Dorkbot Austin!

Natalie and I went out dorking tonight 🙂 The dorkbot made it’s second appearance in Austin tonight at Cafe Mundi. There was some great geeking going on .. I think we missed the first presentation though (got there around 8:30).

First one we saw was Joel Greenberg showing off his nifty homemade mic zeppelin. According to my links, I read about this back in April, but didn’t realize he was from Austin. (Note to self: checkout his podcast )

Next up was Rich LeGrand and his Lego-bot with a Gameboy brain. Basically, he put an FPGA and some flash memory on a card that fits in the Gameboy Advance cartridge slot, which lets the GBA brain talk to sensors and motor controllers and cameras and all kinds of roboty goodness. For a demo, the bot spotted a loose lego piece, wheeled itself over, grabbed the piece, and moved it to the other side of the table. It was also able to learn and repeat and little dance — you push the thing around the table, and it senses the movement through the motors, records it, and plays it back. ( video! )

The Austin Robot Group had the last two presentations: Eric Lundquist explained the Babbling Head and had it sing a few songs, and Vern Graner demoed the controller board/prototype of a funky spin-art game-type-thing they’re making for the next First Night Austin.

All kinds of Neat Stuff[tm] .. we’ll have to go back next month. (I heard they had a homemade Tesla coil last month!) I managed to catch part of the evening with the voice recorder on my iAudio. I’ll try to clean it up and stick it online sometime in the next few days.

[tags] austin, austintx, geek, dorkbot, dorkbotaustin, nerd, robots, robotics[/tags]

Network-enabled Garage Door

This has been in my “to-blog-about” queue for a while, and seeing this post on the Make blog tipped it into the “must-blog-now” category. Summary: combine a wifi adapter, some sensors, and some electronics and you can monitor your garage online.

A few months ago, I had a similar idea but took a different approach. I was a bit more speed-oriented (some might say lazy) and decided to use the X10 system I already have going in the house. Maybe not as elegant or robust as making a circuit from scratch and hooking it directly into the ethernet, but


I used an X10 Powerflash module connected to a reed switch mounted on the overhead door. When the door changes state, it sends an X10 code of on or off, telling if the door was just opened or closed. The signal is received by an X10 CM11A attached to the house server, which triggers a short script that logs the time and status in a text file (again, “speed-oriented” .. as in speed of completion). Another script generates a (SSL and password protected) web page displaying the current state of the overhead door and time of last change: “Garage was opened at 8:00 am”.


Now I have webpage that tells me I left the garage door wide open when I took off for work … if only I could close it remotely! Once more, with ease-of-installation in mind, I grabbed another X10 product from Fry’s, the Universal module and wired it to the same contacts that connect to the wall-mounted door-opener button. A small addition to that web script, and a click will use the heyu program to generate the proper X10 signal, causing the relay to fire and close the door.

Side note:

Our garage door has an “electric eye” to detect an object (or person) in the path of the closing door, and will reverse and refuse to close if something’s in the way. (I believe this is required by state law.) It’s still possible to close the door on your car if the bumper and the beam are at different levels, but at least it makes it harder 😉 There’s an LED on the sensor itself, but it’s hard to see from inside the car without adjusting the side-mirror to an odd angle. So there’s a possible enhancement to my version of the garage monitor: use the signal from the original obstruction sensor to drive a second better placed LED.

[tags] house,homeautomation,x10,nerd,geek,make,diy,garage,sensors,control,remotecontrol[/tags]

Nerd Hotrod

Since I got my new car in October, I’ve been planning and scheming and pondering how I would put a computer in it. Actually, a mobile car-mounted computer has been on my mental (Want)ToDo list for a while, initially just to play mp3’s. Then I got an iPod, and the need for bogomips speed became less pressing.

With the new car, I had no tape deck .. so hacking was required to add a line-in (by way of FM modulator) to connect my external digital audio device. In the course of this hacking, I discovered it’s fairly simple to take apart the interior of a Mazda 3 (see my links for some hints). So ideas and possibilities started popping into my brain .. “I could put the GPS under this panel here .. and the wires would go here”.

Also, there’s this nifty device called the “AuxMod”: .. which provides a much cleaner line-in than a modulator. And the Advanced version adds a serial port for some nifty interfacing to the OEM head-unit — the buttons on the steering wheel could control a PC, and the PC could send text to the in-dash display ..
more ideas 🙂

Anyway, I finally started this weekend. I pulled off a few plastic panels and put USB WiFi adapter and a GPS receiver under the dash, right behind the defroster vent. The actual computer (case+board+DC-DC power supply) is still on the way, but I’m planning on sticking it right under the driver’s seat. I already have the USB and audio cables under there, ready to plug in. I also stuck an open USB port where the ashtray used to be.

Once I get the PC in there, I’ll start playing with the software.
OS will be Linux of some flavor (probably “Debian”: or “Ubuntu”: ) .
“MPD”: has worked great around the house as a headless music player, should work well in the car too.
Still looking for a GPS program that will work well with a text-only display (or no display). Some simple track logging should be pretty easy to set up though.

Other possible hardware:
bumper mounted digital camera(s) – you’d be surprised how hard it is to accurately remember the license plate number of a hit-and-run driver 😛
OBD-II interface – think /var/log/car_engine 😀

Case and PC should be arriving this week, I’ll post more after I have it installed .. *evilgrin*

headphones and felines

A cautionary tale for cat owners. Hide your headphones! (yes, this is a blog post about cats 😛 )

A certain cat at our house (who shall remain nameless … except for “Furry B&%#!@$!”) has developed a taste for headphone cables.

