Lesley Flanigan ITP

For more documentation go to www.seseyann.com/plinkjet

PLINK JET
By Lesley Flanigan and Andy Doro

ABSTRACT
Plink Jet is a robotic musical instrument made from scavenged ink jet printers. Plink Jet explores instrumentation as a process of structuring noise to create a musical experience, and performance as a relationship between human improvisation and machine order. Plink Jet also explores ideas concerning curiosity, invention, and expression regarding the role of technology in our everyday lives.

Keywords
Interaction Design, Repurposing of Consumer Technology, DIY, Performing Technology, Robotics, Automation

1. INTRODUCTION
Plink Jet is a robotic musical instrument made from scavenged ink jet printers. The mechanical parts of four inkjet printers are diverted from their original function, re-contextualizing the relatively high-tech mechanisms of this typically banal appliance into a ludic musical performance. Motorized, sliding ink cartridges and plucking mechanisms play four guitar strings by manipulating both pitch and strumming patterns like human hands fingering, fretting, and strumming a guitar. Plink Jet is designed to play itself, be played, or both. The result is an optionally collaborative performance between both the user and Plink Jet, with the user choosing varying levels of manual control over the different cartridges (fretting) and string plucking speeds (strumming).

2. INTERFACE
Plink Jet is designed to play guitar strings both manually and automatically. The interface consists of four toggle switches, four three-way switches, four dials, a single six-position rotary switch and a single power switch. Each of the four toggle switches and three way switches is associated with a single ink carriage. The rotary switch allows the user to select different pre-programmed patterns while a carriage is under automatic control.

2.1 Fretting
The guitar strings are strung across the printer mechanism where an optical sensor used to be. Cartridges slide up and down the strings and touch the strings just enough to change the pitch, similar to a slide guitar. The farther away the cartridge is from the plucking mechanism, the lower the pitch of the note.

Each carriage is controlled by a toggle switch and a 3 way switch. Toggle switches control whether its associated inkjet carriage is under manual or automatic control. While under manual control, the back and forth motion of each carriage is controlled by a three-way switch. While under automatic control, the carriage is controlled by a micro-controller containing programmed patterns of movement.

2.2 Strumming
The guitar strings are plucked by motors outfitted with a single thin metal strip that strikes the string as it rotates around. Four dials control the speed of the strumming motors. This happens irregardless of whether the associated carriage is under manual or automatic control.

2.3 Amplification
Inside each ink cartridge is a piezoelectric microphone used to pick up the sound of the guitar string being plucked as well as the ambient sounds of the sliding cartridge. Like an electric guitar, Plink Jet has a single half-inch output jack used to connect to an external amplifier.

3. TECHNOLOGY
The printer carriages and motors are from four inkjet printers. The controlling circuits and electronics are custom-designed. The optical encoder of each inkjet printer has been removed and replaced with a tunable guitar string that uses actual guitar tuning mechanisms built into the machine.

3.1 Circuitry
While under manual control, Plink Jet’s circuitry is completely analog. The only digital element is the micro-controller used in automatic mode.

3.1.1 DC Motors
A DC motor connected to an H-bridge chip controls the back and forth movement of each carriage. While in manual mode, the three-way switch controls the H-bridge with a 5VDC. While in automatic mode, the H-bridge is under the control of the micro-controller.

3.1.2 Stepper Motors
The strumming mechanism is driven by stepper motors, normally used for the docking procedure of the ink carriages. Each dial is attached to a potentiometer which controls the speed by changing the voltages on an oscillator chip. The oscillator signals are connected to hex divider chip, which acts as a stepper driver. The stepper signals are then relayed through a Darlington array before triggering the stepper motors.

3.1.3 Micro-controller
Plink Jet uses an ATMEGA168 chip containing six pre-programming patterns to control the fretting when a carriage is in automatic mode. A six-position rotary switch selects which pattern to use. When a carriage is in automatic mode, the ATMEGA controls the associated motor’s H-bridge.

Plink Jet at ITP Winter Show 2007

4. STRUCTURE AND IMPROVISATION
Plink Jet explores instrumentation as a process of structuring noise to create a musical experience, and performance as a relationship between human improvisation and machine order.

Structuring noise is fundamental to instrumentation and musical composition. As an instrument, Plink Jet amplifies the ticks, clicks, and hums of an ordinary printer. The incorporation of a guitar string highlights structure inherent in a mechanized system by relating pitch and rhythm directly to the mechanics. We made a musical instrument by designing an interface that gives a person playful control over the mechanical operation of these printers and combining the mechanical components with those of a traditional electric guitar.

Numerous options for playing Plink Jet back and forth between manual and automatic control creates a dialog between the player of Plink Jet with the robotics of the mechanisms themselves. Reflecting upon this interplay between a mechanical presence and human player, Eric Singer of LEMUR has said “I believe it is an entirely new experience for the human players. The robots create a physical, responsive presence (unlike synthesizers) which can profoundly affect the humans interacting with them. Because they move as well as sound, they take on a personality of sorts, and inspire the human players in a unique way.” [1] Intuition, playfulness, and improvisation are key concepts embodied in the operation of Plink Jet. Beyond its direct mechanical relationship to a human player, Plink Jet references a musical collaboration between members of a band and between a single musician with his or her instrument.

