Red Echo

September 29, 2010

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

September 27, 2010

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.

September 21, 2010

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.

September 17, 2010

Rhythm Robot rev 1 prototype



I’ve just finished assembling the first revision-1 Rhythm Robot board. Where the previous prototype was a carefully hand-wired assembly of four perfboards, this is a single machine-printed circuit board. I’ve also eliminated a couple dozen passive components. Assembly to this point took an hour and a half.

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!

September 13, 2010

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.

September 11, 2010

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…

September 9, 2010

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.

September 2, 2010

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.

September 1, 2010



I picked up this pair of “Kik Girl” raver pants at Value Village for ten bucks. They were a little too small for me (women’s size 11) but I bought them anyway. Then I went over to Stitches and picked up three yards of some sturdy red grosgrain ribbon with a retroreflective stripe down the center. I slit the side of each pantleg, sewed in the ribbon, et voila! – even shinier raver pants that fit me perfectly and go well with my general design aesthetic.