Shitty Robot Holiday Card Display
Over the winter holidays, Simone Giertz made holiday cards using a KUKA robot arm (Or maybe a KUKA robot arm made holiday cards using Simone Giertz?). Regardless, I received one of these wonderful cards by supporting her on Patreon. This is no mere piece of paper so I created an equally shitty display stand using 3D printing and a microcontroller with a multicolored LED backlight.
My first design was only a plastic stand to test my dimensions. Of course, it printed perfectly. I decided it was too boring, so I hacked it up and added some electronics inside to control the backlighting. It uses an Arduino Pro Mini and a WS2812 RGB LED Module (also known as a NeoPixel Stick) plus a USB connector to supply 5V power. I’m using a completely unmodified strantest.ino file for the soothing rainbow pattern. Check out this guide if you want to install the software and libraries yourself. The connections are very simple: I’m powering the Arduino and NeoPixels from the USB port (ensure you’re using the right pins — I messed up here it took me a while to figure out why it wasn’t working reliably). The NeoPixel’s datain line is connected to Arduino pin D6. Many guides suggest connecting it differently, but this worked for me, so I kept it. If you run into issues, do some research on the “correct” way to power them.
I liked having the LEDs light the paper from behind, but my first design didn’t light up the whole card evenly. I designed a new hollow shell with a hole in the back for the USB connector. Unfortunately, this print gave me a ton of issues. My 3D printer driver software kept freezing on my Mac (from an unfixed bug reported 6 years ago), so I had to hand modify the G-code to continue the print where it stopped on my PC. I believe this hand off is (at least partially) the cause of the failure in the middle of the print. Initially, I only planned to test this print for the correct dimensions, but then I decided that a gift from the Queen of Shitty Robots really deserved a shitty print to show it off.
Some of my dimensions were off, but I was able to fix them with a knife. All of the source files are available on Thingiverse — use them at your own risk. I mounted the Arduino and LEDs inside with hot glue and made sure to tuck the wires to the rear so they wouldn’t create shadows. The LEDs point up from the bottom and help to evenly illuminate the card.
I had fun making this and now that it’s complete, I’m thinking of ideas to improve it. It might be fun as a music visualizer. Instead of constantly cycling through colors, it would only be lit up when I’m in the room playing music. One of my first electronics projects was a music visualizer, so I’d love to see how I can improve that design.
Thanks for stopping by! If you have any suggestions for improvements or need assistance making one for yourself, feel free to contact me on Twitter: @Dillon1337
