Category Archives: Projects

Opposable Thumbs Episode 7: Homemade Chemicals

Opposable Thumbs is a podcast where Rob Ray and I solve a different design challenge every two weeks. Each episode features a guest with a different creative background, and each guest picks the challenge for the next episode. You can listen to all of our episodes here.


Homemade Chemicals! For this episode I revisited the idea of etching my own circuit boards, which I’d previously attempted (and failed). I watched/read a lot of cool tutorials online, then settled on this one. Sylvia’s Super Awesome Mini Maker Show was also a strong influence. Man, I can’t wait to get my kid into that kind of next-level nerdery…

I think my previous failure was due to old chemicals. All this ran about $25, but you could probably make it cheaper depending on what’s laying around the shop. I also made a little more volume this time: 2 shots acid and 4 shots peroxide (though that may be a glass votive candle holder, YMMV). I researched my gloves and bucket composition to make sure I didn’t create a Breaking Bad situation. I also wore wraparound goggles and pants, though I did wear short sleeves – nobody’s perfect. I suppose I should put a disclaimer here: try this stuff at your own risk, do your homework, and be careful! Muriatic acid is no joke.


This process etched a credit card sized board in about 10 minutes. The etch moves faster as time goes by, and you could almost watch the last 10% dissolve in real time. The solution is supposed to keep indefinitely, and can be refreshed with more acid and/or peroxide. See the link above for details.

As always, please listen to the show and send us your feedback.

Opposable Thumbs Episode 6: Whiteness

Opposable Thumbs is a podcast where Rob Ray and I solve a different design challenge every two weeks. Each episode features a guest with a different creative background, and each guest picks the challenge for the next episode. You can listen to all of our episodes here.


Whiteness! After much soul-searching, I decided that I was not going to make an object in two weeks that claimed to tackle this thorny issue in a meaningful way. Instead, I decided to make a purposefully goofy widget that could aid in my personal engagement with the subject. Along with my trusty fidget spinner, I read some articles that intersected with Whiteness, including Ta-Nehisi Coates’ The Case for Reparations. Dude, the Atlantic has been killing it; support long-form journalism today! Also read My Family’s Slave while you’re at it.

Rob and I dig deep on this one! Please listen and send us your feedback.

Opposable Thumbs Episode 5: Huong Ngo / I Don’t Care You Pick

Opposable Thumbs is a podcast where Rob Ray and I solve a different design challenge every two weeks. Each episode features a guest with a different creative background, and each guest picks the challenge for the next episode. You can listen to all of our episodes here.

I really wrestled with the episode 5 challenge: I Don’t Care, You Pick. My first impulse was to move away from coding, given that I’ve gone that route for each of the last four Opposable Thumbs projects. With this prohibition in mind, I set about reworking Brian Eno’s Oblique Strategies into a set of more applied/practical suggestions like:

  1. Try to end the day on a solution rather than a problem.
  2. If you think something might be hot, test it with the back of your hand rather than your palm.
  3. If you have a good idea, it’s probably already been done. This is no reason not to move forward.

I liked where that was starting to go, but I still felt unsatisfied. After all, where were the things? At the last moment, I switched gears and converted an old CNC pen mount into an etching needle attachment. I unearthed an old Processing sketch that made semi-random visuals, then scratched the output of this code into a copper plate with the mill. With help from the excellent staff in the Columbia College print shop (thanks Megan/Chris), I pulled the image above.

Opposable Thumbs Episode 4: Nick Bontrager/Stand Up Comedy

Meghan Trainor (no not that one) pitched us a curveball in Episode 3 with the “stand up comedy” challenge. Nick Bontranger was up to the task, and you can listen to his response here.

It occurred to me that I could enter this challenge in a completely straight-forward manner: by writing a traditional comedy set. This idea was immediately displaced by the urge to do something techie, so I started writing a script that could pull down humorous material from the web. Reddit seemed like a good place to look, given that it has a metric crapload of commentary to draw from (the following assumes you’re working in OSX).

  1. Make a new reddit account
  2. Follow these steps to create a script-type application (just follow the “first steps” section).
  3. Open your terminal and easy_install pip  (may need sudo)
  4. Now create a virtual Python environment for your project and activate it. Do this so random updates don’t tank your script. Take special note of source venv/bin/activate , which will put you in virtual mode for the next steps.
  5. pip install praw
  6. python
  7. This script looks for comments that include the words “tragedy” or “time” and prints them in the terminal.
  8. For the final output I installed Soundflower, which allowed me to record straight off the sound card. I then had the OSX accessibility assistants read the text aloud and laugh at it robotically.
  9. See python code below:

Opposable Thumbs Episode 3: Found Electronics

Only 90's kids will understand!

