I’ve been pecking away at Radian again. I burnt myself out building the object system last winter, and haven’t touched the project in six or seven months. It’s still been ticking away in the back of my head, though, and during a plane flight a couple weeks ago I discovered that I am ready to dig in once again. I hope to reign my enthusiasm back a little this time around – this kind of work needs to be done at a calm, steady pace, with plenty of time to think things over.

I haven’t added any new capabilities to the language yet, but there have been plenty of loose ends to clean up, and in sorting them out I have been refreshing my memory of the architecture and the work yet to be done. This is a project which could keep me busy forever, of course, but I’m actually encouraged to see how much is already there.

Suppliers of various enclosures for electronic equipment:
OKW – wide variety, mostly plastic, lots of handhelds and a fair number of desktop-type console boxes
Hammond Manufacturing – industrial focus, wide array of plain metal and plastic boxes, more functional than pretty; they have some nice steel/aluminum + walnut boxes though
Protocase – custom metal boxes, only a handful of styles but they will make them to any dimensions, and will do custom panels and silkscreening
Bud Industries – also industrially focused, functional parts but not particularly pretty

Anatomy of a Typical Phone Conversation. No, really. It’s awesome, and not in some cheesy making-fun-of-pop-culture kind of way.

I’ve been playing Bejeweled on my phone lately, and while on the way to work this morning I had an idea: one of these 8×8 RGB LED matrix displays would be a great interface for a touch-sensitive standalone version of the game. You could use the LEDs themselves as touch sensors, multiplexing them as both inputs and outputs. Pack it up in a sleek little aluminum shell and you’ve got a fun little party toy.

I’m not going to build this.

Interesting discussion on StackExchange: What’s new in persistent/immutable functional data structures since Okasaki’s classic book Purely Functional Data Structures? Turns out there are a number of interesting systems that have been published since then.

Maybe I should take another crack at that functional version of the left-leaning red-black tree I was working on in January.

Worldchanging.com is hosting an event called Future City on the Friday after next (October 1st), featuring the mayors of Seattle and Portland. It’s going to be a big fancy thing with food and beer and art, and among the art will be Eva’s flowers, and thus, my bloom lights; which is the whole point of this message. If you want to see the finished pieces in action, and you feel like discussion about Cascadia, climate change, and government policy would be a fascinating way to spend an evening, maybe you should think about coming along!

How to make your own laser using parts available at any hardware store. Yes, seriously: the lasing medium is plain old air at ambient pressure, ionized by an arc discharge between two long parallel electrodes.

Structure Synth is a cross-platform application for generating 3D structures by specifying a design grammar. Even simple systems may generate surprising and complex structures. The design grammar approach was originally devised by Chris Coyne (for a 2D implementation see the popular Context Free Art).

Structure Synth offers a graphical environment with multiple tabs, syntax highlighting, and OpenGL preview. Integration with third-party renderers (such as Sunflow and POV-Ray) is possible using a flexible template based export system.

I have had an idea kicking around in my head for years about a 3D version of Starfish based on similar principles. The process of building the rendering engine always seemed daunting. Perhaps I could base the generation algorithm on this system…

After some emails back and forth with our real estate agent, Ava and I were finally ready to send in our offer paperwork last Saturday. Then I happened to pull up the page for the house: to our shock, the house had been delisted! Not sold, just… removed. Very strange. We talked to our agent again; he speculated that they might have decided to rent it out, and said we should probably just send in the offer anyway.

Several days pass. Silence. They neither accepted, rejected, nor countered our offer. This, our agent tells us, is very strange. Our hopes sink. What could possibly be going on?

Well, now we know: Real-estate brokerage suspended by regulators. Turns out the selling agency has been involved in all kinds of fraud, and the listing for the house we want was pulled off MLS along with all of their listings. Since then, the owner has put the house back on the market – at an even lower price! – and we’re about ready for another try at making an offer on it.

Sylvia’s Super Awesome Maker Show is always energetic and adorable. The latest episode is all about Arduino, with a couple of easy-to-build projects that make light and noise.

I have had this idea kicking around idea for a percussion synthesizer device, probably based on an STM32F103. Today I found a document on the ST web site explaining how to generate 12-bit stereo using the built-in DACs. Super simple – all you need is a pair of RC filters and an audio jack!

There is something a little perverse about embedding what ends up being a softsynth into a piece of hardware, but I really like having a dedicated UI for my audio gear, and I like not having to deal with all the complexity and uncertainty of a computer.

How to program an MSP430 from Linux, using TI’s Launchpad board (the one that costs $4.30 and includes a USB interface). Looks like it is generally a big nuisance. I wonder how much work it would be to rig up an Arduino-style interface for the LaunchPad that does all the necessary mspgcc manipulation?

The Mesh Potato project appears to have a lot in common with my walkie-textie concept. It’s based on a completely different set of technologies and user interactions, but the end result is similar: a free, open, decentralized telecommunications mechanism. I wonder if it would be possible to make the systems cross-compatible?

