Sep 11 2018

The Chilopod

By Max

So I went to Burning Man for the first time.   It was strange and wonderful and difficult and beautiful, often at the same time.   I was working on an art installation, the Chilopod (official facebook page).   It’s a two-story insect-like structure with lights all over it that reacts to its environment.  Also, there is a slide on the back.

I primarily worked on the software controls during the pre-build phase.   It was my first time using TouchDesigner, which is an amazingly flexible tool to create generative video, e.g. if you want to take inputs from the environment and create a responsive video content.  It turns out to be pretty easy to connect TouchDesigner to Arduino via either serial or via ethernet, which opens up some really interesting possibilities.  One of the drawbacks of the Arduino ecosystem is that the development boards aren’t generally beefy enough to do live video.  On the other hand, getting data out of a serial port and triggering something on the PC with it can be difficult without writing custom software.   So TouchDesigner is kind of an ideal tool for this, and I’m thinking a lot about what I can do with the new toolset.

Here is some early conceptual work showing breathing and heartbeat patterns (rendered in real time in Touchdesigner):

Same pattern, this shows how the heartbeat and breathing is composited in Touchdesigner:

Here’s an example of a simple pattern being driven by a wind sensor.   The graphical wind sensor panel, video, and sensor input are all being handled by TouchDesigner.  Pretty neat stuff:

Anyway, while I spent most of my pre-build time in front of a screen, once we were out there our problems were a lot more actual.   Like raising a 300lb insect leg into place in the middle of a dust storm.

Or rigging up a plastic bin and shopping bag as an impromptu dust collection system to avoid leaving sawdust all over the place (Burning Man is scrupulously Leave No Trace, including biodegradable matter).  It reminded me a lot of my time doing theater work, working against a deadline and solving unique and faintly ridiculous problems.  Also, it is the dirtiest I have ever been in my life:

Thanks for reading!



Apr 13 2018

I made a thing with TouchDesigner

By Max

TouchDesigner is a visual programming interface to make interactive video art, I guess?   I’ve been doing some work with it lately, for a larger-scale project I’m working on.    One of the first things I wanted to do was make TouchDesigner talk to Arduino, so that I can feed it inputs from hardware sensors.   I thought a short video demonstrating how that works would be useful, heeeere you go:

If you want the files I’m using, you can download them here, thanks for watching!



Mar 26 2018

Redwood Planter Boxes, the Sequel

By Max

We had a lot of pots taking up floor space on the deck in the new place, so I built these redwood planter boxes for our herb garden.  I’ve gotten much faster and more accurate with woodworking generally and dovetails especially then the last time I made one of these.  I’m now cutting out waste with a coping saw instead of chopping it out with a chisel, which is about 3x faster.   I’m also smarter about things like not trying to get the crummy construction-grade lumber I’m working with perfectly straight and true, and for these I used plastic inserts to hold the soil which greatly simplified the design and will be more durable I think.

I finished it with a couple coats of very thin shellac to try and get the shellac as far into the wood as possible, then with a layer of wood waterproofer over that, and a coat of furniture polish over the top of that.   Then it rained for a solid week (Mediterranean climate!) and the photos above were taken just after another shower.  I’m seeing some water get into the endgrain but that’s to be expected I guess.

The new setup gets us more space, while making the deck feel a little more enclosed.   The planters should get plenty of sun from the southern exposure, but it’s still San Francisco so probably no tomatoes.  But thus far I’ve planted the cilantro, which was harvested from last year’s crop.  I was worried that the seeds wouldn’t be viable because what do I know about any of this, but turns out they were very viable and I’m having to thin them pretty aggressively:

The dill just started to come up, they look like aliens:

The sage was a transplant from the old planter, but seems to be settling in:

Moments after taking this the spider went jumping  off the balcony on a stream of silk.  I guess he didn’t like the cell phone right up in his grill, and who can blame him?

After planing the sides, this is the quantity of shavings.  It’s really satisfying to make simple, beautiful objects like this.

Thanks for reading my dumb blog post about gardening!

May 12 2017

Let’s combine a cheap wireless doorbell with a century-old phone

By Max

We recently (ish) moved into a new place, a big old victorian in the Haight.   There was no doorbell for our unit, so we did what you do and bought whatever the first result was for ‘wireless doorbell’ on Amazon.   About the same time, the Rents were doing some spring cleaning and gave me the wall phone above, because I guess they didn’t need it anymore.  Which raises but does not answer the question of why they needed it in the first place.  So when I have a few drinks and buy random technological artifacts on eBay, there might be some precedent for that.  Anyway, the preset ringtones on the doorbell were pretty hideous, and I thought why not class it up and make the phone ring when someone presses the doorbell instead?

If you want the YouTube video version of this, that’s here.

The Phone: This is probably 1915 or so.  The case is oak, the metal parts are brass.  You would ‘dial’ by clicking the receiver hook up and down which would summon a human operator, who would connect your call for you.

In the upper compartment on the right is a hand crank you would use to generate the voltage to send your voice back to the phone company.  Unfortunately that dynamo part is long gone, but the hand crank is visible on the right side.  In the lower compartment, clockwise from bottom left, is the Arduino, the wireless receiver from the doorbell, the high voltage circuit, and some perfboard to tie everything together.

