The Deliverator – Wannabee

So open minded, my thoughts fell out…

Archive for February, 2006

Time flies when you are having robots

Posted by Deliverator on 11th February 2006

As Eric noted today, “time flies when you are having robots.” We now are a scant week and a half till ship date.

We met up today at Larry’s to work on the build. Finding an effective stir mechanism for an open hopper design has proven difficult, so we started to prototype a new design that keeps all the balls in jam-proof rows. This will be limiting in a few ways, but I don’t think overly so. We worked out a test feed that seems to work well. Tomorrow, I am going to head into Seattle and try and pick up the parts we need for our new feed design, so that we can build it on Sunday.

Larry put together a new chain to replace one of the drive train chains that broke, recently. The #25 chain that we are using, in combination with the smaller sprockets we are using has resulted in a lot of stretching. Larry also found a bit of code that was producing twice as much torque as normal. I am going to order some fresh chain, so that we can make some spares. If we have enough time, hopefully we can swap in some new, unstretched chain right before the competition. Breaking a chain during competition would not be good, although with our six wheel drive train, we could still manuever.

After the build, we hauled the robot over to school and let the drive team have their fill of driving the robot around on the carpet. We then did a little work on refining our prototype ball feed mechanism. After that, we tested out rolling balls in from various locations on the floor. We found that we could score better than 80% of balls from the starting position and close to 100%. To achieve 100%, we released our two columns of stacked balls sequentially instead of concurrently and we released the balls into the roller only once it was fully spun up, instead of letting the roller itself initiate the feeding. In short, to shoot 100% from starting position, we would need some sort of gate release mechanism to drop the two colums of balls into the roller. This is an additional system to build and time is getting short. We found that if we moved up a mere 10 feet and then release, we can make 100% without needing to do anything additional to the mechanism. KISS!

After playing around with the feed for a while, we ordered a pizza and Ryan began doing some autonomous coding. The first few runs weren’t so successful, but later autonomous code worked much better. With luck, we will have a versatile set of autonomous modes with which to impress potential alliance partners. For a few laughs, check out the videos.

As usual, these videos are encoded using the XVID codec, which you will need to view. You can download XVID here.

Some pictures of today’s activities are available in my gallery.

Posted in General, Tech Stuff, Titan Robotics Club | 5 Comments »

Robot Update – 020906

Posted by Deliverator on 9th February 2006

Tuesday’s build meeting was not as productive as I had hoped. We are getting hung up pretty hard on the feed mechanism. Larry and Dave are still trying to come up with a mechanism to break up the ball-jams that occur with an open hopper design. I feel like we have wasted much too much time trying to troubleshoot this issue and should have moved on to other things at this point. Everyone is getting pretty stressed out. Hopefully we can settle on a design tomorrow and finish it Sunday. It is now a week and a half till ship date.

Today I met with Ryan’s dad, Jim, and a couple of kids to discuss our plans for video and camera footage at the PNW Regional competition. We hope to have much better footage this year, by design, and to use it to provide strategic feedback for the drive team and for future promotional materials. Once I type up the meeting notes, I will try and post them here.

After the video meeting, Ian went off to Larry’s to fetch Hoenir (this year’s robot) for some driver training. We unrolled some carpet, taped out starting field positions and put up one of the side goals. Much to our pleasure, we found that we could roll balls in from the starting position. We may be able to score 10 points in autonomous without ever having to leave our starting position! We can also roll balls while moving forward at speed, so we should be able to score on the side goals without too much risk of getting rammed (a sitting target is an easy target). Bruce Welti came by to try and do some autonomous programming, but had difficulty setting up the build environment on his laptop. Hopefully he will come to tomorrow’s meeting and Larry can help get him set up.

Here are some pictures of Tuesday’s build meeting and today’s drive team meeting. For the moving picture minded among you, here is a video of the robot scooping balls off the floor.

