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I basically skipped out on the Internet for most of last week. This was mainly because last year's router decided it was no longer interested in putting out a consistent enough signal for my WLAN interface to stay stapled to it long enough to do things like, oh, open a webpage. I am happy when things consistently work, I can troubleshoot them when they consistently don't work, but intermittent functionality interspersed with HA HA ONLY KIDDING makes me want to break stuff. Last year's router is now no more broken than it got to be on its own, but it has been replaced with 2007's never-used router, which was picked up at a Fry's in Vegas for something like $15, preemptively disassembled in case we needed it for a project we were working on that Defcon, and put back in its box still in pieces with a few extra bits attached. All the solder points are neatly covered in electrical tape, and it has red and black wires soldered to the pins of the 5V jack; I guess if we have a power outage we can run it off batteries. Also it works, which is always nice to discover when you put something back together. Clearwire, I take back most of the bad things I ever said about you; you are actually rather fast and reliable when used with non-gimpy hardware. Perhaps this summer we will share the internet on the beach at Oostende after all, with the help of the battery-powered router.

The router needs a name. For the last few years our naming convention has been "places that do not exist" -- thus far Arcadia and Erehwon. I am leaning toward Ruritania or possibly Latveria, though I note that Uncyclopedia's list of nonexistent places includes Belgium. The humour is hit or miss, but I cannot deny the truth of the following excerpt:
Belgium is the worst place to live during a Zombie Apocalypse due to the fact that there's more dead soldiers buried there than people.
I mean, if you're in Colma when the zombie apocalypse happens, the odds are stacked against you, but you'll be up against zombie hippies and dotcommers. I suppose our only hope will be if the zombie French and Germans hate each other more than they want to eat the brains of living Belgians.

The other cool discovery, in addition to Working!Router, was the SMT tweezers that I apparently also picked up during that Fry's expedition. These are no ordinary tweezers; they are large and sturdy with a business end that comes to needle tips, suitable for performing reconstructive surgery on fruit flies. I suppose I should really get round to converting a toaster oven into a reflow oven, since I now have most of the other tools I need to do serious tiny-circuitry work. The local hardware store even sells ferric chloride, though not in the handy solution form that Radio Shack dispenses -- no, here it comes in foul-smelling rusty orange lumps and must be weighed out by the gram. I can also obtain a wide assortment of useful acids, bases, and salts, in addition to the standard sodium hydroxide and 30% hydrochloric acid that they sell in the grocery store to clear out drains. I feel like I'm living back in Thomas Edison's day, when you could get kicked off a train for having your chemistry set accidentally set a boxcar on fire.

This weekend was also [ profile] enochsmiles' and my third wedding anniversary, which would have been great had I not woken up with some gastrointestinal weirdness that forced me to instead spend the day puking myself stupid. (If you find that resultative construction unusual, I defy you to maintain any kind of intelligence while lurching to the sink every half hour to retch bile.) We are planning to celebrate this weekend instead; it will also be my little sister [ profile] briaer's birthday, so that's two reasons to celebrate.

Finally, in the last bit of router-related news, now there are router botnets. This should surprise approximately no one -- "I bet I can put Linux on that" metamorphosed into "I bet I can drop a botnet on that" some time back, for values of "that" which can connect to the Internet -- but seriously, people, password your fucking routers already.
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Good hacking night last night. D came over so that we could hack on owen, my little NSLU2 box that's been on the shelf for, oh, a few years. After a few false starts (involving things like having to remember passwords I haven't used since 2005), we threw together a quick LAN off my laptop, got owen on that network, and successfully logged in. We then figured out that trying to configure a bridge between eth0 and ra0 was more trouble than it was worth, so no updating owen straight from the package server for now. I'll need to get the switch set up before I can actually drop owen on the main network, and I don't have the furniture for that right now, but owen clearly still works like a charm and now speaks DHCP, so overall I'll call that a win.

Our eventual goal is to set up pokylinux, as a "just to see if we can, since there's not a pokylinux build for this particular hardware yet" project, which will probably involve doing some compilation on the box itself. That's going to be slightly hilarious; I haven't done a multi-day toolchain build since, oh, 2001 or thereabouts. Good times.

Laterish today I'm going to pop round to the electronics store that also sells RC cars, planes and helicopters to see what my battery options are; I assume it's easier these days to supply 5V/500mA off something rechargeable than it was four years ago. (I need to be gainfully employed before I can actually buy one, as I expect sticker shock, but this is how budgets are made.)