The first time it happened, I had just bought a new pair of Sony earbuds .. I forget the model, but they poke into the ear canal a bit more than most earbuds. They had a weird rubberized cable that was hard to bend or coil too tight, making the cord less tangle-prone. However, this rubberization did nothing to protect agains cat teeth. I woke up one morning and found them on the floor next to the bed, the plug-end completely separated from the ear-end. %&$!% The cat was lucky to live through the day. Since this was the first time the Cat had eaten any earphones and these were a new pair, I suspected there was something tasty about the special rubberized cables.

I made another pilgrimage to Fry’s, where I bought another pair of earphones. A different pair. Sony MDR-EX51’s to be exact. I know because I still have them and use them. But no, they did not escape the Jaws of the Cat. I was more careful and made sure to keep them in a backpack or on a table, but tables are no match for The Cat. Again, one morning after getting out of the shower, there were the headphones on the carpet next to the bed … all in one piece, this time, but with a throrougly chewed spot in the cord midway between plug and earbuds. *&^$!@$ing *&(@#% CAT! Tested them .. no sound, at least one wire completely severed.

You’d think I’d learn, but no, I went back and bought another pair (of the same kind this time). Promised myself I’d take extra precautions, never leave them anywhere in reach of cat teeth. And I tried, I really did. Yet again, one morning (why is it always in the morning?), there’s The Cat, headphone cable in mouth, chewing away. %!@#%&‘ing !#%*&% CAT *#&@^er!

So I dug out an old pair of slightly uncomfortable but cheap and easily replaceable earbuds. The Cat recently devoured these as well, gnawing through the cord to only one earbud this time, leaving me with a working but now monaural headphone.

I took the remains of Headphones III (or Headphones II? one of the nice Sony’s, anyway) and soldered on a new plug. They work fine now and still sound great, but whatever they’re plugged into has to stay in my hand or shirt-pocket, with the cable now half of its original length. I am keeping them out of reach of the Cat.
I also found and purchased at Fry’s a more comfortable pair of five-dollar earbuds made by Phillips. The Cat has not eaten them, yet.

But this is not the end!
The Cat, being deprived of his headphone-cable-based nourishment, decided to go after … well, let’s just say The Cat is probably in cahoots with “this dog”: . The Freaking Cat chewed through the power supply cable to my iBook. (Un?)fortunately, he managed to eat the cable without electrocuting himself, possibly because he’s smart enough only to chew on the DC cable instead of the one plugged into the 120V mains.


I may need to try this watch .. I usually have an awful time getting out of bed in the morning .. the clock-radio alarm only provides a soundtrack to whatever I’m dreaming .. and annoys the heck out of Natalie. Somehow, on our camping trip last week I managed to get out of the tent by 7am each morning (!) ..

more on the trip later

What an incredible smell you’ve discovered!

So I walked into the computer room/office and was hit by the unmistakable smell
of broken electronics. Natalie came in and smelled it too, said it was
stronger over by the PC (not the server) .. I notice it’s a bit quieter than
normal — not silent, but quieter. She put her hand behind the case and says
the back is really hot, and there’s no air coming out. oh, yay, dead power
supply fan. The processor fan was fine, accounting for the remaining noise.

Oh well, good excuse to go get a new super-quiet power supply 🙂

Regarding pointing devices and laptops ..

So right before I broke down and got this Mac, I claimed I liked eraser-heads better
than touchpads
. I think I my opinion has now reversed. After using the
iBook for about 10 months, I’ve actually gotten used to the touch pad on it.
It’s definitely lets me move the cursor around faster than the little red
nubbin on a ThinkPad. And being able to just thump the pad rather than
actually click the button is nice. I guess I was comparing the traackpoint to
the touchpad on the PC laptops I’ve used — I still don’t like those much.
They Mac touchpad is somehow different. Also, it seems to work best when my
fingers are very dry.

But an actual mouse still beats any built in pointer.

About my other complaints with Apples … some of the PowerBooks have
PCMCIA slots I think. One button is still annoying .. Ctrl-click instead of
right-click? 😛 But an external USB mouse works fine. No IrDA’s a bit of pain
but not really a big deal. A few times, it would have made it easier to get
files from someone else’s Wintel laptop to my iBook, but a CF card and reader
worked fine. And Bluetooth is working ok for syncing my phone (just not
copying multiple files off of it). Still have to use a cable to sync my Visor

As for the serial port,
I returned the non-OS X-supporting IOGear dongle and got a Keyspan one instead (for
$5 more). It has drivers for MacOS X and Linux, as well as Windows.* … works great with my Garmin GPS and MacStumbler 🙂

We regret any inconvenience ..

If you happen to have an iBook running Mac OS X and also happen to have a GPS
with a serial cable, and you think to yourself, “Gee, Self, wouldn’t it be nice
if I could use my GPS with my iBook?” .. and your self replies “Yes!”, so you
decide to go to Fry’s, and if while you’re there you see the IOGear USB
PDA/Serial adapter, tell yourself not to buy it, even if it’s the only
USB-to-serial device they have in the store. The packaging, in this case, is
not out of date or incorrect: “Supports Mac OS 8.6 to 9.x” (as well as every Windows version) — suspicions confirmed at

We regret any inconvenience this may cause you; however, at this time, OSX is not supported for that particular product.

The inconvenience here being the drive back to Fry’s to get a refund for their useless dongle product. I don’t (yet) have any PC’s without a serial port, or any old Mac’s with USB..

Finally …

a decent looking portable MP3 player that can also record straight to MP3.
There’ve been a few others out there, like that Archos thing (a bit to big ..
and ugly 😉 and that other thing (can’t remember the name, but it only has 128
megs until you snap on the extra hard drive module). It looks like
Philips has done it right with the HDD100 .. 15GB,
USB2.0, in-line remote, and it records :-).

Oh, and they’re looking for beta-testers 😀

(via Gizmodo)