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Multi-channel RC servo signal to RS232 converter

Posted by Roberto Hawkowski on August 25, 2009 at 2:24am
Hello All,There are many small, off-the-shelf boards which can accept TTL or RS232 serial data and control/drive multiple RC servo motor. What I am looking for is the reverse of this operations. That is, I want to measure multiple servo pulses with one small unit, and send the measured values via a TTL or RS232 port.

Do you know if there is any small, off-the-shelf solution for this?Roberto
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3D Robotics

Current standings in the T3 contest (just one week to go!)

Posted by Chris Anderson on August 24, 2009 at 9:05am

Here are the latest standings (just top 10) for the T3 contest. Our judge, Gary Mortimer, has added flags to inspire national rivalries and inter-Nordic competition. Paparazzi and AttoPilot are showing the power of mature navigation algorythms and well-turned planes, but we've got a week before the Aug 31st deadline, so perhaps some ace ArduPilot tuners will get their planes dialed in before then (I'm at the beach all week playing with config settings and flying dozens of times a day, so I may be able to improve my own time)
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3D Robotics

NASA Ames UAV field trip! (Sept 2)

Posted by Chris Anderson on August 19, 2009 at 8:00pm
Chad Frost, the manager of the NASA Autonomous Systems and Robotics department, has kindly offered to give a dozen lucky DIY Drones members a tour of the UAV facilities at NASA Ames in Mountain View, CA. This is a totally unique experience (I've done it before for a Wired Science PBS TV episode) and totally worth taking a few hours off work for! The date is Wed, Sept 2nd, and we're shooting for an 10:30 am arrival, staying through lunch. Chad will give us a tour of ~3 UAV projects. You'll make your own way to NASA Ames and park in the visitors' center, and Chad will escort us through security. Due to NASA regulations, this is limited to US citizens and no more than 12 people. Sign up in the comments below. Futher instructions will come closer to the date.
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India seeks micro UAVs

Posted by Wladyslaw Motyka on August 19, 2009 at 2:17am
India seeks micro UAVsBy Vivek RaghuvanshiOctober 26, 2007The Indian Army is on a global hunt to buy unspecified numbers of micro UAVs to fly surveillance missions in the upper reaches of Jammu and Kashmir and for anti-insurgency operations in the country’s northeast.Bids have been sent to companies that make the Bird Eye (Israel Aerospace Industries), FanTail (Singapore Technologies Aerospace), Raven (U.S. firm AeroVironment), Skylark (Israel’s Elbit) and Tracker (Europe’s EADS).A senior Army official said the service will need more than 200 UAVs in the next three to five years, with the requirement increasing as more urban areas are put under surveillance.The micro UAVs are a priority procurement for the Army and could be inducted into service by mid-2008. The Army has specified no numbers in the bid, but service sources said the order could increase depending on the UAV’s performance as funds are available.The global bids, sent early this month, stipulate that the micro UAV selected should be able to:å Perform reconnaissance and surveillance over mountains, day and night, and immediately transmit data to operators by voice and video.å Identify and detect targets.å Do surveillance of rural and urban areas where insurgents operate.å Assess post-strike damages.The micro UAV also must weigh no more than 40 kilograms; be easy to assemble; have a low-noise engine, fixed or rotary wings and a low heat signature; and be able to avoid enemy detection and engagement.The system’s ground control station should be a portable laptop that can display video and flight data on a digital map background and control the UAV in flight. Also, the UAV should be capable of performing a preprogrammed flight when navigation way points are fed into the computer.A crew of two should be able to set up and operate the UAV and perform the launch mission in 15 minutes. It should resist electronic countermeasures.The Army also wants a UAV that can operate in temperatures between minus-10 degrees and 50 degrees Celsius, fly at speeds up to 50 kilometers per hour at a range of at least 10 kilometers, and endure 90 minutes of flight.
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3D Robotics

Poll: When should we have scheduled chat?

