ï~~A Touch Sensitive Dance Floor/MIDI Controller
Russell Pinkston
Jim Kerkhoff
Mark McQuilken
The University of Texas at Austin
512-471-0865/
[email protected]
ABSTRACT: A prototype MIDI Dance Floor has been developed which can transmit precise position,
velocity and pressure information in the form of standard MIDI messages. It consists of a large number of
Force Sensing Resistors (FSRs) attached to four 4' x 16' plastic sheets, covered with thin polyethylene
foam, designed to be placed beneath a standard Marley floor. The FSRs are typically arranged in such a
way as to form a 16' square grid with 64 force-sensitive zones, each of which is assigned a separate MIDI
Note and Continous Controller number by a 64-channel Voltage/MIDI Interface.
Introduction
In recent years, numerous systems have been devised for the purpose of capturing the movements of
dancers and converting them into signals which can be used to control various aspects of a
musical/theatrical performance. The technological means which have been utilized are many and varied,
ranging in complexity from simple on/off triggers placed on the floor, to highly sophisticated systems
incorporating ultrasound, radio, and real-time visual analysis. All of these systems, however, tend to
reflect one or the other of two fundamentally different approaches: One approach involves what may be
referred to as "passive control." It is based on the ideal that dancers should be completely free to move
normally, that it is the responsibility of the system to detect their movements accurately and respond to
them in an appropriate manner. Dancers using such a system would not necessarily have to be conscious
of how their gestures were being used for control. Consequently, there should be no artificial restrictions
on the creativity of either the choreographer or the performers. The other approach involves "active
control," and it requires that the dancers be very aware of the specific effects of their movements. The
ideal here is that a system should provide dancers with very precise control, allowing them to play music
and/or produce sounds directly through highly specific, conscious actions. Once the dancers have learned
to manipulate such a system effectively, they should be able to "play it" like a musical instrument, with
much greater sensitivity and expressiveness than they could with a passive system. There are technical
and aesthetic pros and cons to each approach, which are beyond the scope of this paper.
The MIDI Dance Floor
The MIDI Dance Floor is an experimental prototype for a system capable of being used for both active
control and passive sensing, which would not require the dancers to wear or carry any special materials,
and which would not be prohibitively expensive to produce. It utilizes Force Sensing Resistors (FSRs)
from Interlink Corporation, which are made of a thin, flexible, and relatively strong material and are
manufactured in a variety of shapes and sizes. The FSRs are very sensitive and produce a useful range of
resistance which varies in inverse proportion to the amount of force applied to them. We employed a total
of 128 24" FSRs, affixed to four 16' x 4' strips of heavy duty plastic sheeting, 32 per strip. 16 pairs of
FSRs, wired in parallel, were attached to the plastic with contact cement and laid out as shown below.
This arrangement was adopted to cover the maximum area and in order to place the solder tabs at the
center of each section for protection. Wiring pairs of FSRs in parallel effectivly created-16 4-foot long
FSRs, which halved the number of A/D channels required by the interface and still provided a reasonably
dense number of sensors per square foot. The FSRs were then covered with a thin layer of polyethlyene
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I C M C PROCEED I N G S 1995
