Growing the Tree
From that initial prototype, we needed to scale up to something much bigger. To do so, we got a coat rack from Argos that had a very tree-like shape and connected wires to balls of aluminum foil wrapped in aluminum foil tape to increase conductivity and give a bigger surface for touch when interacting with the tree. The wires were originally connected to alligator clips that were then connected to the raspberry pi touch hat, but this gave us issues with inconsistent loss of input as the tree was being moved. When testing each input individually, the issue wasn’t happening. We decided that it was likely that there was problems with the connections between the clips and the wires, so we decided to hook wires up directly to the touch hat that would be soldered to the wires on the tree once we had finished the code of the experience.
Billy then started working on a python script that utilizes pygame and the Adafruit Capacitive Touch hat library to build the interactions using all 12 available inputs. While he was doing so, I started dressing the tree in a way that would make it feel more technological and tree-like. I wrapped the tree in Gaffer tape to protect the wires, and painted the tree with a copper spray paint.
We attempted to add LEDs and elwire to the tree from the GPIO pins on the Raspberry Pi, but because of the size, we weren’t able to get something that looked or felt the way that we wanted. We decided to build the game experience of the tree without visual feedback as a result, and planned on adding code that could potentially turn on a blacklight when the puzzle had been solved to give the tree a slightly otherworldly feel to the design.
I also 3D printed a carrier case for the Raspberry Pi that I had found on Thingiverse(2) with hexagonal holes for cabling. Once the code had been nearly finished (and could be easily updated by connecting to the pi via ssh), I soldered the wires connecting the wires from the tree to the wires from the pi, and attached the carrier case to the underside of the tree. Testing with the soldered connections showed that the touch input was much more consistent than with the alligator clips. This also made the tree mobile, so as long as we had a portable battery (and were careful), we could potentially set up the tree anywhere.
The last step was to continue to dress the tree further while Billy made final changes to his code for the tree. I added fake foliage covering the carrier box, exposed electronics, and speaker, and some additional foliage to give the impression that there were more branches to the tree. I also spray-painted some polystyrene balls to give new texture to the tree and the impression of knobs or fungus growing along the outside. Our blacklight was damaged during room setup, and we were happy about the look of the tree, so we decided not to include this element in the final design.