Storms, Crustaceans, and PQFP Chips

There’s a major thunderstorm passing overhead right now. The noise from the rain hitting the roof of our building sounds like loud applause. Ten minutes ago it was warm and dry outside but that’s Texas weather for you. I’m working late again tonight and I’ve been nervously watching the lightning strikes all around the area and hoping one of them doesn’t take out our power. I replaced the batteries in two of our UPS units this month, so we’re probably ready for it if it happens.

Susan is working late too. We took a little break earlier and tried another of the new restaurants that’s opened here in Deep Ellum. There seem to be new ones opening all the time. Tonight we tried Crustaceans, a creole/cajun place. It’s actually the reincarnation of a New Orleans restaurant that was destroyed by hurricane Katrina. The owner, chef, and some of the employees ended up in Dallas and a local organization helped them re-open their restaurant here in Deep Ellum. It’s the real thing. If you’re in the area and like that sort of thing, definitely check it out. In the past week we’ve also tried Tarantino’s (Italian food, a bit expensive but very good) and Kim’s Cafe (breakfast, burgers and sandwiches – so so).

The website design business is booming lately, leaving me not very much time for more fun things like robotics. The latest group robot project at the DPRG is proceeding nicely without me. I’ve been working on my own robot off and on. Just as I finally felt like I’d wrapped my head around PID algorithms and got some working code, I managed to toast the 68332 on my MRM board. I’m guessing it was a static discharge. It’s a surface mounted 132 pin PQFP chip; not exactly something you can replace with common household tools. I ordered a few new chips, though, and a friend with a hot air rework station is going to swap out the bad one for me.

Robonexus 2005 Debriefing

I’m finally getting caught up on things since returning from Robonexus and one of the last things on my ToDo list is posting something here about the trip.

Before I get to that, I should mention that Susan and I went to the State Fair of Texas this year just prior to my Robonexus trip. Nothing new and amazing to report there but I used the Fair to test out a new camera, the Fuji Finepix A345. The A345 is an inexpensive 4.1 Megapixel pocket camera. I still shoot a lot of 35mm film but didn’t want to lug my Canon T90 and associated gear around Robonexus, so I picked up the Fuji to try out as an alternative. If you’re curious, take a look at a few of the 2005 Texas State Fair photos or the Robonexus photos I shot with it.

Okay, so on to the Robonexus trip itself. Like most trips, it started with the hassle of airport security and placing all my belongings into little plastic bins. I filled one bin with cell phone, camera, keys, change, belt and shoes. It took another for my laptop and a third bin for the laptop case. This was followed by some hopping around on one foot while trying to put on shoes and simulatneously hang to my other stuff so it wouldn’t get stolen.

I’ve been to a lot of places in California but this was my first trip to San Jose. Random San Jose info: It doesn’t look that different from the Dallas area. They’re still using incandescent traffic lights instead of LED lights. The cross walks emit all sorts of weird sounds that are presumably intended to assist the blind. We’ve got nothing like that here in Dallas. The Kinko’s in San Jose have service as bad as those in Dallas.

I ended up in Hotel Montgomery which is within easy walking distance of the convention center so I didn’t need a car. I got in on the first day and picked up two sets of credentials: a press pass as editor of and an exhibit staff pass for the Dallas Personal Robotics Group. Because the DPRG didn’t really have enough advance notice to prepare anything interesting, we ended up just placing some flyers on our table that described the group. I had the flyers printed down the street at a Kinko’s (see above comment on Kinko’s).

I only had time to sample a few of the talks including Matt Mason’s overview of robotics and AI research at CMU, Michael S. Chester on launching a robotics company, Max Chandler on robotic art, and Stewart Tansley on Microsoft’s plans in the field of robotics. I showed up to hear Phillip Torrone of MAKE but he was a no-show. Most of the talks were interesting but primarily technical in nature. One non-technical talk, Joanne Pransky on The Frankenstein Complex and Its Impact on Robotics, brought up more philosophical subjects such the human reaction to robots with intelligence, emotions, and sentience. The talk left a number of people, including myself, involved in debates with other audience members over the subject. Some people still seem to be made profoundly uncomfortable with the idea that machines made of metal and silicon may one day be as good as us meat-based machines at thinking and feeling. No mob of angry peasants with torches appeared however, so perhaps things have improved since Frankenstein’s time?

