Fedde ten Berge

The Shroom focusses on the vibrations that occur on different levels in the psychical reality of the artwork. Electromagnetic, acoustic, material and structural vibrations are picked up by different sensor strategies, which enables The Shroom to ‚respond’ to the approach of the audience with carefully designed sound. In this way the visual design of the object comes in close relation with the sound design. 

The sculpture is equipped with different sensors. The ceramic clay is gement and baked with steel dust which gives it a very high resistance and on the inside is a layer of conductive alluminium foil. This makes the bowl a big capacitor that is very suitable for proximity field capacitive sensing. No external capacitive sensors are used. All the sensor and audio processing in the Shroom is build with BELA: a low-latency audio board for embedded applications. The Bela runs on upon a PRU on the Beaglebone Black. On the second PRU of the Beaglebone Black there is code which does the capacitive sensing on multiple frequencies. I developed this code in close collaboration with Andrew McPherson and Tim Walther. 

Directly under the bowl the Bela is mounted and two electret microphones are facing the inside of the bowl. These are used to pick up the acoustic vibrations. A piezo sensor is fitted against the inside of the bowl. This is used to pick up the knock vibrations in the ceramics. I use the knock sensor to open a gate for the electret microphones. On the base of the structure an accelerometer is attached to pick up the structural vibrations. All of these sensors are integrated in to an interactive sounddesign that is made within Puredata. The Puredata patch is compiled into efficient C-code with the Enzien Heavy compiler.