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Male
About
Location
Los Alamos, NM
Activity Feed
"Hey Chris, Roadrunner took first in the micro category, and Minuteman took second in the peleton, both using the trusty ArduPilot "uno". Not as sexy as it's big brother, but still capable. "
"@Randy: Thanks for posing the video. I think that's the 2nd run, when the wheel broke. "
"@Frank: Thanks for the correction. 200Hz did seem a bit high. I'm guessing they won't penalize barrel tipping...it does come with some risks (for the vehicle), and it provides some Hollywood-style action. I heard they are considering solo runs for…"
"That is a good point. I did some characterization of speed vs tire diameter, and between 0 and 15 mph I got an increase of about 10% in tire diameter (or distance traveled per encoder count). That's significant, but fortunately not a deal-breaker…"
MinutemanThis is another write-up of my Sparkfun AVC experience. This year I worked closely with Roadrunner, who ran a similar vehicle and the same code. We collaborated using google code and SVN, which made us feel like "real"…
I'm working on a return-to-launch high altitude glider (balloon launched). My radio system needs to be able to communicate at 100km or more. My current plan is to use an FRS radio. This radio is modified to work on the 70cm ham band, and should be…
I'm starting a high altitude return-to-sender balloon launched glider project. I want to keep it simple, and I think my first decision is airframe. I'm wondering if it would be feasible to use a small glider like this mini swift for rudder-only…
"Thanks, everyone, for the input. I think for an airplane in an open sky, with good GPS lock and few, if any obstacles, GPS is great. But for a ground vehicle in the sparkfun parking lot, moving 20+ mph, it has some serious limitations. Sparkfun's…"
GPS vs. Dead ReckoningSo, I decided to try the bare minimum first, then add complexity as needed. It turned out that dead-reckoning worked pretty well. With some refinements, I think it will work REALLY well. Also I came to the conclusion that heavy…
"John, thanks for the input. I would argue, though, that my approach was the very essence of the spirit of the competition. Of the bots I surveyed at the competition, I think every one depended on a GPS, and probably a compass or gyro, at the bare…"
"HappyK, thanks for the perspective and the comments. I remember chatting with you, and I remember you saying that you would be at the competition. I didn't put 2 and 2 together until now. I wish I had thought to chat with you about your ground…"
Minuteman in the pits Lining up for the final heat Roadrunner 8:30 AM Friday, April 22. I leave Los Alamos, NM, headed for Denver. The weather is blustery, but I have a good audio book to keep me entertained for the 6 hour drive. After a stop for…
"Hey John, great job on the race. Getting throttle control and waypoint management working in about a day is quite impressive!
Your rustler looked pretty fast. Was it the one that shot out like a rocket at the beginning of the mass start? That was…"
Your rustler looked pretty fast. Was it the one that shot out like a rocket at the beginning of the mass start? That was…"
"Hmm, I have to be pretty accurate with my starting position, but mostly with my starting angle. I don't think GPS would give me the accuracy I need. A good mark on the ground seems to work well. Also my vehicle's navigation system doesn't…"
"There was a thread a while back on low gyro drift obtained by ADC oversampling. I've been using this on my sparkfun AVC project and it works well. I sample a gyro at 9.6 kHz on an ardupilot, using the free-running ADC mode. Works like a champ (and…"
"It looks at a small disk (from an old computer mouse) that is attached to the input shaft of the transmission. It outputs a 0.4V to 4.5V signal, so that it can be read directly by an external interrupt on the ardupilot. That way it just runs in the…"
