For the midterm for Physical Computing, Alan Peng and I built a laser harp MIDI controller.
After we were assigned as partners, Alan and I spent some time brainstorming about what we wanted to make. We came across Klanglichter, a really beautiful laser harp project made by Tobias Kreter and Onat Hekimoglu, and were inspired to try and make a similar instrument. We decided to make our laser harp a MIDI controller, so that we could combine our serial communication lab and midterm assignments into one project.
- A frameless laser harp that used a single, powerful laser reflected off of a mirror attached to a rapidly rotating DC motor to create the illusion of multiple laser beams.
- A framed laser harp that used multiple lasers, each pointing at somet type of light sensor (photoresistors, phototransistors, or photodiodes).
We decided to go with the second approach, because we were a little nervous about working with powerful lasers that could potentially blind us or others and a DC motor that would require more than 5V of power.
Our first step was to sketch out a few rough ideas of what the harp might look like:
We decided that we wanted to have seven strings so that our harp could play a musical scale, so we knew that we needed at least seven laser diodes and seven light sensors. We ended up buying a cheap 10-pack of red 5mW laser diodes and a 20-pack of photodiodes on Amazon. We also bought some MIDI jacks that we didn’t end up using, because we later decided to send MIDI over the Arduino’s USB port for simplicity and ease of fabrication.
We designed the enclosure in Adobe Illustrator, including holes for our components and the Arduino’s USB port, and then laser cut all of the parts out of matboard from Blick Art Materials.
Since our Arduino wrote MIDI data to serial over USB instead of a MIDI jack, we needed to run an additional program to convert route the MIDI data from serial to a virtual MIDI port on one of our computers. We used SpikenzieLabs’ Serial-MIDI Converter to do this.
We also used Kurt Revis’ MIDI Monitor to verify that we were actually sending MIDI data to a virtual MIDI port.
Once that was working, the last thing that we had to do was configure Ableton Live to read from the virtual MIDI port.
For Physical Computing, we were asked to observe a piece of interactive technology in public and take some notes about how it was being used. I chose the elevators in the Tisch building.
There were a few things that people seemed to find difficult about using the elevators:
The buttons light up very dimly when pressed, so it’s difficult to tell at a glance whether a given button has already been pressed. Multiple times, I saw people press a button for a floor that had just been pressed by someone else a few seconds ago.
Most of the floors, except for the first floor, don’t have floor indicators that show where the elevator is and which direction it’s headed in. On higher floors, people couldn’t easily tell how far away the elevator was, and couldn’t tell which direction it was headed in until after the doors opened.
Another thing that I noticed was that when someone needed to stop the elevator door from closing, they were more likely to hold their hand in the path of the door vs. using the “Door Open” button, taking advantage of the safety feature that prevents the elevator from closing when there’s something blocking the infrared light sensor in the door. This suggests to me that blocking the door with your hand to keep it open is a more intuitive interaction than holding down a button.
What is space like? Hedwig and the Angry Inch takes place on the stage of a Broadway theater, the Belasco, on the former set of Hurt Locker: The Musical. The space is modified by lighting and projections over the course of the show.
What is time like? Time is linear, as the musical takes place over the course of Hedwig’s performance. However, the musical also uses a flashback structure as Hedwig re-enacts several moments from her life.
What is the climate like? The musical takes place entirely indoors, so it’s hard to say what the climate is like. I’d guess that the climate is like the inside of a theatre, dark and maybe air-conditioned.
What is the mood? What is the tone? The mood of the musical is at times angry and defiant, at others humorous, at others sad and melancholy. The rock and roll music gives the musical a passionate tone.
What is the pattern of sound? Hedwig and the Angry Inch, like most musicals, alternates between speaking and singing. The music takes a lot of inspiration from early 1970s glam rock, punk, and power ballads. Hedwig’s backing band consists of the typical rock instruments - drums, bass, electric guitar, and piano.
Is this a public world, or private? What are its class rules? The conceit of the play is that Hedwig is performing for the audience, so in that sense the world is public.
