w6 motors hw journey continues

So I woke up bright and early this morning to make a run to my local hardware store, which has a huge selection of screws. I brought the motor mount with me, but it turns out they didn’t have the appropriate nuts or screws for the job. Instead, the man working there handed me a bag of nuts and screws that would never have fit. I scoured around for a while and chose instead two of the smallest wood screws I could find:

I blame sleep-deprivation for what happened next:

Luckily, Azalea was there to advise me to drill pilot holes first, then screw them in with a screw driver. It worked brilliantly (considering the circumstances):

Not ideal, but surprisingly snug anyway. Sorry, Ben!

I cut down some wood the night before, and glued it all together this morning. I’ll replace the placeholder wire with the mobile once it’s sufficiently dry. Here’s hoping it won’t topple over…

Soo the top of the “enclosure” shifted while it was drying, so the motor is slanted 🙁

fab w6 hw: mounting motors

For homework this week, I decided to add a motor to my 2-materials homework from last week. Being neurotic about aesthetics, my first move was to iterate on its design. It’s still not great, but getting there:

I showed up with this to office hours, and Ben was basically like, why haven’t you started on the actual assignment? Fair question. The 10 rpm motor I ordered off Amazon was late, and I had totally forgotten to buy a mount—admittedly, the entire point of the assignment. I strangely figured I could just drill a hole in some wood to press fit the motor.

Ben also pointed out that the coupler I stole from him during class wouldn’t fit on my motor. So he kindly lent me both a motor—similar to what I had ordered—and the mount itself. The 2mm to 3mm coupler, I would have to go to Tinkersphere for.

Of course, the coupler I needed was the only one sold out at Tinkersphere. So I borrowed one from Ridwan, despite it still being the wrong size. He also lent me a dowel that fit it, so I uh, did something I’m not proud of:

Yeah, I drilled a wire-sized hole into the dowel. It was Wednesday evening at that point and I was desperate! Especially bad was that at that point, all the hardware stores were closed, and I couldn’t find any appropriate screws for the mount, so that part would have to wait until the morning.

The next step was to put together the circuit. I ordered a 6V motor, so Ben suggested I use a voltage regulator. Mind you, I’ve never used neither a motor nor a voltage regulator, so it was definitely a learning experience.

post-break work

Barak ebay-ed two additional Mindflex headsets, and we tore down three of our four. Our plan was to create a new headset around a pair of noise-cancelling headphones for proper binaural beat entrainment. This meant we had to replace all of the leads on the Neurosky chip with longer silicon wires. This also meant we needed professional help, because the chips were tinier than our soldering skills were questionable.

Luckily, my father is an electrical engineer, so I flew our Neurosky chips home with me over Thanksgiving break and put him to work:

When I returned to NY, our chips were ready to go (with shiny new copper tape electrodes):

Barak came back with cheap headphones, the speakers from which we would install in the shooting range earmuffs we bought off Amazon.

For ICM playtesting that week, I created p5 sketches that—gradually for four minutes— pulsed binaural beats and a flashing background according to two states: relaxed mode at 4hz, and focused mode at 40hz. I had users wear the headphones and an EEG device, close their eyes, and face the flashing screen:

The video below shows a relaxed mode session, as well as the corresponding brain activity of the user. As we predicted, the 4hz entrainment from the p5 sketch seems to encourage ~4z brain waves (ie delta/theta frequency bands):

So that was pretty exciting!

