Record a musical composition by squeezing, tilting, shaking and other playful gestures.
Pressure sensors are hidden underneath the exterior fabric and the hardware is located inside. Each instrument (ball) is a node on the network and multiple nodes can publish data to the same software program. The ball is completely wireless and contains a rechargeable battery.
I used the Sense Stage platform to set up the network and pass data wirelessly using OSC messages. Sensor data is sent wirelessly over an Xbee network via OSC (Open Sound Control) to a host computer running Max MSP. Each sensor is mapped to a sound loop and the pressure placed on it determines the amplitude. Jason Heath assisted with the software design in Max and added calibration feature was added due to the unpredictable nature of conductive fabric and the heat that was generated from use affected the resistance.
Conductive fabric pressure sensors are hidden underneath the exterior skin of the ball. Each sensor is mapped to an audio loop and this allowed the user to use a squeezing motion to create a musical composition. I prototyped several versions of the conductive fabric sensors using piezoresistive, conductive and semi-conductive materials to get the most responsiveness. An accelerometer and mechanical buttons are also hidden inside the ball to allow the player more gestures for musical expression. The basis of the sensor design was inspired by Dr. Adrian Freed, former Research Director at the Center for New Music and Audio Technology (CNMAT) at UC Berkeley the work of Berkeley's CNMAT and his former student Hannah.