In what patterns do figures arrange themselves? Hedwig is the central figure of the play: Yitzhak and the band revolve around her. Hedwig and Yitzhak also interact frequently as a pair. Tommy Gnosis is depicted off-stage by himself.
How do figures appear? The characters are fairly exaggerated - this is a glam rock musical and they are performing for the audience. Hedwig isn’t a caricature, but her emotions are depicted in a larger-than-life way.
How do figures dress? Hedwig wears a wig and dresses in an androgynous, glam rock style, in keeping with her genderqueer identity. Later in the play she changes into a dress. Yitzhak wears masculine clothing, probably all black since he’s a roadie, until the end, at which point he changes into “stunning female drag.” The Angry Inch are dressed “flashily but affordably.” Tommy Gnosis has a silver cross painted on his forehead, and probably dresses like a rock star.
How do figures interact? Hedwig and Yitzhak take passive aggresive snipes at each other until they reconcile at the end. The Angry Inch mostly keep to the background.
Who has power on this planet? Hedwig exerts power over Yitzhak by forcing him not to perform drag as a condition of their green card marriage, because she feels threatened by his talent.
What are the language habits? Hedwig alternates between monologues to the audience and dialogues with herself in which she plays both parts. Hedwig’s language is definitely the language of feelings - defiance, lust, love, anger, despair, vulnerability, and self-acceptance.
- First image: Yitzhak sullenly introducing Hedwig as she parachutes onto the stage to sing “Tear Me Down”.
- Last image: Hedwig walking offstage into the light as Yitzhak (finally in drag) and the band sing the phrase “Lift up your hands…”
- Central image: Hedwig singing “Angry Inch”, a song about her botched sex change.
- Why was it essential to move through the central image to get from the first to the last? “Tear Me Down” introduces us to Hedwig as a divided character, compared to the Berlin Wall, somewhere in between “slavery and freedom, man and woman”. Hedwig’s botched sex change is the moment at which she loses her maleness and becomes a person somewhere in between male and female. The closing image shows us Hedwig emotionally healed and whole, having found her other half within herself. It was essential to move through the central image because it shows us the moment of Hedwig’s division.
What changes in the landscape? The lights and projections change frequently.
What changes in the action? Hedwig and the Angry Inch moves from defiance to self-acceptance.
What doesn’t change? The Angry Inch don’t really change at all - they seem to be there mostly to accompany Hedwig and Yitzhak.
Hedwig and the Angry Inch asks the audience to empathize with Hedwig, to feel her emotions along with her.
Hedwig and the Angry Inch is a musical about self-acceptance.
Hedwig and the Angry Inch is a musical about searching for an other half and finding it within yourself.
Hedwig and the Angry Inch is a musical about Hedwig, an East German genderqueer woman who writes and performs glam rock and punk music. Growing up in East Berlin, Hedwig becomes obsessed with the idea that everyone has an “other half” somewhere in the world that will complete them. When she falls in love with an American solider, Hedwig undergoes a botched sex change operation in order to marry him and move to America, only for him to leave her. After her operation, Hedwig sees herself as divided between male and female. After she moves to Junction City, New Jersey, Hedwig trains a young man named Tommy Speck to be a rock star, only for him to also leave her when he discovers her botched sex change, eventually using her songs to become a famous musician. As Hedwig tells her life story over the course of the musical, she lets go of her pain and anger, and comes to realize that she is more than a woman or a man, and that she does not need another person to complete her.
One part of this lab gave me some trouble: the last section, where we’re supposed to have two force sensitive resistors controlling the brightness of two LEDs.
I was able to get the circuit and code working, but for some reason, whenever I squeezed one FSR, the resistance of the other adjacent FSR would also decrease by a small amount, allowing a small amount of voltage (in the range of 0.04V - 0.06V) to get through to the Arduino and turn on the corresponding LED.
I’m not sure why this is happening…The circuits that measure the resistance of the FSRs should be independent from one another, so it’s not clear to me why one would affect the other.
