Gourds: system overhaulPosted: May 12, 2015
With the exhibition just a few weeks away, it was time to upgrade the motion tracking system inside the gourds. I had been prototyping with the crude accelerometers in Wii controllers, because of the simplicity of the technical setup. But I wanted to get a better sense of how people would respond to the instruments, and for that, I needed more responsive sensors, and a more stable system.
I decided to work with Xbee series 2 radios, which operate on the Zigbee wireless standard. These radios are capable of connecting to one another in ways that the older series 1 xbees could not. In particular, I was interested in the capacity of the series 2’s to form a “mesh network,” where multiple radios form a hierarchical network, with multiple radios communicating in multiple ways at the same time, rather than a simple 1-to-1 relationship.
I built a new circuit. This one uses a 9-DOF sensor that combines gyroscope, accelerometer, and magnetic north sensor data to understand exactly where it is in 3 dimensional space, with no gaps. The sensor sends its data to a central computer running MaxMSP and Ableton Live (audio processing) via the Xbee network. Then, the computer sends audio signals back to the gourds over bluetooth, just like any commercially available wireless speaker.
This new set up allows any movement of the gourd to create a sound output. Players have a much more nuanced sense of feedback than before. Hopefully, this inspires a deeper curiosity for and exploration of the gourd’s capabilities. Players have an opportunity to gain control over the sounds the gourd makes without any instruction, simply by noticing patterns in the ways their movements generate sound responses.