Sledgehammer-operated Keyboard

FALL 2011: V.07 N.02: CAA Conference Edition 2011

 
Taylor Hokanson
Assistant Professor of Art
Oakland University

Like all effective artworks, my most popular piece to date hits upon a universal truth:  people like to smash things.  The Sledgehammer-operated Keyboard [1] (SHKB) was built to both withstand and encourage the rough treatment that its name invites.  When participants use a hammer to strike its silicone rubber keys, SHKB produces standard letters and punctuation on a computer screen.

Sledgehammer-operated Keyboard, 2005 – ongoing, Taylor Hokanson, Human-Computer Interface, image: Taylor Hokanson.

Sledgehammer-operated Keyboard, 2005 – ongoing, Taylor Hokanson, Human-Computer Interface, image: Taylor Hokanson.

Typical USB keyboards are technically unsophisticated and inexpensive, and operate at signal level voltages.  This last factor is crucial, as it means that quasi-informed manipulation will not result in life-threatening electrical exposure.  Through experimentation, I discovered that most any keyboard circuit is based on two groups of exposed contacts.  When a conductor bridges any pair of individual contacts between groups one and two, the chip at the heart of the circuit sends a particular character to the computer for display.  One can easily “map” the location of every letter on the circuit with a paperclip and a notepad.  I’m certainly not the first to take this approach, and many detailed tutorials can be found online. [2]

Once I understood how a keyboard functioned, I set about attaching conceptual significance to this discovery.  Like all technology, computers are intended to extend the range of our personal, physical ability.  Yet computers are also incredibly frustrating, often replacing old problems with new ones.  While touch-typing, email and texting make communication easier to perform and distribute, they do nothing to improve its content.  To paraphrase Andrew Keen’s argument in The Cult of the Amateur:  The easier it is to do something, the easier it is to do it wrong.

Since its first show in Chicago in 2005, SHKB has undergone five major revisions.  Each revision added function and complexity to the work, but also increased the number of elements that can fail and the amount of support equipment that must accompany the piece to each show.  The most recent exhibition took place at Techfest (2011), a yearly event held at the Indian Institute of Technology (IIT) in Mumbai.

Sledgehammer-operated Keyboard at the India Institute of Technology, 2011, Taylor Hokanson, Human-Computer Interface, image: Taylor Hokanson.

Sledgehammer-operated Keyboard at the India Institute of Technology, 2011, Taylor Hokanson, Human-Computer Interface, image: Taylor Hokanson.

IIT had no funding to support shipping, so my first task involved reconfiguring SHKB into five modules that fit into two carry-on-size bags.  These units had to be small and light enough to meet airline regulations, yet robust enough to endure three days of constant hammering from the anticipated 30,000 attendees.  I used a modified version of the Interlocking T-Bolt Construction (as defined by the design firm Oomlout [3]) method to allow for modular assembly.  This approach produced strong, temporary, mechanical connections without adding thickness to the base of each module (already strictly limited by suitcase depth).

In addition to an updated shipping solution, I took the occasion of the IIT show to add depth to the interactive aspect of SHKB.  I wanted to create an input that was simple, cheap, and pressure-sensitive.  This input would allow SHKB to map something that a typical keyboard could not.  Research revealed that piezoelectric elements met all of my requirements.  Though piezos are most commonly used as audio buzzers (output), they can also be induced to “listen” for vibrations rather than produce them (input).

When a piezoelectric material encounters vibration, this mechanical deformation is converted to analog voltage.  Instead of producing the yes-or-no result that typifies digital signals, analog voltage is used to track the range of values that fall between 0% and 100%.  The intensity of a vibration encountered by a piezoelectric sensor correlates directly to the size of the voltage that it will produce.

An analog signal must be converted to a digital signal in order for a computer to understand its content.  This conversion is done with a microprocessor or chip called an “A/D” (or analog to digital converter).  I picked the Arduino UNO [4] for this purpose.  Though more expensive than a chip designed expressly for A/D conversion, the Arduino requires much less effort when it comes to circuit assembly.  In fact, aside from the Arduino and piezoelectric element, only one additional passive component was required for each sensor to function.

Arduino/piezo force-sensor layout, Wiring (circuit layout application), 2011, image: http://arduino.cc/en/.

Arduino/piezo force-sensor layout, Wiring (circuit layout application), 2011, image: http://arduino.cc/en/.

The Arduino platform is open-source, meaning that none of the information about its design is withheld from its target audience of artists, designers and engineers.  This openness encourages Arduino users to expand upon the platform without fear of copyright infringement, and to share the results of those efforts with the broader community.  Though I am no expert programmer, I do have a working knowledge of Adobe Flash and Actionscript 3.0 (AS3).  A quick Google search revealed a code library called “as3glue” [5] that allows the Arduino to communicate with Flash.

Using AS3, I created a simple graphical interface for SHKB.  In addition to sensing which key is pressed, the new design can also record the amount of force involved.  For the IIT show I correlated impact to font size, allowing the audience to control the height of each letter depending on how hard they struck its key.  As this variable is controlled by software, pressure readings could be applied to any text-related feature (such as color, position, font, etc.).

Sledgehammer-operated Keyboard at Techfest 2011, Taylor Hokanson, Human-Computer Interface, video still: Taylor Hokanson.

Sledgehammer-operated Keyboard at Techfest 2011, Taylor Hokanson, Human-Computer Interface, video still: Taylor Hokanson.

Although so-called “New Media” art can be extraordinarily complicated to produce and exhibit, such works can often reach a broader audience through the common reference point of familiar technology.  On the one hand, SHKB can be considered in the context of modern computing, where the change in scale, material, and interactive mode is accessible to a non-art cohort.  Yet, at the same time, the work has a parallel existence in critical theory, referring to Concrete Poetry, Dada, Fluxus, and the aura of digitally produced artwork.

Endnotes
1.Taylor Hokanson,  Sledgehammer-operated Keyboard, http://www.taylorhokanson.com/shkb, (accessed February, 2011).
2.Instructables user “randofo”, Hacking a USB Keyboard, http://www.instructables.com/id/Hacking-a-USB-Keyboard/,  (accessed February, 2011).
3.Instructables user “oomlout,” How to Make Anything (Using Acrylic and Machine Screws) ,http://www.instructables.com/id/How-to-Make-Anything-Using-Acrylic-and-Machine-Sc/, (accessed February, 2011).
4.Various authors (wiki), Arduino – Homepage, http://www.arduino.cc/, (accessed February, 2011).
5.Bjoern Hartmann, “as3glue,” http://code.google.com/p/as3glue/, (accessed February, 2011).