Archive for November, 2007

| grep snow

Datestamp entry and obligatory ‘snow’ entry (along with half of livejournal) :-P This Tues. morning was our first unambiguous snowfall for the year.

But while I’m here: HAL’s big-screen LCDTV came in the mail today. By “came in the mail” I mean we trucked our asses through the Nostril Bridge (I guess it only looks sinister and nostril-y at night) and down to the UPS plant where we picked it up, because UPS doesn’t believe in the concept of people being at work (not home) during the daytime, but the screen is pretty damn sweet. With packaging it turned out to be the exact optimal size; the absolute largest that could conceivably fit in my car (another half inch and it wouldn’t have made it!). For other house stuff, I got around to connecting up the basement sink*, replaced the front door can-spring after last week’s strong winds decided our storm door was a pull toy, found the wobbly toilet’s bolts are plenty snug on the toilet side (meaning the loose end is what the toilet connects to, i.e. the bathroom floor, which is never good), and got an estimate from the hardwood refinishing guys who should be going to town soon. Apparently the Big Machine they use for sanding draws so much power that their common powering method is to unscrew the front panel of the breaker box, remove one or more of the large breakers and jack directly in! HAL mounted a formidable (but compact) dual-LNB “IndirecTV” dish (arr, matey) to the back porch and pointed it in the direction of the ballfield, a patch of sky where I’m told French Canadian porn Red Green lives.

Last week, dug up the sweet potatoes. I’m surprised we got so many; not just have to figure out what to do with them. Kr* passed on some recipes, but they involve baking and exotic baking ingredients, such as “flour”. :-P Incidentally, potatoes make a great tool for removing old rotted light bulbs after the glass breaks off and leaves the base in the fixture**.

* Secret to success using an army of Home Depot-grade size couplers and gender benders: plenty of thread tape and a VERY BIG WRENCH.

** provided you remembered to turn the power off first; otherwise it becomes a great way to test the tensile strength of your underpants.

Takin’ Care of Bullshit, everyday

This week was the week of dealing with billing-related BS – namely, clearing up why the city is still sending tax bills to GJM (in Texas), a discrepancy between the written and printed oil bills we got, and suspicious charges on my last mortgage statement. The first two were quickly and easily resolved. As for the last…

I rang up GMAC Mortgage this Friday, after finding they’d double triple quadruple-billed me for a Payoff Statement, a routine piece of refinancing paperwork. (A refinance is basically taking out a new loan and using it to pay off your old one, usually on finding that you can get one at a lower rate than your current one. The payoff statement tells you–or your closing guy–given a near future date, the exact amount to pay on that loan on that date to pay it off. In other words, an interest calculation that’s done by the computer at the click of a button. How mortgage companies can justify charging $20-$100 for one of these is anyone’s guess**, but that’s a whole different rant entirely.)

I’ll spare re-recounting the details, you can read all about it in my demand letter to GMAC (after repeated calling to customer service reps got me nothing but elevated blood pressure and a contact Indian accent).

If ever you’re planning to contact GMAC about an error they’ve made, do yourself a favor and don’t bother. Type out your complaint on its own sheet of paper with your full name and account number, jam it into an envelope with any evidence, and send it certified mail in accordance with RESPA Section 6 (12 U.S.C. Section 2605). (It may help to include text such as “Qualified Written Request under RESPA Section 6” at the beginning of the letter, but this isn’t necessary for your letter to be a qualified written request they are required by law to respond to.) My experience thus far is that the reps are generally pleasant and inoffensive (though maybe worthless*) until you suggest the possibility that GMAC has made a mistake; then they start stonewalling. After the first rep refused to hear it I wrote him off as the occasional bad apple (curry), but after the same from a completely different rep I pretty much have to conclude that it’s policy.

* I had to contact them once before to make sure a tax payment they were supposed to send actually got sent. They were polite and quick to verify it, although I never did receive the proof of payment they promised to fax “within 24 hours”.

** one could also wonder why I’m making a stink about a whole $60 in spurious charges when compared to the loan amount, but I’m not one for swallowing bullshit, whether it comes by the bucketload or the spoonful.

Nintendo DS Lite power (current) consumption, part 2 (and other stuff!)

This is a continuation of this post, where I hooked up an ammeter as an afterthought while changing the fuse I blew in my DSLite. I didn’t have any games with me and hadn’t fixed it up to sleep with a SuperCard, so these additional numbers are below. Check the prior post for stuff about battery life impact of different brightness levels, DS vs. GBA mode, WiFi, etc.

All the numbers below were taken with the DSLite backlight set to the lowest brightness setting.

Sleep Mode current (DS lite “on” and flipped closed)
This was measured at 1.77mA and 2.31mA, depending whether the blinking green LED is on at the moment. There is no measurable difference between when sleep is entered at the boot screen with no cartridge, or with a cartridge in the middle of a game.