For the high voltage circuit, I found this circuit on the Sparkfun site, which they were nice enough to open-source.   There’s a boost converter that kicks the 5V up to about 55V, and an H-bridge that allows you to switch the direction of the voltage through the solenoid.  I built the circuit and it worked, although if I was doing it again I might have gone for something that did the full 90V–  The ring could be a little more musical, and I think that might be because the clapper doesn’t have enough oomph to strike the bell cleanly.  On the other hand, it’s plenty loud as it is.    Here’s the circuit:

I also wired up the handset piece to play a dialtone when you pick it up off the hook.   Which has a practical purpose in confirming the processor is up and running, but mainly for fun.

The Doorbell: I opened up the receiver unit.   I was expecting to have to kind of kludge together the entire doorbell with the ringer circuit, but I noticed that the RF part of the board is a separate unit and just soldered onto the main logic board (at top):

The receiver circuit appears to be a buyout, which is ideal assuming I can figure out what the communication protocol is.  I did a search for the IC number, PT4303, and found a datasheet which told me it’s just a heterodyne, i.e. it’s just amplifying the signal to be decoded elsewhere.  Also that the chip is 5V tolerant, which is very convenient as I wanted to run this whole thing off a USB charger.

I hooked the receiver up to the oscilloscope and started poking at the transmitter while pressing the doorbell switch.   And found a digital signal on one of the transmitter pins (yellow), which was also showing up on the receiver data line (blue).   Bingo:

On the left is random noise, but as soon as I hit that button there’s a repeated digital pattern.   The pattern is either long-short (0) or short-long (1), in my case as you can see above the code was 00010011110010000.

For power, I wanted to use the vintage-style cloth-wrapped cable, but I also wanted to power it off USB.   I grafted a USB cable onto it and used the charger for my prior phone.

The Code: I used this library (that link does a good job of explaining the signal), although my timings were different so I guess there are slight differences in model.   If you want my arduino sketch (which includes the code to ring the phone and also generate a dial tone signal when the receiver is up) and also my Eagle file that’s here.

Here’s a video walkthrough I did.   Sorry if the camera work/narration is not the best.

If you enjoyed this or found it useful, be sure to leave a comment below.  Thanks for reading!

Sep 4 2016

Parklet Design Assignment

By Max


Another project I did for my Arch 134 class.  The assignment was: Design a parklet!


I started with the Tenderloin neighborhood in San Francisco where I lived at the time (life has changed drastically in the last two years!).  Typically parklets provide some kind of public amenity, an eddy to step out of the stream of pedestrian traffic.  If you put a parklet on Eddy street it would immediately become a venue for people to do all the things that you don’t want them to do, but it’s not like the neighborhood doesn’t have unmet needs.


So, I get it.  We don’t want to pay for public restrooms for homeless people.  In addition to the considerable expense associated with operating a high-traffic public restroom, it requires constant vigilance to make sure the facility is actually being used as a place to do your business, not your “business.”  Actually I’m not sure which usage would get the euphemism quotes, but anyway my point is, whether you want to pay for this or not, you’re going to pay for restrooms for homeless people.

Have you been to the main San Francisco Library at Hyde and Grove?  It’s a nice enough library, in an inoffensive 90’s postmodern way.  It’s also the only available public restroom in a 1/4 mile radius, and so the restrooms are always packed with people who don’t have another option, and have to constantly patrolled by security officers to keep the chaos to a low roar.  The streets east of Larkin and south of Geary are full of evidence that this facility isn’t nearly enough to meet demand.  So I decided to design a parklet around public restrooms.


I placed the parklet between the current day-use public restrooms at the Public Library, and the current after-hours restroom, the Lawrence Halprin-designed fountain in the middle of U.N. Plaza.  I like that this location breaks up the formal scenic view between U.N. Plaza and City Hall in a somewhat obnoxious way.

Map Capture with markups

Programming and Design

In addition to providing public restrooms, I wanted to provide public showers.  I included a micro-retail space as well, since I figured that there would have to be some kind of revenue-generating function as well to keep the whole thing going.  Using shipping containers would make it easy to set up and move.


Access to shower/toilets are via facebook check-in.  I think that sets a balance between the desire for these facilities to be available for all (facebook accounts can be created for free at the adjacent library), and the need to control access to prevent non-sanctioned use.

floor 1

The first floor incorporates three toilets, the stairs to the second level, and the handwashing station.  I was imagining the back wall behind the stairs as some kind of mesh or grillework, to keep the space open and ventilated.

floor 2

The second level is showers, and would be at about eye level to the adjacent statue of Simón Bolívar, and would have nice views on City Hall.    Also included on this level is a micro-retail, to provide some income to pay for operating costs.  Placing all of this on the second level allows access control after hours, versus the restrooms that are envisioned as 24-hour facilities.


This was a class project done over a weekend, so think of it as a sketch rather than a 100% build-able proposal.  But, if you’ve walked by the Tenderloin Pit Stop on Ellis St, you can see that this sort of thing can work.  Similarly, Lava Mae is doing fantastic work upcycling retired transit buses to mobile shower units.  It’s a simple way to improve the quality of life for everyone that shares the city.