A Few Fun Things

It’s way past time to catch up my readers on what we’ve been up to lately. Since my last post we went to the La Reunion winner announcement party for their Make Space for Art architecture contest. While there we heard a really cool music ensemble that called themselves the Escalator Maintenance Society. In addition to a cello and bass, they played an amplified mechanical typewriter and a child’s toy piano. It was some fun, minimalist-sounding music. After the event, I ran into the manager of Club DaDa outside and she said the group would be playing there soon. We’ll probably go hear them again if we can work it out.

We also went to the Dallas House of Blues for the first time to hear They Might be Giants and Oppenheimer play. I’d previously been to the Las Vegas HoB and spent a lot of time in the Foundation Room there hanging out with bizarre local characters. We weren’t lucky enough to know anyone with Foundation Room access here but still had a good time. It’s an interesting place and a pretty good mid-sized music venue. We got the cheap tickets for the standing-only area near the stage but it turned out there are a couple of bars near the back and we managed to snag some bar stools there. It was further away from the stage but the view wasn’t too bad. As is frequently the case, the audio was mixed so that the instruments were 10 times louder than the vocals so you couldn’t make out any words. For some bands that’s not a problem but TMbG’s music is largely about the humor of the lyrics so it was a bit disappointing.

Last weekend, I went to All-Con 2008. The Dallas Personal Robotics Group was invited to display and do some demos so I went along to take photos. This was the first science fiction convention I’ve been to in many years and it was a lot of fun. There were all sorts of robots to be seen. Aaron Douglas (Chief Tyrol of Battlestar Galactica) was one of the guests, and I suppose we can count his character as a robot too. There was a fun demo by the Assassination City roller derby girls, a local group that does flat-track roller derby. I was also surprised to see the Lollie Bombs there. The Lollie Bombs are a Deep Ellum burlesque troop and this was the first time I’d seen them. Also a lot of fun. I met lots of other interesting people and posted a flickr set of All-Con photos. I stayed out way too late and ended up coming down with a cold the following week, probably from some alien bug I caught at All-Con.

A Programmer Learns to Weld

That’s right, I’m taking a welding class. Some fellow DPRG members found the community education class and were getting a group together to take it. Granted, welding isn’t a skill I generally need in my daily routine but it intrigued me enough to join the class. It might come in handy if I find the need to create a giant robot, or a big metal dinosaur for the front yard.

The first day of class was spent on the use of a fuelgas welding rig to cut and make holes in metal. Practical lesson #1: sparks fly everywhere and, while they’re harmless if they hit your skin, they have deleterious effects on some types of clothing, like those cheap hoodies you find at Sam’s Club that are covered with a thin later of fuzzy stuff. The sparks create mysterious little craters in the fuzz. Practical lesson #2: if you’re wearing non-leather shoes, watch out for blobs of molten metal falling on your feet.

International Space Development Conference

As I write this, I’m sitting at the DPRG’s booth at the International Space Development Conference. The ISDC asked us to be an affiliate and demo some robots. In the next booth is a group of high-powered rocketry people who have some rockets about 15 feet tall. John Carmack’s Pixel lauch vehicle, built by his Armadillo Aerospace group, is sitting on the floor about 20 feet in front of me. Carmack and his engineers were here yestereday. I’ve also spotted a few other interesting people wandering around; Ben Bova and Buzz Aldrin. Larry Niven was supposed to be here somewhere but I haven’t seen him yet.

There are also loads of non-profit space colonization groups here. I remember 20 years ago at science fiction conventions seeing groups like the L-5 society asking for donations so they could colonize space. I optimisitcally became a member of several groups. Eventually I realized they weren’t really doing anything. After all these years, they still haven’t gotten any further than sitting at tables and telling people about how great it would be to colonize space. The names have changed. Apparently, the L-5 Society is defunct now. In it’s place we have groups like the Mars Foundation and some Moon Society. I talked to the people at a few of these and they seem to have the same strategy of achieving their goal by talking about it endlessly. It’s kind of depressing. They all seem to ignore the basic problem that it’s expensive to get into space to do all this colonizing. If they spent a little time working on that, they might get somewhere.

Stories of Coincidental Electricity

The annual Tanner Electronics Robot Show was on Saturday, April 14. The DPRG held their annual robot talent contest concurrently. So, not suprisingly, I was planning on working late the preceding Friday to get my new little robot, Robozoa, into shape. This mostly involved finishing some hardware-related things like wiring from the H-Bridges to the motors and from the motor encoders to the microcontroller. This sort of work is better done at the DPRG Lab where there are plenty of tools and test equipment to make it easy.

The weather prediction was for rain in the evening, so my plan was to head up to the DPRG immediately after work. Not suprisingly, a last-minute work-related emergency held me up for a couple of hours. By the time I was finally able to leave, a torrential rain had started. When a break in the rain materialized, I ran out to my car; only to get a phone call before I was out of the parking lot. The call was from Susan, who was holed up at home in a bathroom with the three cats because the TV had just announced a tornado was headed her way. She said the tornado watch area extended to the downtown area where I was, so I decided I’d be better off inside the office than in my car until things calmed down.

