To create the wall I used a 22″x28″ poster board that I cut down to 22″x23″. I created a graphic of the wallpaper and alphabet, and broke it up in to six ledger size (11″x17″) pages. I recommend using a glue stick to attach the printouts to the poster board. I used glue from a squirt bottle, but that wet the paper too much and made it wrinkle, which is not so bad because it gave the wallpaper an aged look.
To attach the WS2811 LED Christmas lights to the alphabet wall I used hot glue. This doesn’t work the best though because the silicone cover around the LEDs can become unstuck from the hot glue. I believe wrapping some black ribbon around the silicone covers would make them stick to the hot glue much better.
A nylon belt was attached to the board so I could hang it around my neck. The microcontroller board and battery pack are held in a pencil box attached to the back of the board.
Electronics and Code
For the controller I used a Teensy 2.0 at 5V. I installed the Teensyduino add-on for Arduino so I could run Arduino sketches on the board. Using a Teensy specifically isn’t a requirement; it’s just what I had on hand. My sketch has several modes that can be cycled through by pressing a push button. One of the modes allows custom strings to be written by using a smart phone with a serial terminal installed and a USB OTG cable. The video demonstrates the Stranger Things themed mode.