After seeing the Netflix series Stranger Things, I like many others wanted to build my own version of the wall. So for just in time for Halloween I did.
For those who haven’t seen the show-this wall was used to relay messages by lighting up a christmas light bulb to correspond with the letter on the wall. It’s crude and takes awhile to decipher, but there seemed like there was a lot of fun to be had in building it and sending messages.
I had a few restraints going into this project namely that this was something I wanted to build at home and be able to bring with me, so it couldn’t be wall sized. I wanted it to be close to the original with my own flair. Most importantly I wanted to be able to post messages to it using Slack, so that my team could message each other.
- Cork Board x1
- String of Christmas lights x1
- Fabric 1m
- Black Paint + Brush
- Stapler and staples
- OLED Screen
- 1000µF Capacitor
- 470Ω Resistor
- Addressable LED’s x30
- Level Shifter
- Wire (red, black and signal)
- Shrink Tubing
- Power Supply
- Power Connector (female)
- Stereo Audio Jack (or other three input connector)
All come together to make this 🙂
Assembling the Electronics
To create the controller to capture the messages and trigger the lights we created this layout. It takes in the signals and pushes them out to two places, the OLED screen and the Addressable LED’s through the level converter. The screen is nice for verifying the message, and displaying status messages about it being on, connected to the specified WiFi network, and errors. The level converter, resistor and capacitor were used to improve the current level going between the 3.3V board and the 5V lights. It works fairly well but there is defiantly a better way to get a clean signal through, as currently it occasionally triggers unintended lights.
To make it all come together we needed the ability to listen to incoming Slack messages posted to a Slack bot, or in a channel that the bot watched; To parse unusable characters out of the message and assign the rest to the LED representing on of the 30 characters available, and then send the message to the ESP8266 to spell out the message on the board and the LCD screen. Originally we considered doing most of the work on the ESP8266, but elected to move the heavy lifting to the cloud. This made the project faster and allowed us to extend the functionality without needed to load firmware on the board all the time.
Here is a link to the code for this project: Stranger Things code on github.
Assembling the Board and Lights
The string of lights was pulled apart to salvage the holders and the outer bulb.
Each case is wired with a replacement Addressable LED to allow us to control which light triggered when.
The board was prepped by drilling 30 holes spaced out in rows to accommodate the 30 characters. The fabric was then stretched and stapled to it to mimic the wallpaper from the original wall.
Next the wired addressable LED’s where pushed through the holes from the back of the board. Then installed in the salvaged bulbs to hang on the front. I then painted on the characters underneath the lights.
The Stranger Things Wall in Action
Finally a quick video of it in action spelling out:
“This is a test of the emergency broadcast system.”