We had also decided to incorporate a heart rate sensor, so that the tempo of the eventual entrainment music could sync to it. Here’s Barak’s clever serial-monitor-visualization of his heart rate:


The fact that the user would enter a dome made it necessary for the headset to be wireless. We purchased a Node MCU for the task, which meant the data would be sent over wifi instead of a serial port. In order to securely fasten the Node MCU to the Neurosky chip, we 3d-printed a little mount:

After making good progress on the headset, it was time to start on the geodesic dome. We purchased second-hand Hubs from a guy in Canada, as well as pretty much every single 5/8″ dowel from Home Depot. It was a big job, so we enlisted some help from my ever-helpful boyfriend:

And then it was off to Spandex World to get some miliskin for projecting on:

For the audio/visual entrainment piece, Barak used a combination of Ableton, an audio synthesizer, and Lumen, a visual synthesizer. Ableton receives heart rate information from our sensor over a midi port, which influences the tempo of the audio, and Lumen receives midi information from Ableton, which influences the frequency of the visuals. Here’s Barak playing with the different templates:


The actual colors would be red and blue for focused and relaxed mode, respectively. According to this paper, these colors encourage the frequency bands (beta/gamma and delta/theta, respectively) that we were targeting.

Yes, we realized covering the dome from the outside looked a little shabby, so we decided, on Ben Light’s suggestion, to use grommets:

More to come on dome development!

The last component was the olfactory entrainment. According to this paper, rosemary and lavender would encourage beta/gamma and delta/theta bands, respectively. We purchased $10 diffusers off Amazon to hack, as well as rosemary and lavender essential oils. Wiring up this circuit was a bit of a mindfuck for mysterious reasons we can’t even explain, but ultimately we ended up using transistors so that only the appropriate diffuser would turn on after the user chose their desired state:

Also notable is that we used our first rotary switch:

But after all that work (and acrylic), we ultimately decided to only go with the relaxed mode—it made more sense in context of the Winter Show. I mean, who would choose to become more alert during such an intensely stimulating environment?

Lastly, here’s a screenshot of the EEG visualization I’m working on for the show:

The canvas expands as the data streams in, which will be saved as an image at the end of each session. There’s also an option to start a new session, which will empty all arrays as well as signal the processing sketch to start over.

More soon!

So it begins

Where did I get the chutzpah to even consider making my own EEG device? While rummaging around on the internet, I found an 2010 blog post by an ITP alum who hacked the Mindflex—a game by Mattel—because the data-parsing chip was by Neurosky, a brand I recognized while window-shopping for consumer-grade EEG devices. I had ordered a couple of these Mindflex headsets off eBay and was hoarding them in my locker until I felt comfortable enough with my pcomp-ing abilities to break them open.

Luckily, I’d been able to rope the brilliant Barak Chamo onto this project, so it basically felt like I could do anything. On our first official team meeting, we broke open the packages:





And then it was time to work on disassembly. We wanted to go further with the deconstruction than our ITP predecessor, and found guidance in this teardown.

We couldn’t believe how comically simple this headset was, particularly this sad excuse for an electrode:

But this realization was as empowering as it was hilarious. Obviously, we could do better than a piece of conductive fabric.

Emboldened, we took the teardown a step further by completely desoldering the Neurosky chip from the Mindflex’s microcontroller.





And by some miracle, it still worked! We were able to get serial data from the naked chip. So I got to work on the p5 visualization:


w5 materials hw

I went to Metalliferous this week to search for supplies to make a mobile, and really loved combing through their wares. I purchased three 1/16″ brass rods, one 3/32″ hollow brass rod, some circular links (I’ve already forgotten what the staff said it was called), three little flat brass circles, and some stone beads. I was also looking for a thin chain, but surprisingly this jewelry supply store had no such thing.

I figured vaguely that the shop would have some wire cutters, and after much digging I found something that worked.

The hollow rods reasonably closed up after I cut them (even on the bandsaw), and so Barak devised a clever trick with my small screw driver to open them up again. It did create some sharp edges though:

I had the vague idea of making some kind of dangly, abstract sun sculpture, and so used these hollow brass rods to secure the solid wire in a loop:

(As for the beads, I was hoping to create a lunar orbit as well, but couldn’t think of a way of incorporating them.)