Posted in General, Tech Stuff, Titan Robotics Club | No Comments »

The Interweb, coming soon to a virtual world near you!

Posted by Deliverator on 9th February 2006

I was browsing DougT’s Ramblings for news of progress on Minimo, a paired down version of Firefox for mobile devices running Windows CE and Linus. DougT is the project’s chief developer, and development on Minimo seemed to be slowing down a bit. His latest blog entry reveals the cause of the slowdown. Turns out he has been hard at work figuring out how to embed Firefox into Second Life. Embedding a web browser within Second Life is quite a technical feat and one that will undoubtedly revitalize interest and in-world development. Embedded browsing has been on the Second Life Developer’s Roadmap for quite a while, but has been repeatedly pushed back. The first release was supposed to be simply displaying the output of a url on a texture mapped on 3d object, with no ability to interact with the displayed pages. DougT and his Linden Lab buddies seem to be overshooting for their 1.0 release. An example application called uBrowser lets you fully interact with a Firefox web browser mapped onto an OpenGL object. You can click on links, fill out forms, etc. The ability to work with data sources mapped onto 3d objects is incredibly exciting to me. It is really the first step towards computer mediated reality, with the Interweb transitioning from being a seperate cyberspace to being a layer of data overlayed over the real physical world.

Firefox OpenGL

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WordPress 2.01

Posted by Deliverator on 6th February 2006

I just upgraded to WordPress 2.01, only a few scant weeks after upgrading to The new version fixes a number of important bugs and also some issues with composing entries using the new integrated wysiwyg editor. I definitely noticed some of the problems with the wysiwyg and switched back to the old editor style, for now. I also upgraded some WordPress Plugins. If you see any oddball behavior, please notify me.

Posted in Blogging, General | No Comments »

FRC Build Meeting – 020506

Posted by Deliverator on 6th February 2006

Sunday, we had a small, unofficial build meeting. The meeting was officially canceled due to the Seahawk’s participation in the Superbowl. Larry, Dave, Ryan and I spent the morning playing around with different hopper designs. Both the shooter and roller mechanisms will eject balls as fast as they can be fed. I took a few videos and in one of them, our roller ejects 13 balls in 1.1 seconds. The trouble, as predicted, is jamming. 7″ foam balls just love to jam. I think we are either going to have to use a hopper design that lines up the balls in a row, or have an open hopper design with some sort of stirring mechanism to keep balls flowing to the mechanisms. An open hopper design would be preferable, due to greater holding capacity, but we really had a devil of a time getting one to work consistently, yesterday. Tomorrow, we will be meeting again and we will see what we can come up with.

Here are pictures of yesterday’s hopper prototyping session

Videos of our machine gun roller are available here and here. The videos are encoded with the XVID codec, so you will need to download and install the codec, if you don’t already have it on your computer.

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Mini-media center almost complete

Posted by Deliverator on 6th February 2006

I moved the guts of my mini-media center into a new case. The new case is a Travla C138 in black. It is pretty much the smallest case available that accomodates a PCI slot. It is very nicely machined with no sharp edges and has a nice handle on the back for carrying it. The case has space for a slimline optical drive, 2.5″ or 3.5″ hard drive and has breakout ports for firewire, 2x usb 2.0 and audio connectors at the front of the case. The PCI slot can only be used if you are using a 2.5″ hard drive (a 3.5″ blocks the slot), so I will have to clone my existing drive onto a notebook sized hard drive in order to use it.

I am currently thinking of adding either a ATSC HDTV TV tuner card or a Siig USB 2.0+Firewire+Gigabit Ethernet card. I have put these Siig cards in a number of older computers. USB2+Firewire cards are a dime a dozen in the industry, but imo, Siig makes some of the best oddball i/o cards around. Another possibility is to add a PCI wireless card. I still need a higher bitrate solution for ferrying video than the current 802.11b gear is capable of providing.