5. REPURPOSING OF CONSUMER TECHNOLOGY / DIY
Plink Jet also explores ideas concerning curiosity, invention, and expression regarding the role of technology in our everyday lives. The repurposing of consumer technology is a growing trend for artists and technologists in the DIY genre exploring circuit bending, hardware hacking and retro-engineering [2]. Artists who have used the mechanics of printers for producing sound include Paul Slocum with his dot matrix printer and Eric Singer's scanner-inspired musical instrument, GuitarBot. The innovative American composer Harry Partch also built many of his instruments out of trash and his own carpentry. Plink Jet’s emergence from the process of hardware hacking offers it for consideration as an Infra Instrument, a concept developed by John Bowers and Phil Archer. Infra-instruments come from beneath and are below the standards we would want of well-constructed instruments, but they are a valuable addition to the NIME research agenda with concern for technology, musical practice, and playful aesthetics [3]. Inside an ordinary ink jet printer are the same toy-like, clockwork mechanisms that have delighted people and sparked imaginations for centuries. In the creation of Plink Jet, we have investigated how human improvisation can interact with these mechanical forms. Plink Jet transforms the predicable function of a printer into a unique and irreproducible performance.

6. ACKNOWLEDGMENTS
We would like to thank Danny Rozin, Todd Holoubek, Tom Igoe, Gian Pablo Villamil.

7. REFERENCES
[1] Lotti, Giulio. LEMUR: League of Electronic Musical Urban Robots. < http://www.simultaneita.net/lemur2.html>.
[2] Ramocki, Marcin. DIY: The Militant Embrace of Technology. <http://ramocki.net/ramocki-diy.pdf>.
[3] Bowers, John, & Archer, Phil. Not Hyper, Not Meta, Not Cyber but Infra-Instruments. <hct.ece.ubc.ca/nime/2005/proc/nime2005_005.pdf >.

Posted by Lesley at 03:24 PM | Permalink | Comments (0) | TrackBacks (0)

*Completion scheduled for December 2007**

www.seseyann.com/plinkjet

Plink Jet is a robotic musical instrument made from scavenged ink jet printers. The mechanical parts of four printers are diverted from their original function, re-contextualizing the relatively high-tech mechanisms of this typically banal appliance into a ludic musical performance. Motorized, sliding ink cartridges and plucking mechanisms play four guitar strings by manipulating both pitch and strumming patterns like human hands fingering, fretting, and strumming a guitar. Plink Jet is designed to play itself, be played, or both. The result is an optionally collaborative performance between both the user and Plink Jet, with the user choosing varying levels of manual control over the different cartridges (fretting) and string plucking speeds (strumming).

The repurposing of consumer technology is a growing trend for artists and technologists in the DIY genre exploring circuit bending, hardware hacking and retro-engineering. Artists who have used the mechanics of printers for producing sound include Paul Slocum with his dot matrix printer and Eric Singer's scanner-inspired musical instrument, GuitarBot. Inside an ordinary ink jet printer are the same toy-like, clockwork mechanisms that have delighted people and sparked imaginations for centuries. In the creation of Plink Jet, we have investigated how human improvisation can interact with these mechanical forms. Plink Jet transforms the predicable function of a printer into a unique and irreproducible performance.

Current Development Documentation:

Printer Plays Guitar String Test.mov

Motor Test Slider Control Test.mov

Motor Test Switch Control Test.mov

Multiple Printer Control Test.mov

KEYWORDS:
Interaction Design
Repurposing of Consumer Technology/DIY
Performing Technology
New Instrument for Musical Expression
Robotics, Automation

Posted by Lesley at 08:44 PM | Permalink | Comments (0) | TrackBacks (0)

A collaboration with Andy Doro

The first iteration of GuitarBot2.0 ran off the PIC. Now, we are translating all operations to the Atmega (which can be programmed with Arduino).

Our main challenge was programming the DC motor so that we could control both speed and direction. This was accomplished by using the A3953 DC full bridge PWM motor driver. Todd has a nice basic explanation of how it works here.

1.Potentiometer connected to Analog In 0
2.PWM Out pin10 connected to Enable Pin (EN) on 3953. This controls the speed.
3.Digital Out pin3 connected to the Phase Pin (PH) on 3953. This controls the direction.
4.Motor output (MA and MB on the 3953)
5.12V into the bottom half of the breadboard to power the motor. The top half of the board is powered by 5V from the Arduino

motor control.mov
guitarbot play.mov

Next Steps:
1. building a low pass filter circuit to cut the sound of the PWM (high pitch buzzing) AND/OR control PWM speed through code
2. adjust range of potentiometer
3. controlling stepper off of Arduino
4. breadboarding Atmega circuits

Posted by Lesley at 02:18 PM | Permalink | Comments (0) | TrackBacks (0)

Speaker Synth
Speaker Synth is an instrument that plays natural feedback loops to output a musical experience. By "natural," I am referring to the sound of electricity. There is no external audio input to the system, the only components in the loop are the speakers, microphones, and amplifying circuit.

