄

Animations

The screen is broken down into 5 columns with columns 2 and 4 split upper and lower. These each have a different animation on them:

• 8x8 - Fixed seed animation shifting left/right
• 16x4 - Fixed seed animation randomly splitting in half shifting left/right
• 16x2 - 32-bit "program counter" with random re-seed
• 32x8 - Conway's Game of Life with random seed and stall detection to re-seed
• 16x4 - Fixed seed like before with different rules and speed
• 16x2 - Randomized 32-bit count down with random re-seed
• 16x8 - The original author's animation algo

Note: these are subject to change with the code, check out the linked repo for the latest.

Print Settings and Assembly

I recommend printing this in PETG with 4 wall loops and 20% Gyroid infill. I used little squeeze clamps to hold the 4 joints together, using a flat surface to ensure no bowing, letting the self-aligning geometry do the rest. One-by-one, I would release a clamp, squeeze in some CA gel and squeeze it back shut, hit it with some activator and count to 10. Repeat for each of the other three joints and it's ready for the lights.

I soldered the three modules together but in hindsight could have bent the pins up and used jumpers. Then placed the assembly into the frame and used hot glue in a few places to hold them all fast. If I need to remove it, I can use isopropyl alcohol to loosen the clue and pry it out. The Pi Pico is Capton taped in place behind it… this is an area of improvement for the model, to have solid mounting points for the electronics.

After that, plug in the Pi, upload the code and you should be good to rack it up!