The Deliverator – Wannabee

So open minded, my thoughts fell out…

Archive for February, 2008

2008 FIRST Portland Regional – Day 2

Posted by Deliverator on 29th February 2008

Most of the remaining TRC members trickled into Portland late last night and after a scant few hours of sleep everyone made an early start today. Day 2 began for me with a trip to Kinco’s with Erik Thulin so that he could print out some glossy color brochures that are being handed out as part of the TRC’s Entrepreneurship Award submission.

The TRC won its first qualifying match of the day with a score of 36 to 32. Several rules are being rigidly enforced, especially with regards to contact outside the bumper zones and movement across quarter field boundaries. Most matches are being lost due to penalties rather than being won due to points. The drive team is being very careful to try and avoid these penalties and they are speaking with alliance partners prior to the matches to try and ensure clean play. I have a feeling that the official seed rankings won’t be a very good indication of team quality this year due to the distorting effects of penalties accrued by partners, so independent scouting is going to be very important this year.

We have a large contingent of TRC members sitting in the bleachers running Stamp Scouting, which is a jointly developed, PHP based statistical scouting application. Each Stamp scout is automatically assigned a robot to watch during a given match and they input various metrics on how their respective robot performed. Over the course of the qualifying matches, Stamp outputs rigorous statistical evidence on how each team performed, as well as anecdotal notes giving us a better idea of who might make desirable alliance partners for the playoff matches.

I’ve uploaded some more pictures from yesterday’s set. More updates to come…

Update 1 – Memnosyne won its second qualifying match 26-0 and is on deck for match 3.

Update 2 – Memnosyne won its third qualifying match 48-12 and we are now off for lunch.

Update 3 – Robot’s eye view videos of two of our matches are now available here and here.

Update 4 – Memnosyne won its fourth qualifying match 42 to 32. Memnosyne managed to autonomously knock down one ball and cross two field markers for a big bonus, which combined with a penalty against the other alliance resulted in the win. I now have four more videos (including front and backwards facing videos of match 4) waiting for sufficient bandwidth to upload.

Update 5 – Memnosyne won its fifth and final match of the day 58 to 6! The TRC is thus far undefeated in competition with two qualifying matches left to play tomorrow! Video to come, but right now everyone wants to celebrate!

Update 6 – All the videos for today have been uploaded. There are four matches featured, with two videos for each match. One video is from a camera mounted on our flag holder, facing forward. The other video angle is facing straight backwards. Rather than link to each individually, click this link for the first video. In the screen that pops up, there will be an area to the right which displays a list of the other videos.

Update 7 – Turns out that one of the matches we played doesn’t count towards our rank. Apparently, they randomly select a team every once in a while to play as a filler bot. The results neither counts towards or against your overall rank and the official scoreboard doesn’t even note that you played an extra match, much less whether you won or lost. The apparent rationale for this system is that they have 55 teams this year and they need to have each of them have the same number of qualifying matches. The magic number of qualifying matches per team this year is 7. This was frustrating to a number of people, as even though the match doesn’t count for anything, the filler bot risks damage which could impact it in matches which do count. Also, many teams look at the rankings this evening to determine potential partners and we are ranked lower with our officially 4 and 0 record (6th of 55) even though we have played and performed well in as many matches as the teams which have officially played in 5 matches. Imo, the way to reconcile the needs of FIRST and the integrity/validity of the rankings is to ensure that all teams have played the same number of matches at the end of Friday and push any filler matches to Saturday. This might result in a few more qualifying matches being played on Saturday, but it seems a more equitable solution in my opinion. It is too late to do anything about it this year, but I plan on writing a letter to the organizing committee for next year’s tournament. The end impact to us is that we have 3 more matches to play tomorrow and a much greater chance of being knocked out of one of the top 8 “picking” seed positions.

I didn’t take nearly as many pictures today, as I was splitting time between working with the on robot video camera system and the stands and didn’t have a long and fast enough telephoto lens to really take interesting match photos. Still, what I did take today will be going into the gallery as fast as my cell phone’s EDGE connection permits.