Only 90’s kids will understand! via

Listen to Episode 3 here.

At the suggestion of my main man Audrey Peiper, I based this project on a Girl Talk telephone handset that I had laying around the studio. I fear this will only embolden my mother-in-law, who exploits my penchant for hoarding electronics ruthlessly.

Given the ridiculously gendered nature of my starting point, I decided to reengineer the phone’s components to make a positive statement about women and technology. This got me thinking about how some of the original “computers” were women, back when the term described people who performed mathematical calculations. Ada Lovelace is another great example of a woman who contributed significantly to early computing with her work on Babbage’s Analytical Engine.

With these ideas in mind, I desoldered all of the components from my handset. This yielded a pile of simple parts, artificially limiting the potential complexity of my project. Working within this structure, I soon settled on the concept of the multivibrator, a simple circuit that can be switched between two states. The first multivibrators were astable, switching back and forth between states at a regular interval. Mono and bistable vibrators came next, and these circuits formed the foundation of modern computer memory (due to their ability to “remember” one bit worth of information). I didn’t quite have enough components to make my vibrator stable, so here’s a demo of an astable multivibrator or “flip-flop.”

From a 2017 perspective, this circuit is not that impressive! I dig it though, because it shows what complexity you can reach in the absence of integrated circuits. To change the timing of the circuit, you can substitute different capacitor values – larger Farad ratings will take longer to drain, resulting in a slower oscillation. No coding here, just good ole’ math (or blind experimentation). See this page for the diagram I followed and build your own.

Full disclosure: The red LED didn’t come from the phone. There, I said it!


Opposable Thumbs Episode 2: Dungeons and Dragons Dice

For the second Opposable Thumbs challenge, I started researching ancient games of chance. It seems that the original dice where the knucklebones taken from livestock like sheep or goats. While you can order the real thing online, I opted to 3D print an open source set because it was quicker. Then I made a wooden box, strapped a piezo sensor to the back, and taught an Arduino to interpret these vibrations numerically. This information is shared with a Processing app, where the numbers are mapped onto various numerical ranges (1-4, 1-6, 1-8, etc.). The system is currently set up for the 7 most common DnD dice, but this is easy to change in the code.

I think the next step for the project is to hook up with the roll20 API. This website allows players to meet in an online space that supports maps, character sheets, and the like. Knucklebones 1.0 would allow such virtual games to retain some tactility by requiring physical rolls, though the objects in question need not be actual dice.




Opposable Thumbs Episode 1

The excellent Rob Ray and I have started a podcast called Opposable Thumbs. I used to organize art events with Rob in Chicago some years ago, and I’ve been itching to work with him again ever since he escaped to LA.

OT is a biweekly creative exercise where Rob and I invite a guest to set some sort of design challenge. Next, the three of us each make something based on that prompt, then Skype in to talk about our successes and failures. The first episode is out now! Here’s a preview of my project:


Prompt: Paper Clip & 2×4

In this episode I create a diegetic prototype that recruits material “flaws” (such as the knot above) to act as touch sensors. The paperclip or other wire is embedded in the wood and attached to two pins on the Arduino. Add a 1M resistor or greater and use the source code below. Right now we’re just blinking an LED, but that’s how all great things start… Please download, remix, and send me photos or video of your implementation!


Sterling Silver at Shapeways

I’m working on a new version of Controlled Feeding Status that will be cast in sterling silver! First test “print” just arrived and is looking hot. Next up: soldering and refinishing.

Seeed GPRS v2 in Hong Kong?

It’s the classic new media problem: you’ve got a cool show abroad, but will all your technology still work over there? I need to determine whether this board and this SIM card will be compatible in Hong Kong. This page suggests that 2G (a limit presented by the board) is still available in Hong Kong, and that the 900 band is still active. I suppose my fallback will be purchasing SIM cards when I arrive, but I’d like to avoid that. It may be cheaper, however, so maybe I’ll try both.

ThreeYearContract accepted @ ISEA Hong Kong


The title says it all! Track the project progress here if you want all the code/schematics. Here’s more info about the show.