Wobble Sphere

Wobble Sphere is a new experimental playful installation that I'm currently working on. 72 touch-sensitive metal springs and LED rings sit on a large sphere (~50cm diameter), illuminated by various playful interactions and ambient animations.

The installation (and this page) are still in development!

The idea for making Wobble Sphere was born from the desire to make a non-flat Wobble Garden, and when we used a 360 camera to maka a 'little planet' photo of Wobble Garden (this photo), it looks pretty much like a sphere.

From there, I followed a rabbit hole into research of sphere tilings, ultimately arriving at polyhedra with 12 pentagons and a large number of hexagons (they typical football tiling). For my first prototype I ultimately settled on this shape with 60 hexagons:

After precisely modeling the pentagons and hexagons, I imported them as board outlines into my PCB software (in this case Diptrace), and figured out how to route the touch- and LED signals to the microcontroller.

I decided to use a Teensy 4.0, mostly because it was shiny and new, but also promised a extremely high performance and a 480MBit serial usb connection to the PC. Additionally the active community around the Teensy produced cool libraries, such as the TriantaduoWS2811 library, which allows controlling 32 LED strips in parallel without any CPU usage (using only FlexIO and DMA). I ended up using that library, using a 'strip' for each pentagon and each of its 5 surrounding hexagons.

As a little easter-egg, I decided to put small drawings on the hidden side of the PCBs, and I commissioned Caitlin Goodale for the artwork. It turned out great, and I'll probably commission small pieces for all my future PCBs!

I kept the door stopper springs and LED rings I used in Wobble Garden as the combo worked quite well, and 3D-printed holders that the door stopper springs could be attached to with their screws. Combined with the soldered PCB-to-PCB connections, this was surprisingly rigid and gave the sphere a satisfying stability.

Each of the pentagons connects with a ribbon cable to a central mainboard that houses the Teensy and the touch sensors.

I'm still working on a proper mount, so far I just used some aluminium extrusions to make a quick 'popsicle' style stand, but I'm also considering suspending the sphere in free air using thin wires.

On the software side, I'm re-using the code I wrote for Wobble Garden, which uses Python and pygame for rapid prototyping of animations and sends the LED data over USB to the Teensy, which renders it and sends the touch data back to the Python script. This works fairly well, and allows me to get a performance of more than 150 fps, leaving a fair bit of performance leeway for larger spheres. The interactions and animations I have so far are all procedural and fairly simple (see video below), and I'm planning on spending more time on small games, visualisations and other specific applications, potentially opening up the python library to other artists too.

Wobble Sphere is soon available for exhibitions and festivals! Please contact me to discuss. I'm also open to commissioned versions and different sizes.

• Creation of first prototype: London, March-June 2020
• Presentation at A MAZE. Berlin - Total Digital 2020 (video only), July 2020
• to be exhibited in PlayBern, October 2020