To top off the system, I added a RF wireless keyboard made by BTC. It has a mini-joystick for controlling the pointer and well laid out auxilary+media keys for common function like scrolling up/down. It is quite ergonomic and fits comfortably in one’s lap while lounging on the couch. Each side of the keyboard has a easy to grasp handle. The keyboard communicates via RF, instead of infra-red, so it has much better range than your average wireless keyboard. I have tried a lot of wireless keyboards, and for home-theater use, this is one of the few that I would recommend. The only other wireless keyboard I can whole-heartedly recommend for home-theater use is the Adesso WKB-4000 US. It has incredible range and is quite small, which is handy when dealing with coffee tables already overflowing with remote controls. If you are in the market, I recommend checking these two out. They are really better than anything I have used, including the incredibly overpriced line of RF keyboards from Gyration.

BTC Keyboard 32 Travla C138

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FRC Build Meeting – 020306 (awesome videos!)

Posted by Deliverator on 3rd February 2006

Arrived late to today’s build meeting. Had to earn money for a change. Larry and da kids had the roller mechanism nearly completed by the time I arrived. We got the shooter’s motor remounted to a position on top of the shooter instead of in front, to give us more space for the ball feed mechanism/hopper. Larry coded a callibration routine that maps the output range of the FIRST microprocessor controller to the full output range of the Victor motor speed controllers. This will hopefully let us drive the motors across their full possible range of speeds. We reassembled the frame and loaded the robot, now quasi-officially named Hoenir (aptly named after the Norse god of indecision), into the back of Cheuk’s mini-van to haul to school.

When I arrived at school, Ryan was hard at work with the drive team (and hangers on). They have been practicing with last year’s robot, Tyr, which has a very similar drive train. In particular, Ryan was working with Erik to produce code for using a strearing wheel for drive train control, instead of a joystick. We saw several teams that used this type of system very successfully last year and decided to try it on this year’s robot. Ryan got Larry’s code dump with the new calibration routines and managed to add his code for stearing wheel control. We then ate Pizza, after Dominos finally decided to believe that the International School was extant.

After Pizza, we improvised a ball hopper out of cardboard and hauled in a ramp/slot from outside. We loaded the hopper with 20-30 balls and let her rip. The result left us jumping up and down and dancing, dancing, dancing. Checkout the roller video to see why.

We also tested the shooter, which was dead on for accuracy and could pretty much shoot as fast as we could feed. Here is a video of the shooter for your viewing pleasure. The limiting factor is definitely going to be the rate at which we can feed balls into our shooting and rolling mechanisms without jamming. I think we are going to have a tradeoff between having a jam-proof hopper design and capacity.

After the meeting, we hauled the robot to my place for temporary storage until this Sunday’s meeting. I hope we can get some serious work done on Sunday before settling in to watch the Seahawks trounce their opponents in the Superbowl :)

While at my house, Ryan and I played around with a whole bunch of wonderful LEDs, which were recently donated to the club by Lumileds for use on the ROV project. They included twenty 3 watt star emitters, two boards with eighteen emitters each and two rings with 12 emitters each. We drove them using a nice current limiting power supply. Unfortunately, the supply only goes up to about 17.5 volts at max and the ring and boards don’t reach their peak luminosity until about 21 volts. Still the ammount of light put out by these is dazzling. Larry said to me “you can blind em with science or you can blind em with bs.” These LEDs definitely blinded us with science. These are the real deal folks. They are still expensive enough that they haven’t achieved real market penetration yet, but when they do I think they are going to have tons of applications.

Pictures of the LED fun and build meeting can be found here.

Posted in General, ROV Project, Titan Robotics Club | No Comments »

SWN Hacknight – 020106

Posted by Deliverator on 1st February 2006

Eric Butler and I showed up to Hacknight a bit early and were waiting close to an hour before anyone showed up. Hacknight has been canceled at the last minute a number of times in the past, but this usually results in a flurry of emails to the listserv. Between the two of us, we found Casey’s phone number and found out the story.

