Came home to this:

Got notice in the mail today that I would be contacted soon to set up an appointment to take a polygraph which is designed to convince the DOE, and I'm not making this up, that I'm not a terrorist.

So... are you a terrorist?

OK, you got me; I admit it.

The notice came with a 18-page 3-column fine print description of the DOE's polygraph policy. Presumably, it is designed to lull the reader into a lobotomy-like state which makes them more likely to succum to intimidation (e.g. the polygraph examination).

Everyone at work makes fun of the polygraph policy, it's practicioners, and generally finds the whole process insulting. Still, everyone basically lives in fear of polygraph. The reason being that the results are not scientific or reproducible and yet can have a tangible outcome on... your employment. And that is kinda creepy.

So let's hope I can keep my sarcastic mouth shut and the plotter wiggles in my favor. Ugh.

Drilled some holes in the body of my truck today. Nothing too fancy; wanted to start off my vehicle modifications with something modest. So here is a writeup on the installation of Maglite deck clips. Enjoy.

Ladies and gentlemen, my 2006 Toyota Tacoma V6 4WD Access Cab pickup truck:

Bought it this morning; got an excellent deal on it, and was not hassled at all by the dealer. As I did my inspection of the vehicle, looking for damage, making sure the requested options were installed, etc., I plugged my laptop into the engine computer via the OBD-II port and checked for any DTCs. The sales guy was fascinated. Afterwards, as he walked me around to all the various people I had to talk to during the sales process, he told every one of them about it.

After failing to sell me an extended warranty and having me sign the buyer's agreement, the financing lady actually forgot to ask me for the down payment, and handed me back to the sales guy. I was ushered out to where my new truck was waiting and told to have a nice day. I assumed that, had I just driven away, they would have figured it out... so I decided that the amusement value of watching them all backpedal was worth telling them about their mistake.

"So do you want some... you know... money for this?"

Anyway, expect gratuitous detail in the photo gallery of various truck features and probably some endless droll banter here about my experiences getting used to the idiosyncracies of a new vehicle. In the meantime, tomorrow I go to the bank and sign the loan paperwork, then move everything out of the Ranger and prep it for sale on the Lot de Lemon. Adieu, DeadGuyTruck™.

Well my strategy for gathering internet quotes and playing them against one another has paid off. I collected quotes for very similiarly-equipped Tacomas from no less than eight dealerships, some as far away as Gallup, Roswell, and Durango. The nearest dealership to my home, Beaver Toyota, gave me the second-worst quote of the bunch. But when I showed them the best quote I had so far, they beat it by over $200 and said there would be no attempts to tack on fees or anything when I come down there.

Of course I asked them to put the final price to drive it away in writing and I won't go down there until I get it, but assuming their email this evening wasn't just lip service, I'll probably go with the deal. Their price (before taxes) is fully $3500 less than the worst quote I received.

So. Assuming there's no funny business, I'll probably be buying the car later this week or weekend.

[I realize that this isn't really the endgame as I haven't yet crossed the threshold into the dealership... but hopefully the precautions I've taken will keep my visit to the dealership down to half an hour or less. Maybe I'm dreaming.]

I went to the bank and got pre-authorized for a nice-sized car loan. It was surprisingly painless. My loan officer recently bought exactly the same truck I'm after (a Tacoma) and took the time to discuss all the various options with me, what was worth it, what wasn't, etc. She also pointed me to carbuyingtips.com, which was very educational. Now I feel like I won't get as screwed when I talk to dealers.

She surprised me when she listed the options she got on her new Tacoma, and the price she payed—it was comparable to the prices I was seeing on CarMax for cars that were a few years old and had ~30k miles on them. She recommended I at least try negotiating for new trucks with the "local" Toyota dealerships and see how the numbers compare to the various used offerings.

Step one was to go to Toyota's website and pick out what the ideal Tacoma for me would be. This basically comes down to a 2006 Tacoma 4x4 Access Cab with 6-speed manual transmission, the TRD off-road options package, and the towing package.