I wasn’t sure where to get a small piece of nice hardwood (and admittedly did not have much time this week to research), so I took some wood I already had and experimented with random stain and finish, with somewhat disgusting results:

The hardest part was stringing it all up. Since I couldn’t find a thin chain, I used some thread, which ended up being way too thin, fragile, and nearly impossible to work with. They also fell straight through my brass links, so I ended up tying them directly on my rings:

Not in love with the final result, but I’ll rework the design with better materials later. Ben, do you have any idea what I could use instead of string? Maybe fishing wire?

fab w4 hw: enclosures

This enclosures assignment was pretty good timing, as I needed something to bring for play-testing in ICM. I’ve been extremely wishy-washy on what the enclosure should look like, but I knew what components needed to be included, so it was enough to get to work with this renewable resource:

The best part about these (aside from being free) is that they’re literally box templates, so I just adjusted the dimensions to suit my needs, ie two essential oil diffusers and one Arduino:

My box ended up being 11″ x 4.25″ x 5.5″. I added little compartments to hold the diffusers in place, then laser-cut a lid for it. This is what I brought to play-testing:

Of course, finding a box with those exact dimensions wouldn’t be as easy as stealing from the US Postal Service, let alone finding one that could also either be machined cleanly or laser-cut safely. I had this cable organizer on my nightstand which was devastatingly close:

But after hours of scouring the web for a better fit (plus a false alarm at Muji), this turned out to be the best option. The cut-outs at the bottom meant that I didn’t have to worry about machining it at all.

The box is a little short, but better that than water vapor getting trapped inside and condensing all over the electronics. Plus, the extrusions will be less noticeable against white acrylic, which the lid will eventually be cut from.

The cardboard lids have flaps that fit into the box and keep it in place, but for the final I plan on lining the inner walls of the box with a layer of cardboard that the acrylic top could sit on.

pcomp help session notes

Playing sound with Arduino without a mp3 shield:

  1. Another device can access your local host as long as they’re on the same wifi network
  2. IP address, then path to the file
  3. can play music this way (through p5) without a shield!! (functionality is through p5)

fab w3 hw: laser cutting

I’ve laser cut for projects before, so for homework I wanted to run some tests on the laser cutter’s capabilities. But first…

…I needed to laser cut this for my bathroom faucets. I tried sanding the acrylic down for that frosted look, but it came out looking a little scratch-y instead.

Plus, something easy if all else fails:


… except this tiny 3×5″ template (from Thingiverse) took 10 minutes, and needed 3 passes before it actually cut through the acrylic. Luckily, I booked 3 hours on Monday (which ended up only being about 2.5 hours, since the person before me was struggling), so I had plenty of time to play around.

What I really wanted to know was how well the laser cutter would engrave raster images, because I’d only ever used vector paths. I heard that bitmap images were ideal, but wanted to see for myself. Here’s a test with both a bitmap tif and grayscale tif:

Both came out with a kind of moire pattern, but it was more pronounced in the greyscale tif (bottom). Unhappy with how faint the engraving was, I went for more passes:

Until it started to look a bit goopy…

My last test was with living hinges—I was so curious about them. Unfortunately…

This wood kept catching on fire! I adjusted the settings to prevent this, but even after a solid hour of passes, it was never able to cut through the wood (which was only 1/4″ thick).

The calendar was booked up by then, but thankfully I had booked another hour for Wednesday, since I knew I was going to need it. Of course, it ended up only being 45 minutes because the person ahead of me was struggling.

I wanted to try cutting the “live hinge” on cardboard. Sadly, halfway through the second pass, the board shifted—I’d forgotten to tape it down.

It ended up not mattering in the end, because the live hinge was totally shredded up:

But at least I have my spirograph:

Which apparently I am incapable of using…

Laser cutting

Laser cutter:

  • Test engraving/cutting settings with small squares first
  • Do not alter frequency setting
  • Speed can be adjusted
  • dpi is set in printer setup
  • cut in sections; the laser gets weaker the further it gets from the origin