Posted by Chris Anderson on August 18, 2009 at 8:00pm
Some of you have noticed that we've added a chat app to this site. The problem is that we're all busy and scattered around the world's time zones, so it's hard to get a critical mass of people in the chat room at any one time. So I suggest a scheduled chat hour, once a week. When? The poll is below, but I'll make my own preference clear first. I'm in California, and the only predictable free time I've got is on Sunday evenings. I'm fine if people want other times, but I may not be able to participate.
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3D Robotics

Surplus missile gyros!

Posted by Chris Anderson on August 18, 2009 at 4:00pm

Probably useless today, but what a cool bit of autopilot nostalgia! A mechanical gyro from a missile for $16.95. From the product listing: "These are precision rate gyros that were made for use in guidance systems of military missiles. The last time we had these we were told that they were from the Maverick Missile Program, however, we don't know for sure. They were made in 1981, they are new and were made by Honeywell. The part# is 3051235-1 and the model number is GG440A18. They are 2 1/4" x 15/16" Dia. The body is gold plated and the gyroscope has 6 color coded flexible wire leads. We supply it with a circuit diagram showing how to use a 741 Op Amp, a 2N3904 transistor, a 2N3906 transistor, and a few resistors and capacitors, to cause the internal gyro motor to spin from a 400Hz signal that the circuit produces (the circuit requires + and - 15VDC). The circuit shows which leads of the gyro to use to spin it, however we don't have any other data. We were told that the phase angle output changes as the gyro is tilted, This gyro was known as the Golden Gnat and we were told it was used in autopilots, missile guidance and robotics. Hurry these will sell quickly!" (via BlueSky on RCGroups) Update: more on the history of this gyro:

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3D Robotics

Current standings in the T3 contest

Posted by Chris Anderson on August 18, 2009 at 8:11am

With just two weekend still to go in the T3 Contest, here are the latest standings. Paparazzi is in the lead, but we have practically every other hobby-grade autopilot represented, including ArduPilot, AttoPilot, PicoPilot, FlexiPilot, and even the rarely-seen CropCam's MP 2028. The 60 second mark has been broken, and one clever entrant (Krzysztof Bosak) has even used music from the band T3 in his video to win extra points from the judge/contest co-creator (Gary Mortimer). Just a reminder that everyone (any autopilot/aircraft) is free to enter but please read the rules about the evidence you have to submit (track on a map, KML file and video). Also, anybody can enter as many times as they want, so if you weren't happy with your first run, try, try again! The final day for entries in Aug 31s, and winners will be announce on Sept 1. The next contest will also be announced on that day.
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The "Bravo" Flying Wing has flown

Posted by Stephen Carlson on August 18, 2009 at 12:56am
It flies! Earlier today, I stepped outside, walked 80 feet to the 10+ acre field next to my house, and chucked my brand new flying wing. There are few things in the world like flying a plane that you've scratch built. And unlike many of my plane projects in years past, this one actually flew well.I've been working on UAV platforms all summer. Although I can't show my regular research project (If I told ya I'd have to, ah..... NDA ya!), I can show this aircraft, which is being built for the research project and as a typical flying wing UAV platform.

I modeled the entire thing down to the details on Autodesk Inventor 2010. (Well, not every detail, but most.)

If I can get my Ardupilot working well enough, I might tempt a shot at the T3 Contest with this thing.
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T3

T3 speed contest: abusing smooth-flying EasyStar.

Posted by Krzysztof Bosak on August 17, 2009 at 3:46pm

T3 Trust Time Trial robotic airplane pattern flying using FLEXIPILOT from Krzysztof Bosak on Vimeo.

The overall time is disappointing but was expected.I used unprepared airframe, just trottled up settings,it is a surprise it flew the pattern without too much oscillations(it has gain scheduling related to throttle, what saved the day).Altitude hold is below average at 10m.Time: 1:26.The platform is dull gray development EasyStar workhorse rudder-only, too ugly to show.Onboard 2 GPS and 3 autopilots: one FLEXIPILOT piloting and logging, one FLEXIPILOT just logging,one RVOSD (not used except for display).
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New Laser Rangefinder

Posted by Sarel P. Wagner on August 17, 2009 at 8:26am
Aerius Photonics of Ventura, Calif., is showing its new 25-gram miniature laser rangefinder, the MLR 100, designed for use as a proximity sensor, height above ground sensor, laser altimeter and scanning transceiver for miniature laser detection and ranging (LADAR) systems.