Step two was to go to a wide variety of online car dealerships and get quotes. I also had the online places put in quote requests to all of the Toyota dealerships near me. Now I wait for the quotes to come in, and I start running the numbers to figure out A) what is their actual profit and B) on which line items is the profit being charged to me?

First to respond was a Toyota dealer in Roswell who gave me quotes on two Tacomas. One of them didn't have the off-road options which I want, and was basically irrelevant. The other one had exactly what I wanted, but also included a 6-disc CD changer, a spare tire lock, and tinted windows. The numbers indicated that he was either charging me $900 for tinted windows, or had an inflated sense of fair profit. I asked for a new quote with itemized fees and option charges.

Next response was from Karl Malone Toyota in Albuquerque (Do I get to meet Karl Malone if I buy from them? I think I should get to. Way more interesting than the set of $170 floor mats they tried to hawk me...). Malone did a nice job of itemizing their costs. However, this exposed the fact that they were charging me MSRP for all of the options. They also didn't include the off-road package that I require, so the car they quoted me is basically not suitable. They also included several options packages that I didn't ask for, but used the manufacturers codes to describe them so I don't know what they are (LF and CF). There are line items for "Dealer Holdback" and "Wholesale Financial Reserve," which are classic dealer scam fees, but they didn't have a value next to them. Perhaps this was an indication that they wouldn't charge me for them—but then why not put $0.00? I asked for clarification and a quote on a car that includes all of the options I asked for.

Once I amass a few quotes from local dealers on the truck I want, where they aren't trying to rip me off with 9% dealer profit margins and MSRP option pricing, I'll take my show on the road and bring these estimates down to the three dealerships within reasonable driving distance of my house. I'll keep you posted.

UPDATE:
Karl Malone writes back (I like to think that I'm actually corresponding with Karl himself, and he's just using the pseudonym "Ian.") with two more car quotes. The first one also does not include the off-road package I specifically mentioned being a requirement in my last email. The second one lumps on about $1000 worth of extra options I don't want. And now, there are numbers on the scam fee line items totalling nearly $700! I gave him a piece of my mind on the fees and told him to try again.

UPDATE 2:
After complaining to Karl about the glut of unwanted options in his quotes, he wrote back to tell me that these were the only two choices Toyota offered. Furthermore, he ignored my comments about the fees. I made one final ultimatum low-ball offer and am now of the opinion that this guy is not interested in selling cars to non-suckers.

After much waffling on the matter, I have been convinced to attend the Explorers Club annual banquet in Manhattan. I will be arriving in NYC on Friday, March 17th and leaving that Sunday.

I have the distinct impression that people I know live in this enormous city, but I'm having a hard time remembering who. If you live there, want to say hello, and didn't just receive an email from me on the subject, then I suck for not remembering that you live there and you should write me an email reminding me of this fact.

Cari brought home a copy of the Kitty Goes Hunting DVD. It's just a bunch of closeup animal shots... fish, bugs, mice, birds, etc.

Groganov just parked his ass about 6" from the TV and has been sitting there all evening. The DVD has a "continuous play" option. It is very cute.

And in other kitty news, The G-Man is now much bigger:

I'm currently reading e: The Story of a Number, which it turns out is fascinating. Being a bit of a geek, I've amassed a respectable collection of books about numbers.

It all started with A History of Pi, which was great reading (with the exception of when the author goes off on tangents about the horrors of the Soviet Union (??). If you're nerdy, then you're aware of the usefulness and omnipresence of this number. If you've never really had much use for math, then it may surprise you that this number was once banned by the church and people have killed each other over it. It has quite a history, going back thousands of years, and the book is entertaining even for non-geeks. There's at least one other book solely about the number pi, though I haven't read it.

The next book I read whose subject was a single number was The Nothing that Is: A Natural History of Zero. Here is another number that has quite a long history. Perhaps surprisingly, it has a shorter history than pi despite being a number that is much more clearly understood by today's modern non-mathematician. Another good book, and no ranting about Soviets this time. And as before, there is another book on the subject which I haven't read.

