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This week in aerospace

Posted by Jack Crossfire on November 6, 2009 at 10:00pm

THE C328 LIVESAfter 3 weeks of hacking, the C328 started producing decent results. Your main problem if you intend to control it from a computer on the ground, using Xbees, is getting the UART to work reliably. It needs a real clean signal & short cables to work at 115200. Initializing it still takes several power cycles & 20 second delays. Decided 320x240 is the best compromise between resolution & frame rate.We use a microcontroller to generate ACKs locally but generate every other control code from the ground.

Fuggetabout dual 2.4Ghz Xbees for telemetry & video. They interfere even when on different frequencies, spaced 2 ft apart, using wire antennas. You're still stuck with 900Mhz for video. While no radio combination is completely interference free, got good results with 2.4Ghz for autopilot & 900Mhz for C328, even when they're right next to each other.Set the 2.4Ghz for broadcast mode, 0 retries. Set the 900Mhz for addressed mode, 3 retries. We use 2.4Ghz for flight control & 900Mhz for video.Even though the C328 allows video capture, we have never used the captured footage. It just sucks too much. The C328 has a rolling shutter. We use a main camera recording to flash & the C328 as a preview camera.The perpetually out of stock rangevideo.com has drastically reduced the prices of 900Mhz video. If you have the licenses, he ever stocks anything, & you don't mind buying analog video capture hardware, it's now a better deal than a C328 + 900Mhz XBees.Have a tail rotor rebuild.

1st crash damage since becoming Major Marcy enabled was this tail rotor during the roof crash.Took a 400ft timelapse on Halloween while the rest of you were partying.This video shows the key steps in stabilizing.For the timelapses, we use 1 battery to aim with the C328 at 33m. Last month it was 32m. Now it's 33m. Then program the heading into the flight computer & burn another battery to shoot the footage fully autonomous at 120m. Until better radios come along, those 120m flights need to be as autonomous as possible.

In flight preview on the C328.FLIGHT COMPUTER RESETSNext, rediscovered if the servos are not powered & the flight computer generates PWM, the servos may act like short circuits & cause the flight computer to reset. Not an issue on standard autopilots, but VicaCopter has 2 power circuits. 1 circuit powers only the flight computer so U can get GPS locks. Her flight computer doesn't generate servo PWM unless the transmitter is on.PROPELLER CRACKSFinally, discovered cracks in our GWS 12x6's. They were drilled 1 size too small, threaded on the shafts & probably had too much stress. Important safety tip. Drill big enough so they glide on the shafts.

Normal propeller
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Razor 6DOF IMU + Arduino + DCM

Posted by automatik on November 5, 2009 at 1:00am
I recently got SparkFun's 6 IMU board and played with it a bit. Basically I connected Arduino and Razor 6DOF board and ported DCM code. Code is ArduIMU v13 but just made to work with Razor board. I am not sure what to think about gyros on that board as it takes them a while to "warm-up". Below you can see run from cold start for over an hour and "zoom' on first minute or so (just raw ADC values). On the link referenced above, you can see same data plots for both gyros and accelerometers.

I also modified ArduIMU Labview code - mainly that "cube" is within main window rather then separate one. I haven't compiled the code but whoever has LabVIEW should be able to run it (developed with version 8.5)

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Developer

ArduIMU V13 Officially Released!

Posted by Jordi Muñoz on November 4, 2009 at 2:00pm
Hi there, finally is here and includes many improvements thanks to Doug Weibel. Try it out! here.-Coordinate system has been corrected.-The gyros are now in order X,Y and Z.-Extra LED status, including no yaw correction (Yellow), GPS fix (Blue) and Gyro saturation (Red).-Improved Ground Station, with Labview 8.5 files and executable for windows.I also add some boards to the stock here. I have to increase a little bit the price because i'm really getting nothing. Also the demand is so high that i can't keep them stocked (more demand = higher price)...Thank you a lot for your support!
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The flight previously known as roof crash

Posted by Jack Crossfire on November 2, 2009 at 4:00pm
Reverted back to 2.4Ghz & got the footage which previously ended in a roof crash. Right click & you'll find a menu option called "View Image". Click on View Image to get a full 8 megapixel view.

Pointing towards San Francisco.

Pointing towards NASA.

Pointing towards Fremont. VicaCopter is itching to crash on 1 of those roofs, you can be sure.