I ran back through the now heavy rain into the office. As I dried off, I clicked up a few weather radar sites. Sure enough, there were some nasty looking thunderstorms headed my way. They passed over Irving, where Susan was, without any serious damage resulting (it’s now unclear whether the reported tornado really touched down or not). The worst of storms were now north of Dallas in the Garland area, where the DPRG Lab is located. I decided to settle in and do what work I could on the robot at the office. I finally left about 1am by which time the rain had stopped. I was a little annoyed that this series of events had kept me from making it to the DPRG where I could have worked more efficiently.

The next morning, I showed up at the Tanner’s event. The previous night’s storm had brought with it a freak, one-day cold front. Despite the cold, a fair number of humans and robots showed up to participate. But, more interestingly, several people said they’d seen the DPRG’s building in Garland on the news. There were firetrucks in the parking lot. Apparently it was hit by lightning. Eric Sumner, Ed Paradis, and I decided to drive up to Garland and check out the damage.

From what we could tell, the lightning hit the transformer immediately behind the DPRG building. It largely destroyed the power line between the transformer and the building, reducing it to a series of short fragments. The power meter was completely destroyed. The charred metal casing of the meter was still on the wall, surrounded by blackened bricks. The transparent housing and meter electronics, or the remains of them, were found on the ground. The meter had contained several boards with surface mount components. The lightning blast had desoldered all the components and completely vaporized many of them. Inside the building, the main breaker box was also a charred mess but it appears the breakers vaporized so quickly that it limited the damage to the downstream breaker boxes.

By Tuesday power had been restored and we were able to evaluate the damage. Remarkably, the only losses discovered were a single surge protector and one very old dot matrix printer. Aside from those two casualties, test equipment, networking gear, computers, all seemed to have survived no worse for the wear. All thing considered, I’m glad I wasn’t around Friday night when it hit.

Random Free Software Stuff

Subversion

One of my longer term ToDo items made it to the top of the list this week. I’ve been setting up a Subversion repository for the Dallas Personal Robotics Group. The DPRG has a number of programming projects in various stages of completion ranging from working code to idle talk. Having a repository like Subversion will make project development easier, particularly for projects with multiple programmers. All projects hosted in the new Subversion repository will be Free Software and/or Open Source.

I used Subversion v1.3.2 for the initial setup. ViewVC v1.0.3 was added to provide a web-based interface to the repository. Last, I added Highlight v2.4 to provide some nice code highlighting for the ViewVC code browser. Everything is running on a CentOS Enterprise Linux box that also hosts the DPRG website.

At this point, everything seems to be working but I still need to customize the ViewVC templates to tie the look-and-feel in with the main DPRG site.

In addition to DPRG projects, I’m going to keep the mod_virgule codebase there too. Mod_virgule is the code used on robots.net and Advogato. Getting mod_virgule into Subversion was a good learning experience. I used the trunk, branches, tags layout recommended by the GPL’d O’Reilly Book, Version Control with Subversion. I used the last 2004 release of Raph’s codebase, version 1.41 as the initial commit. I created a separate branch for Raph’s code and also tagged it as release 1.41. Then for each of my releases since 2004, I committed them and tagged them as a release.

Ubuntu and Proprietary Drivers

Seems like everyone has been talking about Ubuntu’s decision to start including proprietary graphics drivers in the Distro to support flashier eye candy on the desktop. There’s been a lot of discussion and some flame wars over the issue. Rather than joining in flame wars, how about an an alternative? Why not put that energy into making sure there are free drivers for ATI and nVidia?

There are currently free ATI drivers with DRI support for 3D acceleration. Maybe someone could find out why the free driver is not suitable for the Ubuntu folks? Not fast enough? Missing a critical feature? Maybe it can be improved enough that the Ubuntu developers would reconsider their decision.

The free nVidia driver doesn’t support DRI so there is no free alternative yet for nVidia cards. The nouveau project is working on the problem. They’re making fast progress but they could use your help. They’ve developed a tool called called REnouveau to assist with reverse engineering the nVidia hardware without violating the license on the proprietary driver. If you have an nVidia card, you can help by downloading the proprietary driver and using this tool to generate dumps of test data for your card.

For a few more ideas on how you can improve Free Software support for 3D accelerated graphic cards in general, visit the Free 3D wiki.

Robots and Linux

What free time this month wasn’t sucked up by the Advogato migration was spent working on Tankbot GTR, the current DPRG group robot project. We now have the Mini-ITX mother board that Via donated mounted on the robot. We were doing our initial testing with an old 800MB laptop hard drive but it really sucked the batteries dry quickly. So I picked up an IDE to CF adapter and Martin donated a 1GB CF card. For the moment, I just used dd to move the entire hard disk content to the CF card. This is working surpisingly well considering we were running an old Redhat 9 distro intended for the desktop.

While most distros offer bootable CD images of one sort or another, almost none offer bootable CF card images. Many provide overly complex instruction on how to get their distro to boot from a CF card but few provide something as easy to use as a simple image file that you can copy and boot. Once exception is Flash Puppy, so I’ll probably be experimenting with that later this week. I’m begining to think there might be a real need for an embedded linux distro targeted at robot applications. And one that’s as easy to install as copying an image to CF card, sticking it in a motherboard, and booting.