The Hydraulophone: Instrumentation for Tactile Feedback from Water Fountain Fluid Streams as a New Multimedia Interface

This paper describes the construction of a MIDI interface that can be attached to an acoustic hydraulophone, or pneumatophone, or to an ordinary water fountain, or air fountain. This allows the fountain to be used as a haptic/tactile control surface or highly expressive fluid keyboard that provides gentle, soothing (soft) tactile feedback quite different from either the hard (solid) feedback of plastic keys, or the total lack of tactile feedback inherent in camera-based, vision-based, or proximity-sensing user-interfaces. We describe some of the difficulties in constructing such a multimedia input device, and some system architecture and signalling protocol considerations. In particular, we describe a modular self-healing architecture for fluid-based user interfaces. The architecture uses small microcontrollers, strung together, to obtain a large number of analog inputs in a small size low-power distributed system that is long and slender and can be easily waterproofed and sealed inside water pipes, manifolds, fluid chests, or fountains