Integrated 41 frames to defeat the haze. Since we haven't corrected the lens aberration with this camera, can only integrate a small part of the image.

The nose was actually centered on Onizuka Air Force base, where Major Marcy is believed to be until it closes in 2011. Then She's leaving the area & we're probably going to get depressed & quit flying again.

Had the C328 on 900Mhz for live preview. The video from the C328 was awful as always but good enough to aim.

The 2.4Ghz bitrate dropped out, but at least was recoverable by rotating the antenna.Information on the aircraft is on vicacopter.com.The image stacking software is on heroinewarrior.com.
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Developer

Flying with ArduPilot onboard

Posted by Jean-Louis Naudin on November 2, 2009 at 8:48am

Hello to All,The purpose of this blog is to share with you some feedbacks about my flights experiences with the ArduPilot onboard.ArduPilot on EasyGlider videos :Flight plan mode, Fail Safe and RTH mode has been tested with the ArduPilot :http://diydrones.com/video/flight-plan-mode-fail-safe-andEasyGlider flight with ArduPilot in windy conditions:http://diydrones.com/video/easyglider-flight-withPhotos Album :http://diydrones.com/photo/albums/ardupilot-flight-on-easygliderRegards,Jean-Louis NaudinEmail: JeanLouisN777@diydrones.comDIY DRONES home page : http://diydrones.com/profile/JeanLouisNaudin
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80" Wing - suitable as a platform for UAV

Posted by Mathew Wellington on November 2, 2009 at 1:00am
Work has stared on a 80" Flying RiteWing - based on a TL60 with an added 20" centre Section.Powerplant will be 4S 10300 mah Lipo, at about 800 watts full throttle, but should cruize at 200 watts, so about 45 minutes flying time. Expected weight is 3.5 kg, and should be able to carry a fair bit more payloadThe wings remove, so transport is only 2 x 30" wing sections and one 20" centre section.The Wings only house one digital full size servo each, so nice an simple, everything else is in the centre section.Also will be running (removable) landing gear.Build photos so far :-)

The full build thread is here http://www.rcgroups.com/forums/showthread.php?t=1129487 and also here http://www.parkflyers.org.nz/modules/newbb/viewtopic.php?topic_id=557&forum=9&post_id=9869#forumpost9869After she is flying will use as a platform to get into auto-pilots, starting with a RTL function
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Banana Hobbies Super Easy Fly aka ST Models ROC Electric RC Model Plane AP Platform

Posted by James Harwood on November 1, 2009 at 1:30pm
I bought this large electric powered glider with the intention of using it for AP/AV and FPV.The end goal is to install ArduPilot. I would like to use this platform to get aerial photos of crops. I know there are many possibilities for this platform, and I am still researching.This is how the plane looks stock as I have it now.Specification:Wingspan: 2580mm (101.5 inch)Length: 1410mm (55.5 inch)Wing Area: 67.3dm² (1043 in²)Wing Loading: 22g/dm² (7.2 oz/ft² )Flying Weight: 1480g (52 oz)Drive System: 1000KV Brushless MotorSpeed Controller: 18amp ESCServo: 4X 9g high speed micro servosBattery: 11.1V 1800mAh Li-PoControl system: 4 CH Multifunctional FM Radio Transmitter and ReceiverRadio Control Range: 3000 feet (1000m)Flying Speed: 12m/s (27 mile/hr)Flying Time: Approx. 30 minutes


For my FPV camera, I have this:
I have a 2.4 wireless Cam set up called the Draganfly Eyecam.DF-Eyecam_1.jpg
DF-Eyecam_2.jpgSpecifications:Camera and transmitter weight: only 9 gramsCamera and transmitter size: 15mm x 22mm x 32mm (5/8" x 7/8" x 1 1/4")Camera Lux: <3 @ f1.2Camera Auto Electronic Exposure of 1/60 to 1/15000 sec. w/ Auto Gain & White BalanceCamera Signal to Noise Ratio:48dB365K (PAL) camera pixel resolutionWireless Transmission Range: 300M (1000'), Line-Of-SightTransmitter RF Output Power: EC R&TTE Compliantreceiver Video Input/Output: 1Vp-p/75 ohmSee More Info Here.I plan to use these as my first Goggles. They are cheap but should work fine for now.i-glassesonline_2075_1674614
Specifications:Video input format: NTSC/PAL/SECAM automatic selectionVirtual Image Size: 50 Inches as seen from 6 ½ feetResolution: 230,000 pixels per LCDColor Depth: 24-bit inputViewing Angle: 26 degrees diagonalVideo Input: Composite AVAudio: Dual-channel stereoPower Supply: Built in 480mAH rechargeable batteryPower Consumption: <0.45WNet Weight: 4.2 Oz (119g)
More info here