Posted in Titan Robotics Club | No Comments »

2008 FIRST Portland Regional – Day 1

Posted by Deliverator on 28th February 2008

Been a busy day here at the Rose Arena. Some team members were at the arena by 7:45 this morning for the deboxing of the robot and are still here tweaking code, tightening bolts and tucking away loose cables. After a couple false starts during practice matches this morning, the drive, build and coding teams seem to have gotten a handle on things and have deemed the robot competition ready. As such, I am dropping my own private codename for the bot (Tulip…don’t ask) and have started mentally referring to it by its recently christened name, Mnemosyne  (aka this robot comes from our memories of what we have done well and not so well). Qualifying matches start tomorrow with the playoffs and championship matches on Saturday. The TRC faces some very stiff competition this year. Team 378 from Hawaii and Team 360 in particular have constructed some very high scoring bots. I don’t think Memnosyne is directly competitive with their’s, but barring mechanical failure I think we have a pretty good chance of getting into a competitive alliance for the playoffs.

Internet access is still a bit of an iffy proposition here, but I have managed to upload some pictures of today’s events.

Posted in Titan Robotics Club | No Comments »

Greetings from floor 12

Posted by Deliverator on 27th February 2008

Today I drove to Portland with TRC members in preparation for the First Robotics PNW regional which starts tomorrow and runs through Saturday. This year, due to a convergence of various conferences on the Portland area, we ended up having to stay at a different hotel, DoubleTree Portland – Lloyd Center. The Internet situation is somewhat less than ideal here. The DoubleTree offers free wifi, but only in the lobby. They have data jacks in the rooms, but they are decidedly non-free. A LOT of TRC members wanted to get online from their rooms, so Paul, Jonathan and I whipped up a combination of strategically placed access points, bridges and various oddments to share out my N95’s EDGE connection to everyone. It isn’t fast by any means, but it seems to be holding together and is giving everyone a chance to check their email, download various FIRST game manuals and last minute addenda.

Posted in Titan Robotics Club, Wireless | No Comments »

Updated Picture Galleries

Posted by Deliverator on 23rd February 2008

I just got back from a much needed mini-vacation to Palm Springs, CA following a very hectic TRC build season. Palm Springs itself was pretty boring, although the warm weather there was nice after a damp, cold winter. The areas around Palm Springs however have a lot to offer. I particularly liked Joshua Tree National Park, Palm Springs Aerial Tramway to Mount San Jacinto, Salton Sea and the extensive windmill farms to the northwest of Palm Springs. I did a lot of photography on the trip and afterwards took the time to sort through a bunch of quasi recent dumps from my camera and do some culling. For your viewing pleasure I have the following new/updated galleries:

I also took the time to stitch together some panoramas using PTGui and have uploaded low resolution copies to my Panorama Gallery. This coming week I will be traveling with the TRC to Portland for the FRC regional and will likely return with lots more pictures which will go unsorted for months…

Posted in General, Photography | No Comments »

Apparently someone does make a decent consumer Gigabit Switch: Linksys EG008W

Posted by Deliverator on 3rd February 2008

On Ryan’s recommendation I purchased a Linksys EG008W Gigabit Switch for $99 at Fry’s to replace the craptacular Netgear GS108. The EG008W features 8 auto sensing 10/100/1000 ports and unlike the ports on the GS108 the Linksys properly detected the Gigabit capabilities of all 4 Gigabit NICs I connected to it. The ports are on the back, with indicator lights on the front, which I like. A minor criticism, but the ports on the back are numbered 8-1 vs 1-8 on the front LEDs. The power adapter is slim and was able to be plugged into a power strip with plugs on either side, which was not possible with the GS108. Ryan recalled that his EG008W had a relatively loud fan, which he ended up disabling. My unit appears to be completely passively cooled. Either that or the fan is awfully quiet. The EG008W has worked flawlessly with every NIC I have tested and does not appear to degrade performance when you have a mix of 100 and 1000 mbit devices connected.

I measured the data throughput performance between my fileserver and media center box, which both use on motherboard Gigabit controllers from different manufacturers. To measure the performance, I used a windows port of the popular *nix tool Iperf called Jperf. As you might have guessed from the name, Jperf includes a java based GUI front end to Iperf, making adjustments to various networking and testing parameters easy. Jperf also has the ability to graph results. I played around with a variety of TCP parameters to see if I could get better performance and also tried turning on the Jumbo frames support on both NICs. Unfortunately, the size of Jumbo frames is not standardized, although 9000 bytes seems to be the size most manufacturers support. One of my NICs does not allow one to manually specify the size in the driver and only allowed me to chose from a short list of preset values, none of which is 9000 bytes. So, in the end, no Jumbo frames for me. Even with the default TCP parameters, I was able to achieve 38.2 MB/s throughput, which is not to shabby. That is over 300 mbit of real world speed, more than enough to stream high def video around my network. If you are looking for a broadly compatible, reasonably inexpensive Gigabit switch that performs well under pressure, then you could do much worse than the Linksys EG008W.