I really overcommitted myself this summer. I did finally manage to get the last of six bloom lights working just before Eva had to leave for Burning Man. I don’t have any pictures but hopefully there will be some good ones when everyone comes back from the burn. I also spent an evening helping Chris with his group’s firefly costumes, assembling four controllers with light sensors and high-powered LEDs; the idea is that each light will flash at some adjustable interval, and that the controllers will watch for other flashes and try to stay in sync. This of course means that they will pick up on any source of flashing light, of which there will be many on the playa. Add on half a dozen minor errands I’ve run for other friends, and I’ve ended up doing a surprising amount of Burning Man prep considering the fact that I am not even going this year. Oh, well. I’m working down my list of commitments and trying to refrain from making any new ones for a while. I need a break – and a few long nights of sleep.

Ava and I looked at a couple more houses yesterday. One was a 1900 construction just around the corner from John & Holly; it was in surprisingly good shape, had a nice big yard, and would have needed very little work. Three bedrooms upstairs, a nice big kitchen (built as an addition to the original house!), even a parking space. The other place was a wreck – priced accordingly, to be sure, but it would have been months of work, and it really wasn’t what we were looking for.

I think we’re about ready to make an offer: despite being on a busy street and having no yard, we really like the house on 23rd. It’s a good price, a good project, and a good location.

Work is going OK. It has been tough keeping everything in the air since I have been burning so much energy on other projects, but that is settling down, and I’ve done some good work in the last couple of days. I’m working on a design and estimate for the next phase of the project I just finished; not a big thing but it has some interesting challenges.

Ava and I got married one year ago today. We took a motorcycle trip down the Pacific coast, hung a left at Crescent City, rolled into Reno, got a wedding license, and headed over to the Arch of Reno Wedding Chapel about twenty minutes before they closed for the day. Tonight we’re going to go celebrate the milestone at El Gaucho.

She’s the one I want, and I’m glad we have each other.

I had an unexpectedly adventurous night and ended up sleeping til noon this morning. So far I have spent this scorchingly hot summer afternoon sitting at my desk; my sister MJ is working on a paper for a law journal, and I’m trying to help her out with the final editing work. Truth be told I’m almost always happier indoors with a fan when the weather is this hot; I’ll almost certainly perk up when sunset approaches.

I finally got around to listing my FJ600 on craigslist. I haven’t gotten any responses yet, though, which is disappointing – it’s such a pretty little bike! Oh, well, I’ll keep at it.

Ava and I are thinking seriously about making an offer on a house. We looked at the place a couple of weeks ago – it’s definitely a project, but one well within our capabilities, and it has a lot of Craftsman-style character that will make it cozy and appealing when we’re done. It’d be a great place to live, within a few blocks of many of our friends – it’s actually just a mile further down the road we currently live on.

I’ve always been scared of the financial commitment involved in buying a house, but between the low interest rates and the depressed housing market, the monthly mortgage & tax on this place would only cost half again as much as we’re currently paying for one bedroom of a house shared with two other people. The place is big enough that we could easily continue sharing space with friends, too, making it even more affordable.

I get the impression that most people who rave about Git are really not so much talking about Git specifically as the notion of distributed version control in general. Take, for example, this very helpful cheat sheet: the features the author gets excited about are those every DVCS shares, while git itself is such a complex beast that it justifies this kind of lore-collection.

Maybe Mercurial is better. I’ve installed it on all my machines now and hope to set up a repository here soon so I can try out its workflow.

A list of publications on algorithmic botany: a long list of formulas for simulating various aspects of plant development.

Projects I am currently working on:

– Handbag for my sister Joanna
– “Walkie-textie” mesh-networked text-messaging device
– “Orb of Awesome” for Aaron B.
– Intelligent juggling ball circuit prototype
– Rhythm Robot v2 circuit board layout
– Four more bloom lights, for Eva’s flowers
– “Hammerbox” percussion synthesizer algorithm
– “Steadyrocker” MIDI clock device
– Helping Chris W. and company build blinking firefly costumes

Projects I am not working on, but wish I were working on:

– Sell the older two of my three motorcycles
– Install the new Corbin seat on my Suzuki
– Fix the grille on my car so the hood once again stays latched
– Summer jacket, in grey cotton twill
– Red shot silk dress w/gold lining
– Radian
– Tuning up the groovik’s cube dimmer code
– Fixing Adam’s light-up hoodie

The LeafLabs blog has an article on realtime audio processing with a Maple board – particularly interesting as realtime audio processing is exactly what I want to do with the Maple board I bought a few weeks ago. I haven’t had a chance yet to do more than make its LED blink, but the design of my upcoming percussion synthesizer is an ongoing mental background thread.

The Octatrack is an upcoming multichannel sampler/looper device from Elektron, makers of the Machinedrum. It’s good to see someone looking after the hole in the market left by the departure of Electrix and its marvelous Repeater, which is the cornerstone of my live-PA DJ rig.