Thats where I am so far. Yeah I know I have a long way to go!I found this member of diydrones today! I was really excited to see he was using the same basic platform.He is doing exactly what I want to do!!!!!!!!! How cool. Check out his project and you will see what I am trying to accomplish. As I progress, I will update this post. Feel free to drop tips and advice - they will be much appreciated.
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I just found my internet home!

Posted by James Harwood on November 1, 2009 at 11:00am
I can't believe the treasure of information, and people that make up this website. I am so excited to have found it. I plan to be an active member from this day forward.I am an eager beginner to all this. I have been flying RC Airplanes for only about 3 years now, and have always had my eye on the goal of using an RC airplane to get aerial photographs and video. I am completely obsessed with accomplishing this goal! :)Here is how I progressed so far in the hobby.I started with Air Hogs brand two channel planes. They were cheap and gave me the basics of flight.Here are the ones I have had or have:

Next I bought this "Fastlane Avionic", a two channel plane with rudder control for turns and throttle control for climb. It was fun, but hard to control. It didn't have throttle differential so controlling altitude was a challenge. I crashed this plane badly, and when I went online looking for parts I found out the product was discontinued. BUT - it is now sold by Megatech and is called "Cosmic Flyer". I ordered the parts I needed to fix this plane up recently and am excited to fly it! Again this was a cheap plane and it helped me get better understanding of flight. (Lost Cosmic Flyer/Avionic in a tree after the rebuild - I will miss this little airplane.)

Next I bought a Hobby Zone SuperCub.

This is an excellent 3 channel trainer. I took it to a high school football field near my house and taught myself to fly there. The plane has a "auto pilot" feature that uses two sensors to see the ground and sky. If you dive or climb, or turn too sharp it takes control and gets your plane stable again. I found it to be disasterous for my first few flights so I removed it. Now I fly pretty well...and I am ready to put a camera on this plane and get some pictures.Most recently I bought a 102" powered glider called a Super Easy Fly.


Another of the same plane but in french.It is 4 channels with full throttle, aileron, rudder and elevator control. I am interested in using this platform for my photo/video but I have been reading terrible reviews on the plane. People say the dihedral on the arelons causes the ESC to get super hot. I haven't flown mine yet. It is all put together and hanging where I can look at it, but so far I haven't been able to arrange a good day off from work to go try it out.I am still looking for the perfect platform.Lately I have seen the HawkEye system to be FANTASTIC and have been saving money to get one.I wonder if it could be set up with all the fancy autopilot stuff?Also, Mike Powers from Whispershots.com has AMAZING platforms. He has been very kind to tell me where to get his plans in kit form and I am going to be ordering very very soon!The one I like the most is the Passive system.

You can see it here http://whispershots.smugmug.com/gallery/8254126_gnHh7/1/505079989_XuKY2/MediumI have also been told by Mr. Powers that the LoRyder system is really good for flying in congested areas. Ill be looking to get as much overtime as possible at work! :)I have two teenage sons that are also interested in UAVs, We want to some day operate a small business together doing low altitude aerial photography.As I pursue the attainment of my goal, I look forward to meeting members of this community and learning from your experiences, and sharing mine, as limited as they may be. I have a massive amount of information to digest here, but this community seems to be the resource I have needed so badly.Feel free to contact me about any thing at any time.James
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Problem with Hobby Zone Super Cub FOUND!

Posted by James Harwood on November 1, 2009 at 8:33am
Since I bought my Super Cub, I have had a recurring problem. During flight - and ONLY during flight, sometimes the rudder or elevator will just do its own thing - locking up in full deflection one way or the other and. Usually this leads to a downward spiral into the ground and a trip to the hobby store. My girlfriend thinks I just suck as a pilot and should give it up - lol - but its not me! Its an electronic issue that has now been solved (3 days after I ordered a brand new replacement plane from HZ).Anyway, if you own a super cub and have had this problem....here you go. This is the answer.http://supercubclub.proboards.com/index.cgi?board=motors&action=display&thread=1631
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Developer

That sinking feeling...