Posted in Rants and Raves, Tech Stuff | No Comments »

Does anyone make a decent, 8 port, unmanaged gigabit switch? Aka Netgear GS108 sucks…

Posted by Deliverator on 2nd February 2008

Due to recent construction at my home, I’ve had the opportunity to wire up several areas of the house with Ethernet in a non-ghetto fashion. Up until now I’ve had to make due with a combination of wireless links and Ethernet cabling strung around baseboards and moulding and the like.  I’ve been particularly irked at the paucity of bandwidth to my home theater PC(which has also undergone significant recent improvements of which I will write in a separate entry) and associated multimedia equipment. With the walls open, I went on a shopping spree at Vetco and picked up close to a thousand feet  of cabling split between Cat 6, S-Video, Component, HDMI, RG-6 Coax and 8 gauge speaker wire, as well as associated jack plates, panel boxes and the like.  After close to a week of evening wiring marathons, all the cabling is in place and tested. I will have to pull off the cover plates temporarily when the drywall goes in, but the wiring is now electrically complete. I headed down to Fry’s to pick up a Gigabit switch and ended up picking up a Netgear GS108. After bringing it home and plugging everything in, I quickly ran into problems. One of my Gbit links would not light up and the other was not auto sensing at Gbit speeds and was falling back to 100mbit. I re-tested all my wiring and found no problems. I upgraded my NIC drivers to no avail. I tested both computers plugged directly into the switch via pre-made 3 foot Cat 6 patch cables, which further confirmed that my wiring was not the culprit. I tested each device plugged into other ports just in case a particular port on the switch was bad, also to no avail. I was able to get the NIC which would initially not link at all to work by manually setting it to associate at 100 mbit in the driver, but was unable to get either NIC to work at GB speeds. Two other Gbit Nics auto-sensed Gbit and linked properly on the first time. A couple hours of testing against every ethernet port carrying device I own (which is a lot) revealed one more device (a laptop with onboard 10/100) which would not link  at all (but which worked fine plugged directly into my router and into several 10/100 switches). All in all, exceedingly bad compatibility in a class of device that in my experience tends to work so reliably that you forget it is there.

Thankfully, the computers which are most important to me had Gbit NICs that worked with the Netgear switch (one only because it has two Gbit NICs onboard) so I didn’t feel immediately compelled to waste any more of my time in returning the switch to the store. After a week of use, I wish I had returned it. I’ve experienced periodic loss of connectivity (though the connection lights on the switch stay solid and the NIC still thinks it is working) on multiple boxes, usually in the middle of large file transfers or intensive packet activity. Disabling and re-enabling the NIC or replugging the cable “solves” the problem, but that behavior is simply unacceptable in a device that should be rock solid reliable over a span of years.  After some quick googling, it appears that quite a few other people are having identical problems with the Netgear GS108 and that warranty replacement by Netgear has not solved these issues. My own advice would be to avoid it like the plague.

So, my question to you dear Interwebs is this: Does anyone make a decent 8 port Gbit switch?

My requirements:

-Would ideally have indicator lights one front panel which indicate connection status, speed and activity for each port and has the actual ports located on the back.

-Broad compatibility at Gbit speeds with a wide range of Gbit PHYs specifically ones from Marvel, Realtek and Nvidia. If not compatible, should gracefully fail down to 100mbit.

-Mixing 100mbit and Gbit devices on the switch should not cause the switch to degrade all traffic to the slowest common speed (I’ve read that several are known to do this). i.e. Gbit devices should be able to talk to other Gbit devices at Gbit speeds, even in the presence of 100 mbit devices.

-Should support Jumbo frames for highest possible throughput. I am not just farting around here. One of the uses of this new and improved network is flinging IP HDTV around my house from Beyond TV, so I need every bit of bandwidth I can squeeze out of the network.

-Expense is not the main concern here. Reliability is paramount. I have found people with many nice things to say about any 8 port Gbit switch, so if need be, lets extend all the above requirements to a 16 or 24 port switch. I don’t really need the extra ports, but if I have to move to a enterprise class device to do what I want, so be it. Oh, I don’t really need a managed switch with VLANs and whatnot either…

Posted in Rants and Raves, Tech Stuff | 1 Comment »