The Dropout’s Guide to Antenna Design looks like a great reference for people like me who know almost nothing about antennas. I have been learning a lot about digital electronics over the last year or so but I am a total ignoramus when it comes to analog signal processing.

The first batch of Xbee modules I ordered had wire antennas; when Adam ordered his, he picked one with an external antenna. I think this is a better choice for long range, so I ordered a little SMA connector and am going to solder it on to my existing device.

Yep. Sure is. That is what this day is, among many other things. Carry on!

I spent a couple hours making a spreadsheet last night. This might not sound like much for someone who has been using computers since the early ’80s, but it is in fact the first spreadsheet I have ever made (unless you count all the copies of the “invoice” template I’ve used for contract billing). I wanted to figure out how much it would cost to build a rhythm robot, as a function of the size of the production run. It’s an interesting curve: there are steady price breaks at 10, 25, 50 units, then a big drop at 100 – but almost no improvement at 200. I didn’t track price breaks larger than that, because it’s difficult to imagine producing, selling, and shipping that many items without making a full-time job of it, but it might be interesting to do the math anyway just to see how the production would work out.

Next I need to estimate what the “demand curve” for this product might be: how many units could I sell at each possible price? Once I have that information, I can join the two functions and figure out whether there is any range of prices at which I could profitably sell rhythm robots.

Of course there are always more complications around the corner. I’d still need to figure out how much it would cost to advertise, how much to factor in for assembly time, and then there’s the whole terrifying nightmare of taxes and lawyers and incorporation, which might just kill the whole thing… I’m not actually sure there is a real business here, or that I really want to pursue it even if there is. Regardless, I’ve never done this kind of analysis before, and it’s an interesting learning process.

I was never particularly interested in the whole Holga camera thing, but this Holga-D digital camera project hits almost all the right design notes. It has a simple geometry, minimal interface, and generally looks like something I’d love to cart around. It’s just a concept so far, but it’s a good one; I hope they produce it.

There’s actually an old Kodak TLR in my project drawer waiting to be turned into a digital camera. The project has never ranked very high on my to-do list, but someday I want to pull out the film holder and mount a CCD in its place, with an SD card holder, a microcontroller, and a battery pack hidden somewhere in the volume. I wouldn’t bother with a viewfinder, a flash, autofocus, or any of that: the goal is to create a simple, manual camera that just happens to take digital pictures.

The MCP4725 is a cheap, simple 12-bit DAC chip. It works on a single supply, both 3.3V and 5V are fine, and has an I2C interface that runs at 100K, 400K, or 3.4M. Sounds like a pretty solid performer to me.

postscript: here’s the MCP4921, a very similar chip with a SPI interface.

It was a fun weekend, alright: Ava and I spent Saturday hiking up to Pratt Lake and back. We got started late in the day, so we didn’t hike all the way around to the far end of the lake where the trail ends, but we had a nice little picnic on a sunny rock with a great view. It was a beautiful Alpine Lakes Wilderness trail – all ferns and salal in the understory, little streams running across the trail every so often, some nice waterfalls, firm steady earth underfoot.

We were pretty tired when we got back – it’s a twelve-mile round trip – so we didn’t end up going to Dawn’s birthday picnic after all. We picked up a couple of chirashi bowls from Hana and sat on the front porch watching the cars and the sky. I lasted a little longer than Ava did, and walked a few blocks over to Gary & Jaime & Nell’s housewarming – they are neighbors now!

I felt like my set went pretty well Friday night. I had no time to prepare, so I had to just jump in and wing it, but my style is designed to incorporate a lot of improvisation so it worked out alright. I got some pretty solid grooves going, and there were some wobbly bits but only one outright trainwreck (which I could have avoided had I brought the rhythm robot – oh well).

My current sewing project is a handbag; it’s a gift for my sister Joanna, which I’d hoped to have ready for her birthday. I ended up designing a somewhat more complex object than I’d originally made time for, which is good in terms of it being a nice present, but it does mean it’s going to be a couple weeks late. I’d hoped to spend some time finishing it this past weekend but did not succeed; maybe I’ll get it done on Wednesday, which I’ve set aside for sewing this week.

Other projects under way: now that the bloom lights are finished, my focus for electronic work is the walkie-textie. Adam has bought a set of parts for a second prototype, and once we get both devices wired up we’ll do some range tests and see how practical this system can be as a wide-area mesh network. I’ve also been doing some design work on the intelligent juggling balls; I have no idea whether any of what I’m doing will end up in the final product, but I’ve never done electronics CAD before, and this is a great excuse to learn some new skills.

The Maple board I ordered arrived today. I don’t have any immediate projects for it, but I would like to expand my design comfort zone to include higher-powered microcontrollers, and the STM Cortex-M3 seems like a great place to start. I think the first thing I try with it will probably be a percussion synthesizer device, as a companion to the rhythm robot.

This very nice little graphic shows the relationship between Arduino pins and the ATMega328/ATMega168, plus a schematic for the minimum possible arduino clone.