Students/michaelberger/250B/

MUSIC 250B, Winter 2009, Research Page

This research page has been completed as part of the following assignment:

    Wiki "Community Service" Project

    As an end-of-term deliverable for 250b, prepare a helpful and factual Wiki page on the 
    ccrma wiki on a topic relevant to the course. The goal of the wiki page is to create a 
    repository for the facts, links and processes which sustained your work in 250b this term. 
    The target audience for this page is the collection of future CCRMA students interested 
    in HCI and music taking the 250 series of courses. Hopefully, your work will not only 
    inspire their future work but will also act as a valuable resource from which they can get 
    a head-start on similar projects, in a sense, "standing on the shoulders of giants" 
    (yes, this means you are all "giants").

GRIP MAESTRO

• need, impetus, intention
• description

Background, the Mach 1 (from Music 220C, Spring 2008)

• Equipment & Parts (Summary -- for more details see my 220C research wiki linked above)
  • 1 x GRIP MASTER hand exerciser. (5 lb resistance for each of 6 springs.)
  • 6 x Hall Effect Sensors -- available here.
  • 6 x (0.0625" 2.45lb Magnets).
  • 1 x Arduino Diecimila with 1 x Arduino Protoshield Kit and 1 x mini-bread-board

• Construction
  • Tools

• POSTER SESSION @ CCRMA OPEN HOUSE 2008!

  Introduction
     Part of the Michael's ongoing research (supported by the Social Sciences and 
  Humanities Research Council of Canada), the “GRIP MAESTRO” is the composer's 
  latest attempt to incorporate real physical resistance and haptic feedback into 
  an electroacoustic performance interface. The goals of this specific project 
  are to take advantage of a simple physical gesture (not previously utilized by 
  an existing acoustic instrument: see next section), and, by incorporating physical 
  resistance, create an “easy to learn / difficult to master” interface for the 
  creation of, and control over real-time electroacoustic performance in both a 
  solo and ensemble setting.
     The “GRIP MAESTRO” is a modified hand exerciser called a “Grip Master” 
  (see section below). By measuring the position of the pads on the device and carefully 
  mapping them to parameters of music creation, Michael hopes that the “GRIP MAESTRO” 
  will provide the feel, control, and aural feedback necessary to be an effective 
  interface between performers and their music, and between audiences and their 
  performers.
     Presently there are two mappings of the control data prepared in the ‘strongly 
  timed’ programming language, “ChucK”. Michael is presently in the planning stages 
  of a third, but there are a multitude of potential applications and mappings for 
  which the “GRIP MAESTRO” is ideal.

~

  Movement & Resistance
     The action of gripping and squeezing by the hand(s) was chosen  early on to 
  be the the central aspect of this interface.  Many existing acoustic and electro-
  acoustic instruments rely heavily on the performers hands as driving controlling 
  agents, but few utilize and emphasize the motion of gripping specifically.
     In order for an interface to take full advantage of the motion of this activity, 
  it needs to provide physical feedback and/or resistance to the activity consistently 
  for the full range of its motion. It is very important to the composer that any given 
  interface feature a real and innate physical feedback/resistance to the performer’s 
  actions so that he or she may feel as closely in tune with that interface as possible 
  and so that the sounds that are produced by the performative actions relate to the 
  nature of the actions themselves.

~

  Grip Master
     A ‘hand-exerciser’ seemed the best choice for a physical object that: a)takes 
  advantage of the full range of motion involved with the action of ‘gripping’, and 
  b)provides real physical feedback/resistance to that action.  
     The ProHands “GRIP MASTER” hand exerciser (available here) was quickly discovered 
  and decided upon by Michael, who was drawn to several of this specific model’s key 
  features. Among these were: each finger has its own independently but equally 
  resistant pad, the palm has its own moderately rotating resistant pad, the devices 
  are available in a number of different resistances, the small, transparent, yet 
  solid construction makes the device easily upgradable, and its plastic body is 
  naturally electrically insulated.

~

  Sensors & Sensing
     In order to translate the position of each of the GRIP MASTER pads to the 
  computer as a number, Michael chose to attach magnets to each pad paired with 
  Magnetic Hall Effect Sensors attached to the central body of the device. A 10-wire 
  ribbon cable is used to connect the necessary Voltage (+5V) and Ground for each 
  of the 6 sensors (each with a wire with which to take readings), and Voltage and 
  Ground for an indicator LED (see circuit diagram and images below).  Each sensor 
  and magnet pair needed to be directly aligned (on-axis) to ensure the most linear 
  readings possible.  Two sensor/magnet pairs were placed on the palm pad in order 
  to determine the angle of that pad. 

~

  Mapping
     Utilizing excerpts of Max/MSP code by Daniel Jolliffe, “Arduino2Max,” Michael 
  constructed a Max-patch (Serial2OSC.maxpat) that filters the incoming ‘analog’ 
  readings from the Arduino board, and broadcasts them via the U.C. Berkeley-developed 
  UDP network protocol, Open Sound Control.  He then set up two programs in Ge Wang 
  and Perry Cook’s ChucK to receive the messages (since ChucK is presently unable 
  to receive data directly from the Arduino).
     The first program (GripMaestro-SinOsc.ck) maps the incoming floating point 
  numbers (0. through 1.) of each of the four finger pads to a different sine 
  oscillator’s frequency, and the palm pad to the sounds’ panning and overall 
  amplitude.  This simple example demonstrates the degree of control that the 
  performer has over musical materials with the “Grip Maestro.”
     The second program (GripMaestro-Granular.ck) is based off of code by Kyle 
  Spratt from his piece, “I Miss My Uncle Charles.”  The original program listens 
  to an incoming audio signal and parses it into small repeating “snippets” 
  depending upon the variables that are given and controlled by the user by editing 
  the ChucK code and replacing the already running “shred.”  In this mapping however 
  the parameters of the program are controlled entirely by the “Grip Maestro”: the 
  four finger pads control each of four sets of these original parameters where as 
  the performer depresses a pad the amount of delay time increases, and the palm pad 
  controls the playback speed of the audio signal, the size of the snippets, and the 
  overall amplitude.  The use of the “Grip Maestro” allows for much faster and smoother 
  changes of these control parameters, which in turn produces a more personal, 
  potentially emotive performance.

CCRMA CONCERT ~ Granular 1.0 Video

The Road to the Mach 2

• revising the Mach 1
  • hardware
  • software
    • arduino
    • mappings

• expanded intentions
  • the plan
  • new parts
  • new construction (ongoing)
  • new mappings (forthcoming)

LINKS

• Back to Research Topics
• Course Site
• Course Wiki