Radio Free Meredith

Chording glove pattern prototype, version 1, three fingers and a thumb left to knit:



I am making this up as I go along, thus there are a few irregularities that I will correct in the next version when I take my notes and turn them into a proper pattern. I realized halfway up the index finger that I'd failed to knit a solid line up the thumb side (for mounting the thumb switches) like I'd planned to, and that ugly-looking line right across the palm was an experiment that didn't quite work out and that I couldn't be arsed to go back and fix. (The fishnet pattern is made by knitting two stitches together, then making a hole by bringing the yarn to the front, over and over again. The cool spirally pattern comes from having each row of holes offset from the next by one stitch, which was obligatory when I was making increases for the thumb; I forgot to alternate when I started going up for the thumb side of the palm.)

All in all, though, I'm quite happy with how it's turning out, especially since a couple of experiments succeeded -- you can rib lace after all! -- and some things that I was worried would look stupid, like the solid fingertips (for stability, and to have a place to anchor the switches), look okay after all. Since this is an attempt to figure out a pattern, I'm making this out of plain cotton, and will wire it up by sewing 30ga wire through the knit stitches (the thicker "lines" that you see on the glove), but I still want to figure out a way to work the wiring into the pattern itself, because it will look cooler and I am stubborn like that.

Barring anything weird happening, I should have the complete standalone USB keyboard glove working sometime this week. I have my wire-wrap sockets now, and have soldered in half of the discrete components (the ones I had spares of, by way of a test run); I'm going to hold off moving the rest of the circuit from the breadboard until I have the glove finished and the switches mounted and wired, but the actual wiring-up shouldn't take more than an hour or two.

I'm kind of tempted to set up an Etsy shop and sell these, though I'm not sure how much would be a fair price. The actual knitting probably takes about ten hours (spread out over a few days, since my hands get sore quickly), and the soldering goes fast; the parts are less than $20 total. Any thoughts? Would you buy one?

First off, my apologies for the lousy picture quality. We have a really good camera, thanks to foxgrrl, but I am a terrible photographer who cannot hold a camera steady one-handed to save her life. Also, unfortunately there are no macro shots, because either we don't have a suitable lens for it or I don't know how to use our existing lenses properly (the latter is far more likely). But these should get the picture (har!) across.

So, how does this thing work?

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This post brought to you by free software. No, really. Image editing was done on my EeePC running Ubuntu Netbook Remix, using F-Spot and UFRaw for importing and colour correction, and The Gimp for annotation and resizing. And, of course, the SpiffChorder design is itself free-as-in-speech and free-as-in-beer.

Since my last update, I've picked up the necessary hardware to build a SpiffChorder, Mikkel Holm Olsen's homebrew AVR-based chording keyboard. The circuit is now mostly breadboarded, and one of my winter gloves has been converted into a prototype that looks scarily like something out of Serial Experiments Lain. ph34r my wire tentacles!

I have also fallen madly in love with the art of wire-wrapping. It's not a technique people use very often anymore, since soldering is so convenient and cheap, and almost nobody prototypes CPUs with discrete components these days -- we have FPGAs for that. However, it's a great way to hook up components that need a flexible connexion, such as glove-mounted switches that need to tie in to a breadboard. Wrap a lead, then wrap a single header pin, and voila -- breadboardable glove-mounted switch. (Also handy for connecting panel-mount components to a breadboard, using the same header trick. This worked great for the USB-B jack.)

joel tells me that I'm not the only one doing my part to keep wire-wrapping alive -- Steve Chamberlin did prototype his own CPU with discrete components, showed it off at Maker Faire, and taught Joel (and presumably many more people) how to wire-wrap. Keep the dream alive, Steve!

Now to figure out what I did with those 82-ohm resistors, finish that breadboarding job, and try loading Mikkel's hex image onto my ATMega8. Cross your fingers for me -- I want to take this to the hackerspace meeting tonight.

ETA: hm, that's strange, the ISP pins are definitely lined up correctly (my multimeter tells me so!), there's a 2.2k pullup on the RESET line, but I still get the blinky red LED of no love from the AVR-ISPmkII. Actually, first it's the solid red LED of no love which isn't mentioned in the manual, then when I try to load up the image via avrdude it's the blinky red LED of no love. Downloading AVR Studio now, we'll see if the official tools give a more useful error.

I just bought two rolls of sportweight cotton in what can only be described as "printed circuit board green".

It cost me less than 5EUR, so I'm not that bad. But I'm still giggling.

Switch placement worked well (and comfortably!) on the test glove, a winter glove that I'm not using right now. Next step is to get some junk wire and lay out the traces, as it were.