SuperCard SD users will be mildly upset to know, however, that this device is drawing a constant 35mA at minimum at all times, even when the DS is in sleep. Hardware mods, or a dummy cartridge in Slot 1 (to pull the INTerrupt line low) will prevent annoying sleep/wakeup loops, but it won’t allow your system to take long naps.

Cartridge contribution:
Basically none while the cart is not actively being accessed; e.g. sitting at the boot screen, cartridge inserted / not inserted has no measurable effect (<<1mA).
Conspumption of 54.6mA at boot screen raised to average of only 60-63mA at Super Monkey Ball title screen (2 screens + sound), with very occasional highs of about 74mA during vigorous play with both screens active, 3D, sound, touching, basically everything except wifi. Touched / not touched makes no measurable difference, in case anyone is wondering. Cartridge access is certainly a lot less power-hungry than continuous Flash/SD reads.

NDS Lite with external antenna
I got a broken “parts” DSLite cheaply on eBay for any ‘dangerous’ hardware experiments / mods (I didn’t want to risk my good one again with homebrew hardware in the cartridge slot), and the replacement screen it needed. So while it was open, I figured I’d try plugging in an external antenna. This was a pretty disappointing test.

Antenna used was Unigen partnumber UGADA0B1M1050M-IN or similar (4″ swivel w/ 50mm mini-coax tail, 2.0dBi), which was a spare I scavenged from a helicopter blade testing instrument I designed a couple years ago. Certainly no monster, but I thought it would outperform or at least not suck compared to a copper pattern etched on a 50-cent circuitboard. The DS’ builtin antenna wins by a statistically significant margin. Now a pre-amped Yagi coffeecan will certainly boost your range, but then the DS isn’t exactly such a portable hackytool anymore, and you might as well lug your laptop…

DS wifi module (Mitsumi DWM-W004, DWM-W006 or equivalent) mating connector:
I found and sampled some connectors that will mate with the DS’ mainboard wifi connector and the Mitsumi module, respectively. These part numbers are Molex 53748-0308-C (Digikey p/n WM24014-ND) for the “plug” (mates w/ DS mainboard), and Molex 52991-0308-C (Digikey p/n WM24008-ND) for the “receptacle” (mates with wifi module). I’m not sure how they decide the nomenclature of which is which; both pieces look a little gender-confused if you ask me. These may not be *exact* crosses (indeed, what’s on the official Wifi module doesn’t look like a Molex part at all, while the one on the motherboard most certainly is), but they seem to mate correctly. They are not keyed to prevent backward insertion, so take care.

Order one and you can use spare DSLite wifi transceivers (if you can get them) in your own projects; order both and you can make a daughtercard shim between the DS and the module to tap off signals to a logic analyzer. It would be nice to definitively log the communications required for init, various functions, WPA configuration, etc. The DWM-W006 is (if I remember it right) the same module as in the Wii*, which does support WPA. Wii should give a little more room for a shim board too…

* actually, based on photos of the Wii’s transceiver they’re not pin-compatible and probably use different chipsets, although they have the same FCC ID. Ok, FCC, you’re on crack.

CPA / tax jockey needed

To get my small business (sole proprietorship) off the ground and…er, buzzing. Or just provide good answers to a few home-business tax questions. Anyone? …Bueller?

* * *

I spoke to a lawyer yesterday (relax, not due to an unsolicited FedEx…this time ;) about starting that shindig up using a “least-cost least-risk” approach. (I’m not a gambling man, not even with 96 silver bullets on their way to my doorstep, so I’m not incorporating and all that expensive, complex jazz.) Mostly, I was looking to find out the recommended approach to dealing with a SO/HO in regards to the Tax Man, the Zoning Board and other legal ne’er-do-wells. Unfortunately, he wasn’t really able to tell me much aside from “get thee a CPA and ask them”, so that’s the next step. On the bright side, he was able to tell me that if I’m not running a manufacturing facility or brick-and-mortar shop with foot traffic (only online sales), zoning won’t be an issue in a single family home. (Although the same could apply to an apartment/condo too, many rental agreements forbid use of the space for commercial activities.)

It sounds like the most basic approach is to start as a sole proprietorship, will not need an EIN (no employees*), and might be almost as simple as filing a Schedule C / C-EZ profit/loss form with my tax return. There is also a free (beer) version of QuickBooks suitable for microbiz accounting purposes. Catch: To sell stuff under anything other than my own legal name (without having my name legally changed to “Drmn4ea Tech.”), I’ll have to file a DBA (Doing Business As, or Business Certificate) form with the city, for which they “strongly recommend” having your approval from the Inspector of Buildings handy. (The who now?) Per the advice I received, this (zoning stuff) “shouldn’t” be an issue (although in practice, I don’t know of any municipality that can smell pie without lining up for their own cut).