Turns out the new tower node, Node Atoys had gone down for some unknown reason. Matt, Rob and Casey did troubleshooting for most of the day, swapping radios, settings and testing various theories. In the end, a spectrum analyzer hooked into a directional antenna revealed a high power source of interference coming from the tower. It looks like it may have been a harmonic from some TV gear on the tower. The main transmitter on the tower outputs something like 16KW. That is huge when compared to the 400 mw output by Node Atoy’s Senao card. With the right antennas, sensitive receivers and favorable atmospheric conditions, Hams have been going hundreds or even thousands of miles on similar power. There is even a subculture devoted to the art of long distance RF communications on ultra low power, known as QRP. Of course, some people take different approaches.

Rob had a print copy of his new book, Wireless Networking in the Developing World. The earlier problems with Lulu’s interpretation of the PDF format have been corrected, so get your copies now! The book comes just in time for Rob’s trek to Trieste, Italy for a conference at which he has presented the last couple of years. It looks like he will be gone for about a month. Trieste sounds like a fun place to kill some time. Rob loves good coffee and his favorite brand is grown there. Last weekend at the ROV conference, I saw the submarine Trieste that went some 35,798 feet deep in the Atlantic and came back to tell the tale. By contrast, most military submarines can go something like 800-1000 feet deep, I believe. Don Walsh, one of the two men to make the record setting dive is going to be speaking at the Naval Undersea Maritime Museum in Keyport in a few weeks.

Eric and I are going to grab a 24 db parabolic dish from Casey and do some site surveys from the Eastside to see if we can connect to the tower. If anyone has a house that can see the towers on Capitol Hill and would like their home/biz to be a node on the Network, put yourself on the node map. We are happy to drop on by and see what we can see.

Posted in Mobile Blogging, SWN Hacknight, Tech Stuff, Wireless | No Comments »

FRC Build Meeting – 013106

Posted by Deliverator on 1st February 2006

Today’s build meeting went well. I stopped by school around three and drove a carload of kid’s to Larry’s. I think all told we had 9 students and 3 adults in attendance. Larry’s garage is good for 5 or 6. There were really more hands than strictly necessary, but it is nice that more people are wanting to pitch in and get there hands dirty this year.

The new pulley for the shooter motor got installed and Kevin made some improvements to the motor mount. The improved ball guide (now with countersunk screw holes) for the shooter is now in place. A shield to prevent jamming due to balls bouncing into the top of the shooter appature was created and seems to be effective. If a ball jammed, the motor could overload and blow a breaker, so it was a subtle but important redesign. With these changes, the ball shooter mechanism is more or less finished and seems to be working well in terms of accuracy. We will have to play around to see what sort of refire rate we can achieve.

Larry Coding

Larry mucked around with the code and got the encoders working properly, and set up joystick control for the shooting mechanism. We should be able to start doing some driver training with the robot on non-build days.

Items of immediate concern for the robot:

  • Figure out a dual-purpose ball feeding mechanism to feed balls in the hopper to shooter or front roller.
  • Build up the rest of hopper
  • Build front roller
  • Wheel shields and armor (how much plastic do we need?)
  • Get a partial field set up somewhere (don’t ask me where) so we can start doing driver training & autonomous programming with real distances/field props.

Longer term (uh…only three weeks to go guys!)

  • Play around with ultrasonic emitters and write the “ramming speed” autonomous program
  • Build a formal operator interface housing
  • Try to do some scrimmage matches with other local teams.
  • Pre-ship event
  • Ship the darn thing

Time is being a real sneak this year. I am running around with a constant anxiety attack. 3 weeks to go. 3 weeks to go. 3 weeks to go. Eeeeek!

Robot in Progress

More pictures of today’s build meeting up here

Video of the ball shooter in action, requires the xvid codec for playback.

Posted in General, Tech Stuff, Titan Robotics Club | No Comments »