A Detour

I figured it would come to this. Minor setback -- the Zaurus's serial connector doesn't provide power (more specifically, it doesn't provide enough power), which makes the accelerometer useless out-of-the-box. It works fine and dandy on my PC, but the Zaurus can't drive it just yet.

There are two options:

• create my own serial cable, splicing the power wires to run to a separate power sourcepower
• power the accelerometer directly

Either way I'm in the land of soldering. Now, I've constructed some pretty basic circuits in the past, and done a good deal of cable splicing for theatre stuff, but I don't feel comfortable doing work that's potentially dangerous (at least, dangerous for the equipment) without some training. Or at least some practice.

Since I don't have the time/energy/money to actually take a class, I'm thinking of giving Electronic Circuits for the Evil Genius a try. It seems like a fairly thorough introduction, but doesn't assume you need to be told what electricity is. I took AP Physics -- I know what a resistor and capacitor are, and once upon a time could decipher a circuit diagram. I see this as a combination refresher course / hands-on training opportunity. I'm all about the hands-on. (If anyone knows a better resource, please feel free to interject. That book is recommended by MIT OpenCourseWare, so I'll take that as a fairly respectable endorsement.)

So that will probably take a little while before I'm comfortable enough to actually tackle this part of the project head-on. That's ok. It's not like I'm working towards a deadline or anything. Hobbies rock.

It seems that someone (Matt? The same Matt I know?) from the Center for Applied Biomechanics (where I worked during the summer of 2004, programming databases) found this blog recently. How he found it, I don't know, but he provided some useful feedback on the data analysis and capture. Pretty neat! Maybe some more useful people will drop by and give me hints.

Adventures with the Zaurus

Fourth of July weekend, and I'm spending some time getting used to the Zaurus, so it can be more amenable to my means when I later use it as the brains of my little operation.

First a picture:

You can see here the Death Star orbiting the forest Moon of Endor. Er. I mean.

You see the Zaurus, sitting on the ironing board that also serves as my workbench. To the left, out of frame, is a Leatherman and a rotary tool currently being put to work on a wayward Furby. It asked too many questions.

I've been fairly impressed with the Zaurus (henceforth, "Z") from a hardware perspective. It's a nice little machine, fairly zippy, and looks like it could be a pretty decent PDA if I went in for that sort of thing.

The Z's interface

It even has a tiny keyboard!

I had been told that the Z ran Linux, but was initially a little confused by what that meant. I had read about OpenZaurus, and figured that replacing the stock operating system from Sharp would give me features above and beyond my wildest dreams. I played around with it for a bit. While it certainly offered more flexibility, its configuration proved to be a bit esoteric. No stranger to Linux, I could have muscled through this, but when I found out that the easiest way to get Python running on the Z wouldn't work with OpenZaurus, that kind of sealed the deal, and I'm currently running a stock Sharp operating system again.

The biggest feature I would have wanted from OpenZaurus would have been USB networking, so I could access the internet from the Z, but it proved very tricky to get working with my Ubuntu install, and I've given up for the moment.

The next step is seeing how well the accelerometer works with the Z. It looks like there's some hooey involved in getting the serial port to act like a proper serial port, but any research into it is purely academic until I actually have the accelerometer on hand and can test it out.

The Z that I bought actually came with the Sharp serial cable, a rarity, apparently. It's even been modified to allow the keyboard to open while it's attached, which the stock serial cables don't do. But it still blocks the power port when it's plugged in, which may be something I can't live with -- it's hard to say how long this thing will have to operate in the field, but I was planning on having a battery wired to it just in case. If the power is blocked, that's no good. I might end up having to fashion my own serial cable... which means soldering. Yay.

Now let's just hope I don't brick the thing.

Additional notes on constraints

1. I love learning new technologies, especially in the context of a personal project, because under no other circumstance does a technology present itself so openly. At least, that's been my experience. For instance, I'm going to try and do a lot of the coding here in Python because:
   1. NodeBox, which I already mentioned
   2. I've been wanting an excuse to learn it
   3. this project feels like the right mix of light coding and quick development that I've heard lends itself to Python. It's also not doing anything super-fancy from a software perspective, so I won't be hitting my head on the language quirks right away.


2. I like to use open source software whenever I can. In addition to the financial benefits (yay free stuff), I like the philosophy of community driven software, especially for oddball projects like this one. :-)