Physical Computing — ITP

I’m auditing Intro to Physical Computing at ITP, and this is my attempt at keeping a weekly blog like the students do. Warning: this will mostly be notes and streams of consciousnesses and completely unedited.

Week 1

I missed the first class because I was traveling into NYC from SF that evening. But I did just catch up on the reading.

First, The Art of Interactive Design, chapters 1 & 2. The first chapter defined interactivity as a cyclic process with two actors that alternate listening, thinking, and speaking.

It was very opinionated. What stood out to me most was the author’s claim at the end of chapter 2, that a well designed interactive product must be able to do all three — listening, thinking, speaking — well. If it only does two of them strongly but fails at the third, then it’s not enough.

I’m trying to think of an example of this. Looking up the author Chris Crawford, he is a computer game designer. So for a video game, I can imagine that the game listens for the player’s keyboard input, and “speaks” (responds) back with some change to the game. But I wonder what the thinking part is. Is it as simple as that there’s a pre-programmed response, and so the thinking was done when it was first programmed? Or should something that is truly interactive, “think” on the fly, and generate a different outcome every time? (I’ve heard of “generative video games”, where the levels are to my understanding, generated on the fly — with Crawford’s strict definition of interactivity, would those games be the only types of games we can call interactive?)

I don’t think I’d follow this definition strictly in my own work, but it’s certainly interesting to keep in mind. (Because, if I have a data-driven visual tool where I can filter or aggregate, is that not interactive? Or does that still lack “thinking”?)

The second reading was Bret Victor’s Brief Rant on the Future of Interaction Design. I still remember reading it years ago, before I even knew who Bret Victor was. I remember being deeply inspired; it was one of the readings that made me start considering work outside of the screen (I was deeply invested in software engineering back then), that eventually led to my current goal of making something physical.

It was just as great of a read this time around.

Week 2

We learned about electricity this week.

First, the components. The three minimum components I need to make a circuit is a power source, a load (a light bulb, an LED, a fan, a buzzer, a motor, etc.), and the wires. I have to ensure continuity with the way that the three components are laid out, so that the electrical energy can always flow. The energy always flows from highest electrical potential to lowest, from positive/plus to negative/ground.

The three properties are the potential, resistance (load), and current. The analogy was a kitchen sink; the height of the water is the potential, the resistance is if there’s a pinch in the pipes that reduces the flow of water, and the current is the drips of water. (We were told that the analogy breaks pretty easily, so don’t extend it too far beyond that.

Notes from class: schematic for circuits (left), and kitchen sink analogy for potential, resistance, and current (right).

Our lab and homework assignment was to create a circuit with a breadboard, an LED, and a switch, and to get creative with the switch.

Red is usually used to indicate plus, and black is ground. Sketch of where breadboards are connected (left), and photo of LED bc apparently the order you plug it into matters.

So I first wired the breadboard, using the arduino as a power source that will (later on) be connected to my laptop. I connected the arduino’s plus and ground to the left of the breadboard, then ran another set of wires at the bottom to connect the left and the right (not needed for this lab, but apparently handy for future).

I then stuck an LED in the middle, connected the LED’s plus side to breadboard’s plus with a resistor and the ground with a wire. The resistor was needed because the arduino power source has a potential of 5V, and the LED has a much lower resistance. So to “use up” the rest of the electrical energy and keep from potentially short circuiting, I need a resistor; this one is apparently 220 ohm’s.

A switch can either be open (off) or closed (on) by default, and momentary or continuous. I decided to use two quarters as my switch (not sure what life metaphor this may be), which meant that they were by default an open and continuous switch. I replaced the black wire going from LED to breadboard with a longer black wire taped to a quarter, than used another black wire to connect another quarter to the breadboard’s ground.

I had a LOT of fun using the wire cutter (not pictured), but unfortunately didn’t realize that I should have been using a multimeter to measure the volts and ohms and amps. If I had, I think I would have been able to internalize Ohm’s Law (V = R * I) a lot better.

I also wish I had more time to think about this one, so that I could come up with something more creative. My goal for next week is to come up with a goal for the semester, and use each lab and homework assignment to hopefully get closer to that end goal.

Week 4

This week we learned about analog outputs, and learned to use a servo. I kept on wondering what I could do with a servo arm that goes between 0 and 180 degrees and by end of class my mind had somehow landed on a drawing machine.

My idea was to put an extended arm on the servo, and a marker on the extended arm. And because I wanted more movement then just one arm and a marker drawing a semi-circle, I thought of having two servos and two arms with the marker in the middle (sketch on left).

I got a foam core board, cut thin pieces strips out of it, and drilled some holes (my first time using a hand drill!) to make an extended arm. My husband made a good point that I could have more than one marker (!) so I stuck two calligraphy pens through, one on each arm.

In my first attempt, I had only one servo, so I attached one arm to the servo and tried to control the other arm myself. (I thought it’d be kinda cool to have a human-robot interaction moment, inspired by Sougwen Chung’s #drawingwithdoug) but alas it didn’t turn out quite well and (I might have accidentally vandalized the table at one point):

Yeseul Song super kindly lent me a second servo, and I was able to get something quite nice going. The two servos had a sort of bumbling amble going, where I’d start them as far apart as possible but they’d end up close to each other (they fall over together at the end in the video):

They were so cute, I call them my Randomly Bumbling Drawing Machine (rabudrama for short).

Here are the “artworks” they bumbled and ambled and created: