When Stranger Things came out all those years ago, one image left an indelible mark on pop culture. A set of Christmas lights, lined up with letters of the alphabet, such that the kid who was barely in the show could blink out messages at Winona Rider from Topsy Turvy Town. [MyEmbeddedStuff] has recreated this cross-dimensional communication system for a fun Halloween project.
The build is basically a Xiao ESP32-S3 microcontroller board and a string of WS2812B addressable RGB LEDs. To keep the Christmas-lights aesthetic, they were actually assembled in place of non-addressable LEDs in a set of existing string lights, with two LEDs per letter of the alphabet for greater brightness adding up to 52 LEDs in total. Because the letters are only lit up one at a time, total current stays low, and power is easily drawn from the power input pin of the ESP32-S3. To control the display, there’s a web server running on the ESP32 which serves up a user interface for typing in messages and having them flash out in sequence, as they did in the show.
Most of the work was in cutting the letters out of EVA foam, but there’s nothing wrong with a quick Halloween arts and crafts project with the kids. It’s a fun decoration that can add a little vibe and curiosity to a Halloween party, so you might consider building something similar yourself next year.