Speaker Synth is comprised of five autonomous feedback systems made of a speaker, LM386n amplifier circuit and piezo microphone. Individual controls include a volume potentiometer and power switch. By manipulating variables such as the positioning of the piezo in relationship to the speaker, the laying of hands and fingers on the speaker, and the inherent dynamics of the individual piezo and speaker, etc, users develop and play noise. The result are sounds take the shape of notes, chords, rhythms, and harmonies.

Speaker Synth demo1.mov (4min)
Speaker Synth demo2.mov (3.5min)

Further Development
More of these instruments will be made, with more in depth attention to the speaker, piezo and amplifier dynamics. I will also construct at least one with metal tubes attached to the speakers to experiment with a sound output that will not directly reflect back into the feedback loop. My intent is to have several Speaker Synths performed simultaneously, and produce a choral arrangement.

Essence of a Feedback Loop
The concept of a feedback loop is engaging, particularly in regards to consciousness and sense of self. Douglas Hofstadter refers to such a feedback loop as a "strange loop." We know our sense of self though layers of experiential, complex cycles that endlessly loop. Consider the phrase, "history repeats itself" in visualizing our process of living: we learn, add, subtract, and shape our lives, always returning to where we began to repeat again. To illustrate further, "Point a video camera at a TV displaying the camera's output, and you will produce a receding corridor of screens. Pixels make up the picture, but our interest is in the image, the tunnel of rectangles. Identity resembles that phenomenon. Never mind the neurons that make up our brain. Our emotions, others' responses and our repeated looks outward to the world and inward to ourselves shape what we call our self. Nor is ours the only loop we contain. We know how our friends see things; our mind houses their perspectives -- it has the formula for producing their thoughts." (Peter D. Kramer, Washington Post, reviewing Hofstadter's book "I am Strange Loop")

Speaker Synth was not intended as an exploration of such ideas, however the resulting interaction and sound inherently references the concepts of feedback loops in terms of consciousness. Speaker Synth is a "choral" instrument as opposed to either a classical or electronic instrument regarding its interactive and expressive qualities. The term "choral" addresses a voice. Something with a "voice" has an autonomous identity defined by its self. When powered, Speaker Synth plays its natural feedback loops, regardless of user interaction. When users do enter the system, they never have complete control, but rather, collaborate with the instrument. Hence, Speaker Synth embodies the sense of having has a "life of its own." It is self contained, self referential, self reflexive in both physicality and metaphor.

Posted by Lesley at 08:42 PM | Permalink | Comments (0)

"Because the essence of technology is nothing technological, essential reflection upon technology and decisive confrontation with it must happen in a realm that is, on the one hand, akin to the essence of technology and, on the other, fundamentally different from it. Such a realm is art." -- Heidegger

I want to investigate what it means to make objects that move, especially objects that move an invisible space between people.

Completed objects can be found at seseyann.com/objects.

Posted by Lesley at 06:04 PM | Permalink | Comments (0) | TrackBacks (0)

The Ravezooka is a musical weapon that shoots a wide range of powerful sounds based on the target's distance from the instrument.

Created with Benedetta Piantella Simeonidis, the Ravezooka was displayed at the 2006 ITP Winter Show. It has received a lot of press including We Make Money Not Art, Boing Boing, Wired Magazine, and Gizmodo.

Software: Max/MSP

Hardware: Arduino, Ultrasonic Range Sensor, Infrared Proximity Sensor, Luxeon LED, amplifier, laptop computer

Sound: Resembles an analog synthesizer manipulating sine wave frequencies with the aggressiveness of a machine gun. User controls include the range of frequencies (based on distance of target), distortion effects (based on handle slider position), volume control (potentiometer dial), and on/off (handle trigger switch).

Design: As a stylish musical weapon of audio destruction, the Ravezooka aesthetic is playfully based on a Bazooka.

How the Ravezooka Works:

The user straps the Ravezooka over his or her shoulders and squeezes the trigger handle to initiate sound and a beam of light. As the user moves the Ravezooka around, he or she will notice a change in the frequency range being played based on the distance of the person or object in front of the instrument. The closer the target, the lower the frequency range. The light emitted from the Luxeon LED will give a rough visual clue as to what person or object is being targeted. The user will also be able to slide the trigger handle back and forth to initiate a change in the distortion effect of the sound. The closer the handle is drawn towards the user, the greater the distortion. The user will also be able to control is volume by turning the potentiometer knob on the side of the Ravezooka. If the trigger handle is not squeezed, no sound will be played.

The sound of the Ravezooka is generated by MIDI data collected from the sensors. Using MIDI as protocol, there are two channels being processed in MAXMSP. Channel 1 is linked to the data collected from the Ultrasonic Range Sensor and Channel 2 is linked to the data collected from the IR Proximity Sensor. Sound output is played through a guitar or bass amplifier from the computer.

Prototype schematic for the Ravezooka:

Posted by Lesley at 08:55 PM | Permalink | Comments (0) | TrackBacks (0)