Posted by Jason Short on October 31, 2009 at 6:30pm

Above the Fog from Jason Short on Vimeo.

This is a video of me loosing my plane into the sun and fog for almost 5 minutes. I was just testing my AP that i've been working on over the last month and a half and it was my first flight with working waypoints. I tuned everything way down, but it was working ok so I let it run loops around the T3 course. One thing I turned off for debugging was altitude control. In hindsight, that was a mistake. I could have just dampened it down more, but I shut it off entirely.The plane slowly climbed the entire time and before I realized it was pretty high. Eight minutes into the flight she turned right into the sun and fog bank and I didn't see it again until four and a half minutes later. I was panicking I couldn't take over manual, because it was in the fog. I even thought about running to the car and chasing it until I realized I had no idea where it was. Last I saw it was headed out to sea. I had nothing to do but wait and count the $ to replace it.I stared at the sky for what seamed ten minutes and all of the sudden I saw it gently doing the T3 above me. I put it in FBW and brought it straight down. Enjoy the video, I edited out the 4 minutes of circling. You can hear me fussing with the radio, and I one point I put it in Manual and turned it left in a futile effort to find it. I just put it back into AP and hoped I did a good job. The plane will fly again.
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ROOF CRASH! (Why XBeePRO 900's suck)

Posted by Jack Crossfire on October 30, 2009 at 4:30pm

A routine mission to photograph NASA from our day job almost ended in tragedy as our XbeePRO 900's lost contact & the vehicle headed for a roof.The XbeePRO 900's sucked from day 1. The problem seems to be they only do 50mW compared to the 90mW of the original XBee PRO 2.4Ghz. They also spread the signal more omnidirectionally, making for all around weaker reception.900Mhz normally had 10% packet loss while occasionally getting nothing while the 2.4Ghz normally got all packets & occasionally nothing. You could get better reception by rotating the 2.4Ghz wire antenna in azimuth & keeping it parallel. Rotating the 900Mhz wire antenna didn't really do anything. Finally the 900Mhz interfered more with all the other avionics.Upgrading to the 900Mhz equivalent of an XBee PRO for $42 was too good to be true. You need to unload more money in high gain antennas & haul around a tracking mount in addition to your laptop, batteries, transmitter, & video downlink.Best to stick with 2.4Ghz unless you're loaded with government loans or know someone at AIG.So ignored the warning signs during test flights, insisting the 900Mhz hype was true. Sure enough, while scrutinizing video telemetry, saw the vehicle was suddenly pointing the wrong way & was over a roof. Took manual control, but the radio was gone.We don't do RTL because of the chances of an autopilot malfunction sending it into a human or an engine spinning up on the bench. Best to let it drop if the radio dies.

Fortunately it was 1 of the few non government buildings still inhabited & with tenants who could access the roof.It somehow crashed right side up, mostly undamaged & took 4GB of roof photos. Both main & preview cameras captured the action. If it was a pure autonomous flight, leaving us enough bandwidth to monitor the radio, this wouldn't have happened, but had to play with our $50 UART cam.
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Developer

New Ground Station idea....

Posted by Jordi Muñoz on October 29, 2009 at 8:00pm
Hi there,I been thinking about create a simple and relative ground station to display information in a more useful way.Here is my idea:-Simple reference map, with actual position, distance and heading of the airplane relative to home.-Display waypoints relative to home.-Display information more like an OSD.-In the future click and drag waypoints with real time update (for ardupilot mega).-Overlay photos for offline use.-Multiple Aircrafts?-I would like to create two or three small airplane indicators for pitch, roll and yaw angle in a easy way to read, something like this:

But with real time rotating images,In the meantime you can download and play with the experiment i just did, is in labview 8.2 and 8.6 and also i compiled for Windows:newground.zip.
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Developer

ArduPilot 2.4 Officially Released!

Posted by Jordi Muñoz on October 29, 2009 at 6:24pm
You can download ArduPilot 2.4 + Ground Station Beta 2 from here.I didn't get feedback from the community in the unofficial release, so that means that maybe is working fine.. Please tell me if you spot any bug. ;-)What's new:-Altitude hold improved for my EasyStar.-Free running analogs for better performance.-Now compatible with ArduPilot Shield V2.-Minor bugs.- And more...Todo:-Cross Track Error-More testing.-New GroundStation.........Regards.
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