This is an art installation I wired up and programmed for the National Multiple Sclerosis Society. I worked with artist Sara Garden Armstrong. The sculpture and the patterns of light flowing through it present an abstract representation of the effects of MS on nerve cells.
Early on it was decided to use LED strips for this piece. As needs for the piece changed, I iterated on different types of LED strips and different microcontroller boards to drive them: Arduino Mega, BeagleBone, and finally Teensy.
The final control box utilizes a Teensy 3.1 to run the program controlling the LED strips. It produces the signal to set each LED’s brightness and color and a 74HCT245N acts as a level shifter to get the Teensy’s 3.3v signal up to the 5V needed. There are 8 runs of LED chained strips with over 3000 total LEDs. I settled on using the Teensy after testing and verifying that it could handle the number of LEDs required at the speed required. It had the advantages of simplicity and robustness over the previous setup I had that used a BeagleBone. Both of those had the advantage of bandwidth over the Arduino Mega which could not drive this many strips of this length fast enough. The LEDs used are the WS2812 type and the strips are 60 LEDs per meter. My program on the Teensy leverages the OctoWS2811 LED library from PJRC.
In the control box pictures below you’ll see a second set of everything as a backup since this is a permanent piece and needs to last many years. Those control box pictures still show one final soldered board setup and breadboarded test setup. After we were sure everything was absolutely as we wanted it I created a second soldered board to replace that one.