Along with several other Dallas attendees, I escaped the conference for a few hours on Friday and drove up to Stanford. Sanjay Dastoor, a DPRG member who is now a student at Stanford, arranged a tour of some of the robot labs for us. We checked out the Stanford quadruped and also got to see some of the Stanford Sprawl robots in action (they’re fast!). After the robot labs, we took a few drive-by photos of the Frank Lloyd Wright Hanna House which is on the Stanford Campus. I also got a chance to check out the San Jose Museum of Art since it was just across the street from the convention center, though I had to do that one by myself. It was worth the visit and I enjoyed the Sandow Birk exhibit in particular. Overall I’d say it rates higher than the Dallas art museums but not as high as the museums in Ft. Worth.

Back at Robonexus, I spent a lot of my time networking. It was good to meet so many people in person who I deal with online regularly including most of the fine folks at Servo Magazine. The conference includes an interesting mix of high-end commercial robotics companies such as iRobot, commercial hobby robotics suppliers such as HiTec, and non-profit organizations such as the Robotics Society of America. There were also demos of many robot contest formats including NATCAR, Botball, FIRST, Robo-Magellan, and the Trinity Fire-Fighting competition. One suprise this year was the arrival of Lindz Lawlor and his Electric Giraffe. The Electric Giraffe is a huge mechanical quadruped equipped with more lights and audio amps than your average dance club. It walked around belting out dance-velocity Kraftwerk tunes. The Electric Giraffe was created for Burning Man, which seems to be a venue increasingly used by robot builders to demonstrate their work. After talking to Lindz and others who’ve been there, I started thinking it sounded like a lot of fun.

I returned to Dallas from Robonexus with two general feelings. The first was that the DPRG needs to go to Robonexus 2006 with more people and plenty of hardware to show off. The second was that the DPRG needs to think about creating something worthy of Burning Man. Interestingly, I’ve discovered that when you mention attending Burning Man, people will either react by saying something like, “What?! Burning Man is jest a bunch of nekkid hippies runnin’ around!” or they’ll say, “I’ve always thought Burning Man looked like fun but I’ve never had a good reason to go”. The DPRG members seem equally divided but I wouldn’t be suprised if we manage to make it out there in the coming years.

Robonexus, Here I Come

I’ll be leaving for Robonexus in San Jose Thursday morning. I’ll be out there until Sunday. I plan to have fun, take lots of photos, cover the show for and maybe do some coverage for Servo magazine as well. In addition to myself, Roger Arrick of and Arrick Robotics will be going as will several members of the Dallas Personal Robotics Group. We’re hoping to take some time to tour the Stanford robotics lab and whatever else we can find to do. If there are any other robot folks or free software/open source people in the area who’d like to get together, let me know.

Random News from the Month of May

Yesterday Susan and I braved the scattered rain to attend Dallas Artfest 2005. It turned out to be overcast and cool but only a tiny bit of rain fell. Susan found some interesting jewellery and it made a nice break from work.

I’ve been working with David Anderson in porting his robotics library for the MRM board to gcc 3.4.3. I’ve added a little code of my own in the process and I’m using Doxygen to produce pretty web-based documentation for the whole thing. We still have a ways to go but I’m hoping to release the completed library as a DPRG project in a month or two (under GPL of course).

We saw Hitchhiker’s earlier this month and found it sadly disappointing. It appears to have been adapted to the big screen by people who had no clear understanding of Douglas Adams brand of humor (or British humor in general). It almost appears they didn’t understand it was supposed to be a funny story and tried very hard to turn it into an action movie by excising anything remotely amusing from the script. Even worse, they frequently removed the setup for jokes but left in the punch line or left in the setup and removed the punchline, making the story incomprehensible (or at least very non-funny) for those who hadn’t read the book, heard the radio version, or seen the TV adaptation. The one redeeming moment was when the real Marvin made brief cameo appearance. I suspect everyone reading this has seen the movie by now but if you haven’t, save your money and buy the very nice DVD of the BBC television version which is a lot more fun.

We also saw Revenge of the Sith. What can I say. At least it’s finally over. It was better than the last two but I’m afraid the original version of the first movie is the only one that was really fun as a stand-alone story.