* as much as any of my friends might like to be a full-time, paid part of this balanced breakfast, having employees opens a big huge can o’ tax ID, federal income withholding, health insurance and potentially even OSHA worms.

Drmn’ Vibe netdemo at Intro.Inter.Tech

First off, there is a [Big Photo Album] with pics and videos of many of the pieces. (Audio-centric ones didn’t document well since my camera seems to assume the microphone(s) are just there for the photographer to talk to it, and any sound that occurs in front of the camera is just noise.) Also, the chat log of random strangers from the demo app is posted in case anyone is interested. Not everyone bothered to change the previous user’s screen name setting before chatting in it (or changed it later), so names may not exactly map to people.

For this piece two laptops were set up on tables facing away from each other, with a USB trance vibrator attached to each. The demo application, shown in ths post, was running on each machine, one as the client and one as the server. (Wireless was non-existent on one machine and hosed on the other, so they were connected with a hub and plenty of Cat 5.) Participants were invited to chat with us or one another and drive the vibrators. The whole setup, complete with stark black and white desktop backgrounds, was meant to be cold and anonymous (although in practice, in a 1-room space the participants can see each other if they turn around).

Results: People had fun with it, and a vibrator bullet ratting around angrily on the table is a neverending source of amusement ;-), but the general consensus was that the whole setup was a little eerie, made moreso by the fact that they were on public display with people walking by (as opposed to typing dirty in private), and that the participants could still turn around and see each other. It seemed a majority would prefer complete anonymity in their play, being able to have fun with a wholly unknown user and then disappear, without learning their partner’s identity or divulging their own.

(These sentiments were echoed by some participants in Rebecca’s piece, which was set in the “virtual sex” scenario of many future movies past. The setup was a pair of cameras mounted in acrylic cubes, sitting on adjacent mats representing individual pods that could be physically in the same room or a world apart. After applying a Saran Wrap condom (remember kids, safe cybersex!) to their cube, the users would each use the cube in place of their partner, with the video feeds superimposed on a single projection screen. For example, by each making out with the cube surface the two would appear to make out with one another onscreen. Participants revealed how hesitant they felt engaging in this ‘intimate contact’ with a stranger sitting next to them, even if all they were really having contact with was a plastic cube.)

As a complete afterthought, the built-in Webcam on one of the laptops was enabled, with the video showing in a window on its own screen. It seemed to me to mesh well with the overall theme of anonymous cybersex with a partner you will most likely not meet up with again, since there one is probably in it mainly for oneself (as opposed to, say, pleasuring random strangers without reciprocation)… looking into the on-screen window to see the object of your pleasure, and finding your own face staring back at you.

A stitch in the time domain saves nine

So, there I was contemplating the easiest way to decode (as a non-keyer) the single-frequency pattern, reminiscent of Morse Code, hiding from time to time in the background noise of the Evanescence song My Immortal. (Yeah yeah, formally admitting that I listen to that stuff.) As an afterthought while thinking of the changes I’d need to make to my already-existing Matlab Fourier Slicer (R)(tm)(c) for semi-automated decoding, I Googled to see if maybe some equally obsessive sap had already done the work for me. Aww, le disappoint.

When/if the GAS tank* refills, I might apply the slicer to looking for patterns in the noise of some industrial stuff. (Although in all reality, this easily exceeds the tank’s maximum capacity.)

* the notional tank that buffers my Give-A-Shit reserve for a rainy day.

IEEE Sez: Open Source == Terrorism!

No, that’s not a typo, and not (much) of an exaggeration*. For a limited time, you can read the full article here in IEEE Spectrum of all places (IEEE is the Institute of Electrical and Electronics Engineers). But basically, it exists to draw none-too-subtle comparisons between Iraqi insurgence and the Open Source movement, drawing heavily from essays and interviews with John Robb.

“Need a missile-guidance system? Buy yourself a Sony PlayStation 2. Need more capability? Just upgrade to a PS3. Need satellite photos? Download them from Google Earth or Microsoft’s Virtual Earth. Need to know the current thinking on IED attacks? Watch the latest videos created by insurgents and posted on any one of hundreds of Web sites or log on to chat rooms where you can exchange technical details with like-minded folks.

Robb calls this new type of conflict “open-source warfare,” because the manner in which insurgent groups are organizing themselves, sharing information, and adapting their strategies bears a strong resemblance to the open-source movement in software development. Insurgent groups, like open-source software hackers, tend to form loose and nonhierarchical networks to pursue a common vision, Robb says. United by that vision, they exchange information and work collaboratively on tasks of mutual interest.