For my birthday this year, I received two additional books about numbers. The first was The Golden Ratio: The Story of PHI, the World's Most Astonishing Number. This is a number about as old as pi, and at least as ubiquitous (and was also, at one time, banned by the church). I haven't read this book yet but it is near the top of my list. And, of course, there is a companion book which I haven't read.

And this brings me back to the book I'm reading now, all about e. This number stands out from the rest because it is relatively new, having been "invented" around the turn of the 18th century. e comes about naturally (sorry) from the development of logarithms, limits, and exponents—all of which were being formalized during the late 1600's. It is a number with astonishing properties, and for being as obscure as it is to people outside of science and finance, it is just bizzarely relevant. e also stands out as being a number with only a single book written about it. Most numbers have zero books, several bigshot numbers have two; e is one of the chosen few with but a single book.

Some other numbers with their own books: i, Γ, and ∞ [ok ok, not really a number... but equal to the sum of all numbers... so why not.]

And an honorable mention, which is actually not about a number at all but is math-related, makes a perfect number joke, and is probably among my top three favorite books of all time: The Dot and the Line: A Romance in Lower Mathematics.

I want to write a book about a number! But it seems that all of the really interesting ones are already spoken for. I once had a book called "The Encyclopedia of Wild and Fascinating Numbers" or some crap like that, and it tried to point out interesting triva about lots and lots of different numbers. Numbers like pi and e had pages and pages about them. Then there were the somewhat more obscure entries like:

9^9^9: The largest number that can be expressed with only three digits.

fascinating.

Still lots to work on, but basic POV functionality is working. Haven't figured out good timings that make it easy to see without swinging the circuit board around yet. Here is a shot I took by panning the camera across my lab:

Anyway, I got all three PWM drivers and all 10 RGB LEDs populated now. The circuit is fully operational except for the RS-232 level shifter which I haven't populated yet. I gotta get on that, because this re-flashing the processor every time I want to change some little thing is really irritating.

...and now that I look at it, my decision to not bother with the second T in "TEST" was a mistake. I have clearly POV'd "TESTES." Great.

The RGB POV Prototype 1.0 boards showed up yesterday along with my Digikey order of sundry parts. Today was my friday off, but I spent most of it at work anyway because the rework station here blows any electronics fabrication facilities I might have at home (say, for instance... in the bathroom) out of the water.

I got the regulators populated and checked that they were working. Then I added the CPU and got it talking (this took about an hour longer than it should have, thanks to Keil's IDE having the wrong COM port assigned for the JTAG interface and burying the setting dialog somewhere unintuitive).

Next I wrote a skeleton firmware for it with a basic SPI API. Once I was convinced that I had control over the processor, I put a PWM driver and a single RGB LED on the board and voila!

Das Blinkenlight!

The nappy pair of jumper wires and trace cut in the middle there are courtesy of Silicon Laboratories having bizzarely different SPI specs on their various microcontrollers. On the C8051F120, which I'm used to using, if you aren't in multi-master mode you can use the NSS line as a chip select. And that's how I designed this layout. But unfortunately, on the C80510F007 seen here, the chip is always in multi-master mode and the NSS line is a useless input. Dorks...

Anyway, the PWM driver worked without a hitch and I have full control over the light output in both intensity and color. Next is to add the other two drivers and the other 9 LEDs and see if the daisy chaining works. Then, it's on to Persistence of Vision. Wh000t!

Jason brought an interesting physics thought experiment to my attention on his weblog. And of course I can't turn away from something like this...

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction). Can the plane take off?

Some of the comments people have left in Jason's journal have compelled me to provide a slightly more thorough physical examination of the problem. This is a pure mechanics problem, and we must examine it in terms of forces applied on the plane.

While still on the conveyor/runway, the plane is subjected to the following forces:

• Gravity, oriented downwards, constant.
  
• Lift, oriented upwards, function of airspeed.
  
• Thrust, oriented forwards, assumed constant.
  
