ESP32 based pixel mapped LED array controlled by DMX over ArtNET
PixelSun is an array of 200 individually addressable LEDs remotely controlled by DMX data sent over ArtNET wirelessly. The physical layout of the LEDs are mapped by special pixel mapping software that can play colorful video animations across the LEDs, like a giant TV screen.
I actually didn't have to do much coding on this project. The bulk of the work was all research, configuration, and setup. It's amazing how much technology already exists out there - sometimes you just need to connect the pieces and wire it up.
I've explored bitmap, audio-sensitive, and procedurally animated LED displays in past projects. I wanted to look into the concept of pixel mapping as a means of animating a large LED display. This gave me both a software and hardware decision to make, with two subgoals:
- Hardware: Make a project able to receive real-time DMX serial communication, similar to my ImpactWings project. This time around however, I wanted to receive that data over a local network from my computer.
- Software: Find the best inexpensive pixel mapping software capable of sending out ArtNET animation data.
- Hardware: Using an Espressif ESP32 microcontroller would let it all work over WiFi! These are increasingly popular Arduino-compatible chips that are great for networked projects like my remote-controlled DK-Rover.
- Software: I found this excellent Sparkfun article on how to send ArtNET data to an ESP32 and LED strips using Resolume. That's great but Resolume is expensive professional software and I needed something simple. I looked into Lightjams, Enttec Elm, xLights, and ended up going with an app called LED Lab because of its powerful simplicity, and it could run on my Mac.
The final piece was the addressable LEDs themselves. I often work with WS2811 / Neopixel LED strips and found these really cool diffused LED "fairy lights" at Adafruit that are WS2811 compatible with a few quirks.
All of this uses my favorite LED library for the Arduino, FastLED. I was able to use existing code from the ArtnetWifi library, which builds on FastLED and the ESP32's WiFi capabilities.
- The ESP32 connects to the WiFi network and displays its IP address on an onboard LCD.
- LED Lab streams DMX data over the network to the ESP32 at about 30 frames per second.
- The ESP32 outputs the color data to 11 LED strands using FastLED and the WS2811 protocol.
With so many hand wired connections and power requirements exceeding what a USB port can provide to the ESP32, testing was really important for this project. My final goal was to suspend the entire thing from the ceiling, so everything needed to be modular for installation. I was happy to find the ESP32 logic running at 3.3 volts could power the 5 volt LEDs without any visual artifacts and would not require a logic level shifter.
Contrary to what Adafruit says, the middle wire of each LED strand is not the data line, it is ground.
Each LED strand is soldered to a JST PH connector and plugged into 5 volt power on the final circuit for even power distribution. The entire project uses about 600mA of current, so an external DC power supply is used.
PixelSun final installation: mounted to the ceiling with 11 LED strands extending out from the central light fixture to the edges of the room.
The position of each LED strip is mapped in 2D space using LED Lab's advanced mapping tool. Now colorful shapes and images can be projected across the entire LED installation!
Note that I didn't have to run any wires between strand ends, as these quirky LEDs have permanently set addresses. That means the data is able to pushed out simultaneously in parallel from a single data pin on the ESP32!