As part of our homework for week 2 of Physical Computing, I had to come up with an application for a switch or turn an everyday object into a switch. I chose to turn one of my mechanical pencils into a switch using conductive copper tape.
Honestly, I struggled with this assignment, and I don’t feel that my Cornell box reflects my emotional response to Aunt Dan and Lemon in a meaningful way. I tried to develop a coherent concept from the objects that I found, but I think that if I were to do this assignment again, I would approach it from the other way around - start with a concept and then try to find objects that fit.
What is space like? The space in Aunt Dan and Lemon is ephemeral. Scenes and figures emerge from and fade into the darkness as Lemon guides the audience through her memories. The play begins and ends in Lemon’s flat in London, and there are memories which take place in Oxford and the English countryside, but you could say that the space of the play is really the interior of Lemon’s mind.
What is time like? Time moves back and forth, jumping across many years at a time from one memory to the next. At some points, such as when Aunt Dan is telling a young Lemon stories about her university days at Oxford, time becomes nested, moving further into the past of Aunt Dan’s story, and then returning to the more recent past of Lemon’s memory. Strictly speaking, all of the scenes in the play take place sometime between the 1940s/1950s and the 1980s.
What is the climate like? The season and the weather varies a lot from memory to memory. In Lemon’s recollections of her childhood home, it is summer, and the air is “sticky and hot.” Later, in her mother’s memory of meeting Aunt Dan at Oxford, it is winter, and the light is gray and dim.
What is the mood? What is the tone? The mood of the play, going by its subject matter and themes, is serious. It explores the ways in which people justify violence and killing. The tone of the play is at times soft and reflective (“The light from the window - the purplish light of the dusk - would fall across her face.”), at others passionate and romantic (“…whose lipstick was the dreamiest, loveliest shade of rose”), at others violent (“And then these filthy, slimy worms, the little journalists, come along…”).
What is the pattern of sound? The play makes frequent use of long silences to punctuate monologues or conversation. “(Lemon drinks. A long silence.)“ “(The garden. A silence before Aunt Dan speaks.)“ “(After a long pause.)“ “(Aunt Dan is silent.)“
Is this a public world, or private? What are its class rules? This world is private and insular. Most of the characters (with the possible exception of Mindy) are middle/upper class British people and Americans.
In what patterns do figures arrange themselves? Lemon, as narrator, is presented in isolation. Aunt Dan is often paired with another character, either Lemon or her mother. In Aunt Dan’s memories of Oxford, the action revolves around Mindy, and all the other characters surround her.
How do figures appear? Most of the characters are presented in an exaggerated manner. Lemon’s mother and father are almost caricatures, as are Aunt Dan’s friends from Oxford. Aunt Dan and Lemon are, unsurprisingly, the most three-dimensional figures in the play.
How do figures dress? As far as I can tell, the characters’ clothing isn’t discussed very often, if at all. My guess would be they’re dressing in period-appropriate attire.
How do figures interact? Lemon, as the narrator, doesn’t interact directly with any of the other characters. Aunt Dan and the young Lemon’s interactions mostly consist of Aunt Dan telling Lemon stories about her life. Aunt Dan picks a fight with Lemon’s mother over whether the Vietnam War is justified, although Lemon’s mother tries to have a reasonable discussion. Lemon’s father berates Lemon’s mother for Lemon’s eating disorder.
Who has power on this planet? Lemon’s worldview is shaped by Aunt Dan’s stories and political ideologies, so you could say that Aunt Dan has power over Lemon as a sort of twisted mentor figure. It’s never really made clear why Aunt Dan chooses to have this relationship with Lemon, although late in the play, Lemon suggests that there might be an unspoken sexual attraction between the two of them.
What are the language habits? Lemon’s language is mostly a language of thoughts, logical, detached, and deliberate. “In other words, it was unpleasant to watch that pitiful roach scuttling around on my floor dying, but I can’t say that I really felt sad about it.” Aunt Dan’s language, by comparison, is emotional and passionate. “I mean, Lemon, you know, that Transfigured Night could just make you squeal, it’s just as if Arnold Schoenberg was inside your dress and running his hands over your entire body.”