Also a link: http://www.procerusuav.com/Downloads/DataSheets/AeriusMiniatureLaserRangefinder.pdfRgrds
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3D Robotics

Testing Atto and Ardu at the field--success and near disaster

Posted by Chris Anderson on August 16, 2009 at 8:57pm
I've got twin EasyStars, one with AttoPilot and one with ArduPilot. I had them both out today to begin the process of benchmarking the two autopilots against each other. Two interesting things happened, one scary, the other exhilerating: 1) It's quite windy at our field these days and I've been having trouble with the the current ArduPilot navigation algorithms, so I set out to try various PID settings. I put the EZ in autonomous mode and just started watching it hunt for waypoints, usually ineffectually, while keeping an eye on the ArduStation to diagnose the problem. I kept the plane at a pretty high altitude, and after looking at the screen a bit too long I looked up for the plane and it was gone! I could still hear the motor, but it was nowhere in sight. I switched it into RTL mode and scanned the skies. Nothing! And the motor got fainter and fainter. Argh! Panicked, I booted up the laptop, switched the Xbee to the Sparkfun adapter and plugged it in, opening up a EVDO wireless Internet connection and loading the ArduStation software to see if I could find the plane on the moving map. At this point, the plane had been gone for at least ten minutes, and I was sure it had gone out to sea or to another county, but when I called up the moving map, I was delighted to see that it was still in the air, still moving and apparently right overhead! My eight-year-old son started scanning the sky right overhead and with his great eyes he saw it, at a tremendous altitude. Eventually I could see it, too, and I switched to manual, cut the throttle and put it in a dive. A minute later it was landing right in front of us. Whew! I'm not sure why altitude hold didn't work, but RTL sure did. If we hadn't had the wireless telemetry, I would have assumed the plane was gone and driven off. Many minutes later, it would have gently returned to earth right where we'd been standing. Yay Xbee! BTW, while replaying the video from the flight, I could hear that the RC system was losing its signal really often, with the ESC rebooting and all sorts of scary stuff. I could also hear the 1Hz buzz of interference from the Xbee module. I'm wondering if the Xbee or RF noise from ArduPilot is messing up my RC system. More testing required... 2) I also tested AttoPilot in the other EasyStar. Yesterday's trials had shown that the default gains were way to high for the EZ, so I'd brought them down from the default 10 to 7. Putting it in the air, it was clear that was too high, too, so I brought them down to 5. That turned out to be perfect, and I let it fly circles overhead. It was eye-opening. Dean has written navigation algorithms that put ours to shame, The EZ didn't just sorta-circle or do random figure eights overhead, it sped around in perfect 100m radius circles, like a protractor. Wow. We've got a lot of work to do to equal that. Next weekend I'm going to have it do the T3 contest, and I think you'll be impressed. BTW, here's the rest of the UAV fleet that I'll be benchmarking over the next month or two: 1) EasyStar with ArduPilot 2.3 (EM406) 2) Superstar with ArduPilot 2.3 (uBlox 5) 3) EasyStar with AttoPilot 1.8 4) EasyGlider with ArduPilot 2.3 (uBlox 5) 5) Funjet with Paparazzi Tiny 2.1 6) Superstar with UAV DevBoard 2 I've retired the old PicoPilots and my first gen Lego Mindstorms autopilots. I'm also sticking to park flier aircraft, so nothing that I can't hand launch and land in grass for now (that means no Predators or big trainers) I've
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3D Robotics

Our 5,000th member!

Posted by Chris Anderson on August 15, 2009 at 8:30pm

Congrats to Pablo Ruiz of Spain, who is our 5,000th member! In the two years that this site has been running, it has grown to nearly 5,000 visitors a day and nearly 15,000 daily page views (see Google Analytics chart above). Over that time it has had a total of more than a million visitors and 4.2 million page views. Nearly 1,000 ArduPilots have been sold along with more than 100 UAV DevBoards. And it feels like we've only just got going!
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