Notebook list

[link] 2009-07-04T03:06:10 MegaBrite installation:

I replaced the LED nightlight in our bathroom with a MegaBrite.

I got some plastic domes on eBay. Do you want one? I have several extras.

I attached the dome to the ceiling by tying some bicycle tire around pushpins that press out against the inside of the dome. Here are a few other uses for old bike tubes.

Here are some unretouched photos of the MB with its dome lighting up the bathroom. Shutter times are 1/2 and 1 sec.

When I was testing the MegaBrite, it was hanging down from the ceiling and I happened to have a glass of water nearby:

The first two pictures are from different positions of the MB in the glass; in the third one I am sloshing around the water:

I'm controlling the MegaBrite with a parallel port, which is very simple to do. I'm getting LED power from the 5V rail of an old computer power supply. The power is going over perhaps 50 feet of cat5 which probably adds a lot of resistance. I measure 4.7V at the MB end (with the MB turned on). The parport control code is here. It has no attempt at optimization yet, and I think it takes just under 1ms to do a single update. If I add more MBs to this chain I may need to fix the inner loop in that code.

[link] 2009-06-25T19:26:28 2009 light9 theater lighting software report:

David and I brought light9 back to life again a few weeks ago to run lights and sound for an annual dance show.

Each year we put a little bit of time into the code and then design and run a show over a weekend. Then we don't think about the code for hundreds of days, which leads to time-capsule notes to ourselves for the next year. It's a little disturbing to think about the future of a code project when it has the property that each chunk of development takes 1% of your life to complete.

This year, the notes have a bunch of small technical fixes, but I wish we could make some big changes that really improve our productivity. The bottleneck occurs when the dancers are rehearsing a song and we're trying to design and test lighting effects at the same time. We only see each song a few times, so even half a second lost to 'using the software' is a concern. There need to be actions like "that looks cool, remember it", "that was right, but a bit too late-- put it on a list of things to review with music later", "make the light animation 10% busier", "give me a random, contrasting look right this instant so I can fade to it (and I'll fix up the exact look later)". These actions need to be run from either of our computers.

There are other actions that would be helpful to run remotely. Sometimes I'm up on a ladder and I need light b35 turned on and then the other two blue lights faded up and down so I can see how b35 fits in with them. Dave can do this pretty easily from the booth, but it would be a better use of his time if he was in the audience planning out the looks we're trying to acheve. Maybe I can manage to press buttons on my cell phone, or maybe we can get some voicerec working.

Like many other data-editing tools, the light9 software uses names for various entities. I don't mind typing the names for songs, for example, but it's pretty poor that I have to name the things that I want to fade up and down during a song. We end up with names like "slcross", "green", "cs1", "edge", "bpurpleall", "centercircle", etc. I'm typing those (and reading/decoding them) while a song is being rehearsed, which is the most sensitive time of all! I want to move toward images, either captured at the moment we make the look, or synthesized from photos of each individual theater light (which is easier than it sounds [my project] [Ian's project]).

I also have most of the data in RDF, which should open us up to better sharing and syncing between apps. Right now I still read .n3 files from the filesystem, so there's no improvement in functionality. I like Sesame, so I thought I'd put my data in there and use some messaging service to send pings between the apps when things change. But the Open Anzo RDF store may have figured out that notification stuff already, so I'm eager to look into it some more.

Photos of our setup in the theater lighting booth

Code repository and commit log

[link] 2009-05-19T01:42:44 Twitter follower stats:

I measured something on twitter. I have 67 followers. If you tagged a random 20% of them, how many could now look at their follower list and see a tagged user? The answer is about 20-50% of them, depending on which of my followers you tag.

The chart shows various runs of this process where the tag fraction varies from 10% to 100%. In each column, the lower + are cases where we happened to tag "unconnected" people. The upper + are cases where we tagged "connected" people, i.e. they led to a higher percent of followers seeing tagged people themselves.

There's only one way to tag 100% of my followers (hence the single + on the right), but even then, only 80.6% of them will see tagged users in their follower lists. In other words, about 20% of my followers are not followed by another one of my followers.

[link] 2009-04-07T23:46:42 US goverment secret information protocol:

So I was flipping through this official PDF announcement, more clearly summarized in this article, and I noticed a part about how "proposals submitted ... will be classified at the SECRET level". Then there's what looks like some standard language about how to handle secret data:

Classified information at the Confidential and Secret level may be mailed via appropriate U.S. Postal Service methods (e.g., (USPS) Registered Mail or USPS Express Mail). All classified information will be enclosed in opaque inner and outer covers and double wrapped. The inner envelope shall be sealed and plainly marked with the assigned classification and addresses of both sender and addressee. ...

Remember, these proposals are about technologies for scanning entire buildings through their walls, but just double-wrap your goverment secrets in opaque covers and we're cool.

[link] 2009-03-15T03:21:31 SHDH 31:

I made it briefly to SHDH 31. There wasn't much seating, so I sat partway under the piano. My dog also likes to hang out under pianos.

I met Andrew, who works on Haiku, which is a new OSS version of BeOS. We talked about email and IM data mining. I started to work on packaging my openid login system for nevow.

Here is a picture of my shoes.