To understand open-source warfare, it’s instructive to revisit Eric S. Raymond’s 1997 manifesto, The Cathedral and the Bazaar, in which he describes how a large community of open-source software hackers created the operating system Linux. […] Mimicking open-source developers, insurgent groups “hack at the source code of warfare,” Robb says.”

Wow. This reads like an article about Youth Culture in Reader’s Digest. (In addition to parroting that familiar old “kitchen science two-part explosives” canard.)

*Necessary qualifications: 1) “IEEE” here means IEEE’s Spectrum magazine, and contributing editor Robert N. Charette. The IEEE itself has not actually released an RFC or policy statement to this effect. 2) The article initially refers to the Bad Guys as “Iraqi insurgents”, later defining them equal to terrorists and using the terms interchangeably. (I’m a little rusty on my war, but I think you lose the ability to cleanly label your opponent “terrorists” once engaged in a formally-declared war with each other, even if they fight dirtier than you.)

PQI Update

My rant on PQI has been updated; they have made good on their warranty (actually as of last month, but I hadn’t gotten around to updating it).

DorkbotBoston haunted mansion at Willoughby & Baltic

[Pictures! The world needs Pictures!]

So after some late nights hurriedly hacking some stuff together, HAL and I got our stuff together for the haunted mansion. Between work and girlfriend schedules, there wasn’t much time to really polish anything. On the short notice we did a snowy owl that wigs out (eyes fade from green to red and flash menacingly, bird screams and vibrates) if someone comes too close via light sensor, and the man-eating Oobleck blob monster shown here (albeit a less noisy version).

Other pieces there included:
Fairly convincing molded Jell-O brains, sitting on metallic plates wired to a capacitive touch sensor circuit. Every time someone scooped a spoonful (adding capacitance via their body and the metal spoon), the brains screamed! (Or bantered amusingly with the scooper)
A ghost fish that would appear out of nowhere and swim to wherever you tapped on its tank
Too many great things to list; look in the photo album!

There isn’t really much code or reusable design to come out of our projects (other than a new and finally “release-worthy” Blinkenlichten revision, which I will document soonish), just some findings.

Glowstick juice does not mix with Oobleck. It’s oily stuff and it doesn’t smell too nice. (Highlighter juice is water-soluble and does mix with Oobleck; it fluoresces nicely under blacklight.)

Critical specifications for an Oobleck monster: it sits on a flexible membrane, which displaces up and down by different amounts at different distances from the center (obviously, by a lot in the center and not at all where it’s constrained to something else at the edges). The membrane’s active pushing/pulling/flexing of the goo is critical; placing the mix directly on a speaker cone won’t do much (the speaker cone is rigid by design and will just hop the mixture up and down, not flex it). A piece of garbage bag or plastic grocery bag pulled taut over the speaker (creating an sealed-ish air cavity) works well. The membrane should be covered with the minimum amount of Oobleck necessary to create the effect (and/or hide the membrane, if that’s important); it doesn’t take much to completely dampen the membrane’s vibration enough to ruin the effect.

Putting a big angry vibrator bullet in a plush toy does not make the plush toy vibrate around angrily. (If someone reached out and touched it, they could kinda tell that it was vibrating.)

We used the voicebox of the plush snowy owl, which was recorded from an actual snowy owl. It was far more disturbing and eerie than most Halloween toys that make scary noises.

Off-the-shelf toys from Target (we scavenged sensors, and ultimately the whole sensor/amplifier board assembly from one, since it was faster and cheaper than overnighting similar sensors from Digikey et al) are fast and cheap, but the guts are not Designed For Manufacture. (DFM is one of those big buzzwords floating around engineering circles these days, learn it. The idea of making something repeatably manufacturable as opposed to a one-off basement hack repeated millions of times has been around since the Model T and before, but buzzwords make you appear smart.) The circuitboard alone consisted of a custom epxoy-blobbed ASIC mounted on a small daughterboard that soldered at 90 degrees into a 2nd board consisting of all through-hole parts packed very tightly together, possibly hand-stuffed, with dabs of hot glue everywhere holding components in place and taming the sprawling mess of wires leading directly off various points of the board to motors, limit switches, sensors, etc., all of which where glued into place in some complex fashion. The circuit was crammed onto the (single-sided!) board as tightly as possible, despite the tons of empty space inside the toy.


After posting the previous post and image, with link to where the show in which the project depicted in the image is being shown is being promoted*, server logs indicate the image was picked up from LJ and used by the automated script of another art project that same day. Coincidental and eerie.

* particularly nastily nested expression; should have parentheses.


Quick ‘n dirty, but my demo for the show is almost finished. Powered by maraschino cherries and vodka ;-)

The show will be this weekend, Sat. 11/03/2007, 2-7pm.

ULA Cafe / The Brewery Complex
284 Amory St.
Jamaica Plain, MA

It’s aaaart! Bring your friends!

Figure 1: "oh, beep me again!"