I’ve had some time to start working on mod_virgule again. My highest priority is porting it to the Apache 2 module API so I can finally ditch Red Hat 7.3 on the box. I’ve almost got a clean compile but it’s going to take a little while to get it debugged and stable before I switch over.

Robots, robots, robots

Between the recent office move and keeping up with herds of cats, I’ve fallen a bit behind in reporting news in other areas. Work is still progressing on the Ultracap power supply. After some further testing of the cell-balancer circuit based on the TI TLV4112IP high-output-drive op-amp, I decided that, while working flawlessly otherwise, it was drawing too much current. I’ve been rethinking the need for dynamic cell balancing and have re-read a lot of the Maxwell technical documents. My new theory is that balancing may not be as essential as I originally believed in a very low current application such as a robot power supply. I now think it may be possible to get by without dynamic balancing provided I protect the cells from over-voltage conditions during the charging cycle with something simple like some zener diodes. Finding very low voltage zener diodes proved a bit of challenge but I finally found some 2.7v 1/2 watt devices made by Fairchild that may work. I’ve ordered a few and will post results of the new tests soon.

Meanwhile, the DPRG received word from the IRS that our application for 501(c)(3) status has been approved, so we’re an official not-for-profit corporation now. And it only took 20 years to get to this point. I missed a couple of weekly meetings because of the move and during that time, Ron and some other members have been working on the A/C compressor at the warehouse and managed to getting it running, so we should have cool air for the next few meetings. We may have heat too shortly, which will come in handy in a few more months.

Cats, Caps, and Contests

Ultracap Update

After prototyping a cell-balancing circuit for my robot power supply based on Maxwell 350F Ultracaps, I discovered the original choice of the TI TLC25L4CN low-voltage op-amp was not a good one. The little chip just couldn’t deliver enough current to balance the cap voltages in any reasonable amount of time. The peak output of the prototype was about 4 ma. So after spending a couple of hours searching for an op-amp that could operate at low voltage and put out a substantial amount current, I came up with the TI TLV4112IP high-output-drive op-amp. At last week’s RBNO, I built a second prototype and… it works! The new op-amp outputs up to 300 ma easily. Using the test circuit, I set it up with one Ultracap at 1v and the other at 2v. In little over a minute, the system balanced with both caps at about 1.6v. Next Tuesday, I’ll put together a more complete prototype with four Ultracaps and three cell balancers.

The cell-balancer has also proven to be a good way of trying out the GPL Electronic Design Automation (GEDA) package. I’ve been using the schematic capture program gschem primarily (screenshots) and have been asking lots of stupid, new-user type questions on the mailing list. They’ve been very patient with me so far and I’m begining to get the hang of it. It turns out good-looking schematics. Once I finalize the power supply, I’ll post a link to the GEDA files for anyone who might want them.

Cats in the garage

The abandoned mother cat and two kittens we brought home a few weeks ago are still with us. We know a lot more about them now. The kittens were much younger than we first thought. We’ll probably hang on to them until the kittens are a bit older. Susan has settled on names. The half-siamese mother cat is Sophie, the black kitten with the missing toe is Zippy (though she insists on spelling it “zippie”), and the tailless calico kitten is Callie. No luck finding a home for any of them yet. Callie is probably too emotionally disturbed to make a good pet but we have located a group called Barn Cats International that assists with finding homes for problem cats on farms and ranches where they can live with minimal contact with humans. Hopefully we’ll be able to find good homes for the other two. If anyone in the Dallas/Ft. Worth area needs a cat, let me know!

Nigritude Ultramarine contest outcome

The contest ended on July 8th. Thanks to everyone who linked to my site, especially, Bram. His link resulted in more hits on my site during the contest period than anything except Google itself. Feel free to remove those links now. I’ll probably leave the page up until the domain expires. I ended up in position 6 in the final results. The winner was a blogger who apparently won primarily through old fashioned Google bombing. Oh well, my site received a sort of honorable mention prize, the Judge’s Choice Award. My prize is one of those teeny, tiny “James Bond Stealth digital cameras” like you see on ThinkGeek. I’ll post a photo as soon as I get it talking to my Linux box (it only comes with Windows software but it has a USB cable so I’m hoping I can just mount it like a little USB drive).

We’ve been pretty busy at the office doing website design jobs. The lease on our office space is up soon and we’re deciding whether to stay put or move to new space. Even if we move, we’ll stay in Dallas and probably in the same general area.