- First image: “London. A dark room. A woman named Lemon, born in 1960. She sits in an armchair, weak and sick.“
- Last image: “The dark room, as at the beginning of the play.“
- Central image: Aunt Dan and Lemon’s mother in the garden, arguing about Kissinger and the Vietnam War.
- Why was it essential to move through the central image to get from the first to the last? The play begins and ends in the same scene, with Lemon explaining why she enjoys reading about the Nazis, that she believes compassion doesn’t really exist and that “polite” society is dependent on killing. The action of the play shows us where Lemon’s worldview comes from, how she internalized Aunt Dan’s beliefs about the necessity of violence.
What changes in the landscape? The setting moves from the inside of Lemon’s apartment in London, to Lemon’s childhood home, then to Andy’s flat in Oxford, then to Morley’s night club, then to Mindy’s apartment, then back to Lemon’s childhood home, then to Aunt Dan’s apartment, then finally back to Lemon’s apartment.
What changes in time? Time begins at the present, moves into the past of Lemon’s childhood, then moves further into the past of Aunt Dan’s memories, then returns to Lemon’s childhood, and finally returns to the present.
What changes in the action? The action of the play doesn’t really fit any of the progressions that Fuchs describes. The play begins and ends with the same scene, with Lemon unchanged as a character. The difference is that the audience now understands her better.
What doesn’t change? The adult Lemon, the narrator, is a fixed point throughout the play.
Aunt Dan and Lemon asks the audience to reflect on how fascist ideas are passed down from generation to generation, and to acknowledge that fascism still exists in our society today. The play makes this intention known by showing a natural progression from Aunt Dan’s idealization of Henry Kissinger to Lemon’s monologue about admiring the honesty of the Nazis and the necessity of killing.
Aunt Dan and Lemon is about the allure of fascism.
Aunt Dan and Lemon is about how fascist ideology can be passed down from generation to generation, even among people in our society who seem to be no different from us.
Aunt Dan and Lemon is about a British woman named Lemon with a difficult childhood who grows up idealizing her “Aunt” Dan, an American friend of her parents. Aunt Dan worships Henry Kissinger, defends U.S. military policy in the Vietnam War, and tells a young Lemon violent and sexually explicit stories about her wild youth at Oxford. As an adult, Lemon internalizes Aunt Dan’s worldview and becomes a fascist apologist, believing that compassion is a lie and admiring the “honesty” of the Nazis and killers in general.
Chris Crawford defines interaction as “a cyclic process in which two actors alternatively listen, think, and speak.” I think that that definition works well for physical interaction, except that I’d replace the terms “listen” and “speak” with “sense” and “respond”, respectively. Although Crawford uses “listen” and “speak” metaphorically, I think that “sense” and “respond” are a little clearer because they suggest a wide variety of inputs and outputs that translate physical phenomena into analog/digital electical signals and vice versa.
Some examples of physical sensing and responding:
- Distance (Ultrasound)
I think that Crawford’s thoughts about “high” vs. “low” interactivity are on point here. It’s not enough to just listen, think, and respond - each step has to be done well. Good physical interaction requires a work or piece of technology to:
- Sense accurately
- Process what it senses in an interesting or non-trivial way
- Respond in a way that is comprehensible and communicates meaning
Bret Victor’s comments about moving beyond visual interfaces are also relevant here. Good physical interaction should try to use other human senses as well, such as texture, temperature, hearing, etc. Good physical interaction should be, well, physical.
One of my favorite works that involves digital technology that would not be considered interactive is Julien Maire’s Digit, a performance piece that makes use of tiny, hidden printers to create the illusion that the artist is producing printed text simply by sliding his finger across a piece of paper. The printer system isn’t really interactive according to the definition above; it’s more of a tool that translates the artist’s movement into text.
Jürg Lehni’s drawing machines (and most drawing machines in general) are also examples of non-interactive digital technology. They translate images or text into physical motion - communication is one-way from human to machine.