• Drag, oriented backwards, superposition of air resistance and friction in the wheels.
  

Obviously the plane will not take off until the force due to lift overcomes the force due to gravity. For this to happen, the plane must achieve some minimum forward velocity relative to the air. Forward acceleration will only occur as long as the force of thrust overcomes the drag force.

Because the conveyor belt speed is the inverse of the plane's airspeed, we can say that the conveyor belt does not move until the plane begins to accelerate forward. Thus, rolling resistance has already been overcome by thrust when this problem really begins.

Initially, the engine thrust is considerably higher than the drag—this is what allows aircraft to take off on regular runways. So the question is, once we start moving and the conveyor belt starts up, does it impose some force on the aircraft that can overcome the force of thrust?

Certainly not initially. Consider the case where the aircraft has just begun to move through the air at, say, 1 m/s. The conveyor belt is then moving backwards at 1 m/s and therefore the speed of the aircraft relative to the conveyor is 2 m/s. If a 2 m/s rolling speed created enough friction to overcome the engines, then no aircraft could ever accelerate beyond this speed on a regular runway.

In fact, we know that at the moment of takeoff the wheels are still on the ground and rolling and the aircraft is still accelerating. So up to that rolling speed at least, the engines still win the thrust vs. friction competition. Would rolling at twice that speed cause sufficient friction?

Consider the thrust of an aircraft engine. I won't give you figures here because it depends widely on the type of engine. But... it's a lot of force. Now contrast this with rolling friction. I'm guessing here, but I think that before a wheel could provide enough friction (without using the brakes) to completely counteract an aircraft engine at full throttle, the wheel would be spinning so fast that it would come apart. At any rate, it certainly would not reach this tremendous amount of friction at a rolling rate twice that of a standard takeoff speed.

The airplane would take off normally, with the wheels spinning twice as fast as normal and a *slight* reduction in acceleration due to added friction.

I think where people get thrown off is the idea that if the conveyor is moving backwards and the plane is on the conveyor, then this must translate to some backwards momentum that has to be overcome by the thrust. But of course the conveyor doesn't start up until the plane is already moving forward. It is the conveyor that must overcome the forward momentum imparted by the engines—and the forces just aren't comparable.

It looks like I'll be heading back to southern New Mexico in May for another NMMC trip. They got permission to climb another peak inside of White Sands Missile Range and I had a lot of fun there last year.

Not in Florida.

On the way (sort of), I'm going to meet up with fellow highpointer Ken Jones and we're going to ascend Florida Peak, the highpoint of the Florida mountains (a bizzare oxymoron, I know) near Deming, NM. It is a very prominent desert peak with a great semi-technical summit push. It also has a second summit about a quarter mile off which is only about a foot shorter and offers the fantastic photo opportunity seen above.

POV toys seem to be becoming very common as of late. Some designs I like a lot, like Ada's (and her more elaborate version for use on bike wheels). Others are more clunky. But almost universally, the available POV designs are monochrome. For the most part there isn't any brightness control either. The notable exception to this was Frostbyte's Obelisk project. Unfortunately, the Obelisk wasn't open source, wasn't for sale, and Frostbyte is no longer with us. So I decided to see what was involved with making a full-color POV toy with brightness control on each color element.

Tonight I finished up the layout for an initial prototype and sent it off to ExpressPCB to have it fabbed. The design includes 10 surface-mount RGB LEDs (each 5mm x 5mm) and has 9-bit brightness control for each element of each LED. The processor is a Silicon Labs C8051F007. The board is 3.8" x 2.5" (and aside from the LEDs and drivers, I didn't put any work into maximizing the board density).

That's the LEDs and drivers in the upper-left, JTAG and RS232 connectors along the right edge, power supplies in the lower-left, microcontroller in the center and the RS232 level shifter just below that. For more techno-babble about the design, see my wiki page.

Assuming I can get reasonable results with this 10-pixel prototype, I'm going to move on to a scalable modular design with 14" long segments each with 60 LEDs and 18 drivers on them. They won't be cheap, but they should look great. :)