I also dug up the little USB-to-Roomba-serial-interface circuit I was assembling some time back, and found the ostensibly Linux-compatible Bluetooth and 802.11g dongles that have been waiting ever so patiently. Yep, that's right -- after far too long on the shelf, the Evil Robot Vacuum Cleaner Army project is rolling once more.
maradydd: (Default)
The good thing about being an electronics nerd is that even when you're not doing too well financially, any day can still be Christmas thanks to vendor free sample programs.

Today I ordered a bunch of freebie parts for a couple of projects I'm actively working on (for varying degrees of "active" -- the 32-bit ARM Cortex uCs will probably collect a bit of dust before I bust them out), but I think next time I'm feeling really down I'll just work my way through Limor Fried's list of where to get samples and call it retail therapy.

(I am, however, tempted to try to come up with the weirdest possible combination of parts, just to give the sales reps a more interesting afternoon. "What could she possibly want with capacitive sensors and a handful of transistors rated at 1500V?" Sort of the electronics equivalent of going through the supermarket checkout with condoms, kitty litter and two gallons of Wesson cooking oil.)
maradydd: (Default)
I just heard back from the vendor I met recently who sells glove-mounted fingertip blinky lights and other neat rave toys -- the electronics in the fingertip lights are mounted on a circuit board 14mm in diameter, which just coincidentally happens to be the size I managed to get a draft of an acceleration-sensitive 4-LED board down to (when I was trying to figure out just how small I could make this circuit). w00t!

Now to figure out where I can get a few of these prototyped on the cheap, since I am pretty sure that it isn't possible to prototype a board with 8-mil traces using the iron-on method. (I would, however, be delighted to be disabused of this notion.) Any clever ideas, readers?
maradydd: (Default)
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?
maradydd: (Default)

Seven ports! I need to make a really short USB cable so that I can hook the chording glove up to it.

Four on the inside, three on the outside. USB-mini in the back, optional power supply.

The wristband is a padded velcro thingy that the company that a guy I know works for ordered by mistake. Normally, a smaller beige plastic holder for a barcode scanner velcros onto it; I took the velcro off the plastic thingy and put it on the hub.

My original plan was to get one of those four-port unpowered jobs, mount it in the original plastic housing, and also add slots for SD cards. I may still do that, since the guy has lots of these wristbands available. This approach means less work to do with a Dremel, but I like the idea of storage on the go. Perhaps one for each wrist, to support keyboard and mouse. (Hey, if I ever don't feel like chording but have the rig set up anyway, I can just plug an ordinary USB keyboard into my wrist!)

If I do make a custom wrist-mount, I might go all out and make a PCB for it using this approach.

ETA: Three hours in, I'm still wearing it comfortably, which is impressive for me, since I usually fidget like crazy with bracelets, watches and things like that. I did flip it to the inside of my wrist, because I realised that the titanium bracers that Chris++ is making for the sleeves of my leather longcoat will go on the outside of my arms, leaving no room for an outward-facing hub, but I think it will fit okay on the inside. Worst-case scenario, the velcro straps are long enough that if I have to, I can wear the hub on my bicep. Time to get one of those retractable USB-A/USB-mini-B cables, the clicky kind.

Photo meme

Jul. 9th, 2009 04:49 pm
maradydd: (Default)
Snagged from [ profile] michiexile.

1.Take a picture of yourself right now.
2.Don’t change your clothes, don’t fix your hair…just take a picture.
3.Post that picture with NO editing.
4.Post these instructions with your picture.

Me and my Arduino NG, with the accelerometer I just rigged up to it.
maradydd: (Default)
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.)

[ profile] 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.
maradydd: (Default)
Dear LJ Genie,

Here is a picture of an audio cable:

an audio cable

I know that I can go to Radio Shack and buy a screw-together or snap-together end for an audio cable, but the friend on whose behalf I am asking doesn't need an audio cable; he needs to provide more mechanical stability for a join, and layered heat-shrink tubing doesn't look nice. Is there a name for the thick plastic part of the cable that one holds onto while inserting the male end into a socket, such that I could search for it on digi-key?

ETA: It's a strain relief boot. Thanks, [ profile] grepmaster and [ profile] tikiking!
maradydd: (Default)
Oh mighty LJ Genie: what is the physically smallest one-axis accelerometer I can source? (Preferably one that also has a development version available in DIP so that I don't have to jack around with breakout boards. I am willing to hand solder up to QFP .5mm pitch.)

Also needed: tiny 8-bit microcontroller. SOaCs with integral accelerometer acceptable if they're smaller than the amount of space required for an accelerometer and micro together. AVR preferred, Freescale completely acceptable, will learn PIC if required.

ETA: yes, I will be outsourcing fabrication, but would like to prototype on larger-scale equivalents, kthx


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