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Gyros for ArduPilot

Posted by Simon on January 15, 2009 at 5:53am
Hi,I understand the issues about using simple rate gyros with an autopilot - i.e. you can't unless teamed with accelerometers etc - but could one use a head-lock gyro for stabilisation via aileron control ?Max flight time would be about 10 - 15 mins.Simon
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Blimpduino project underway

Posted by profmason on January 14, 2009 at 7:04pm
I have a winter student doing a blimpduino as a project.So far we have it out of the box and running the default beacon finding code with no problem. I am having the student go through the project as an opportunity to learn about microcontrollers, programming, navigation etc. If you want to follow our progress, you can look at: mtsacflight.blogspot.comThere are flight videos and more.
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3D Robotics

ArduPilot voltage issue turns into Sparkfun tutorial!

Posted by Chris Anderson on January 13, 2009 at 11:14pm
You gotta love the guys at Sparkfun. We had a small compatibility issue with the GPS daughterboard that was caused by the polarity protection diode on ArduPilot that has the effect of dropping the 5v Rx voltage down to 4.3v on ArduPilot. Not a problem for ArduPilot, but could be a problem with voltage-sensitive add-ons. I asked Nathan at Sparkfun for advice. Not only did he solve the problem (the next production run of the boards will have a power regulator), but he wrote a whole tutorial on the issue!
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CropCam UAV for sale (used)

Posted by nebraska arial photos on January 13, 2009 at 3:00pm
We have a cropcam which we are looking to sell. It comes with all hardware and software needed to fly. It also comes with a laptop computer that has a recent update to all Microsoft office software ($670). It also comes with several spare servos, parts and four batteries thunderpower batteries with an astro charger for the batteries. Two optio A20 cameras will be included for an extra $100 but the lens doesn't always open on one and the LCD is broke on the other. We are asking $6500 for the package ($8500 value). The plane has a few minor dings and fixes but is definitely flight ready. It has made only a few flights since it was sent in to cropcam for a repair and test flight. And has maybe 50 flights its hole life.To learn more about the cropcam visit their website at www.cropcam.comCall me at 402 440 2839 or email me with any questions jayme@burkeyfarms.comJayme Dick-BurkeyBurkey Farms Inc.Milford, Nebraska
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3D Robotics

All of Sparkfun's new UAV boards sold out in a week!

Posted by Chris Anderson on January 13, 2009 at 9:22am

Good news, bad news from Sparkfun's big UAV push: ArduPilot and Bill Premerlani's autopilot board both sold out in the first week (I think ArduPilot sold out in it's first ten minutes!), as did Dean Goedde's AttoPilot power sensor. All are available to backorder, and I know at least another 15 ArduPilots have already been filled from backorder, with another production run of about 100 about to start. Bill's board is on the production schedule for restocking and Dean has lots more of his current sensor boards on the way to Sparkfun. I expect all inventory issues will have stabilized within a month. The next round of ArduPilots will have a small tweak on the power regulator that will bring the board voltage closer to 5v (rather than the current 4.3v). This should have no effect on the board itself, but will make it easier to add accessories and other sensor that may be more voltage sensitive than ArduPilot itself.
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3D Robotics

Guardian 2.0-Fast Response UAV

Posted by Julian on January 12, 2009 at 5:00pm

With UAVs coming into more widespread service in the armed services and all around us everyday, its becoming harder and harder to find and fill specialized niches of operation, and thats where the Guardian comes in. Designed for close convoy support, The Guardian was designed for near instantaneous deployment in contrast to the Raven which requires hand launch. The goal is to have it launch out of a canister mounted on the side of a convoy vehicle, so in ambush situations where hand launch of a support aircraft would be deemed impossible, The Guardian could provide a near instantaneous "eye in the sky."Orginally conceived by me for a 10th grade science fair project last year, I started off with the baics, working mostly just to prove my concept. Pics under my profile......Primary propulsion is a G80 rocket motor, and then once in the air, wings unfold and it becomes a normal electric powered glider. At that point it was only RC with no onboard camera due to "funding" restrictions.In 2007-2008

However this year, working with a Lockheed Martin Engineer as my mentor, I optimized my aircraft by applying math to my design. Wings became high aspect ratio and fins changed shape and grew in area. With design changes made, I moved on to how to actually make it. Utilizing AutoCAD and Solidworks I designed many of my components in 3D to be cut by CNC routing, a vast improvement over the Scroll Saw that I had used in the previous year.In 2008-2009

Other improvements include 99% composite construction for durability and strength. The wings and fins were all covered with lightwight fiberglass cloth and have internal Carbon Fiber stiffeners, a lesson I had learned the hard way after the fins on a flying prototype "dissappeared" when they only had a small carbon support on the leading edge of them.

<</body>As for the electronics, the Guardian will be carrying an autopilot and wireless camera system this year. *knock on wood* I settled on the KX171X 900mHz 500mW Aerial Video System for RangeVideo and placed the order about a month ago, but the components have yet to arrive. So until they do I'm at a stand still except for flight testing which I should be conducting next weekend with high hopes. (videos soon after that) Working with the camera I have the RVOSD as a HUD for FPV flying. Then on autopilot duties I will end up using the RVOSD until my ArduPIiot has arrived and is assembled ;)

Hopefully within the next couple of weeks I'll finish up my testing and post so vids of it in action. After that its science fair in February, and I have my sights set on International Level at INTEL ISEF and try and win back some of the money I have put into this project :)Any feedback and recommendations are graciously welcome, as I will most likely due a continuation next year to finish my highschool research and maybe even take it to college with me...Cheers,Julian
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Math models for inertial navigation and selection of a microcontroller

Posted by ian on January 12, 2009 at 10:06am
I am trying to decide on a platform, but I would like to consider the math model being used, an the whether there is a need for floating point on the microcontroller.There are several models available for inertial measurements - some handling drop out of the GPS signal better than others, etc.. I'm trying to decide on a platform to control a multi rotor craft - quad or something similar to Jack's latest iteration using five propellers - but I'd like to have the option (if possible) to plop it into a fixed wing craft too. Paparazzi is the only system I've seen applied to multiple craft types.From a post by Jack Crossfire: "This is called an 'extended Kalman filter'. For best results, U need to integrate the gyros in quaternion form & blend in euler form. The ATMega autopilots don't do this because it's floating point intensive."Other versions of the Kalman remove the need to explicitly calculate the Jacobians an thus seem to require less cycles to compute, an still handle non linearities.Are most of the arduino an other lower power chips not using floating point dependant models (?). Perhaps there is a listing some where that I missed indicating the models used by different UAV platforms an the limits (if any) imposed by the microcontroller for floating point calculations (?).I know there are floating point libraries available for the Propeller, an the PIC's - but I wasn't sure if they were fast enough for inertial navigation models. Do any microcontrollers handle floating point on the chip?I saw this comment on another diydrones post: "Regarding the ARM CPUs (and the PXA used for the gumstix), Adam used these modules for his Vicacopter, but the lack of FPU yield very poor performance for the algorithms he wrote.The beagleboard is nice but it is also suffering from the same problem"However, my understanding of the Beagleboard is that the ARM8 gives it certain advantages over the 2148. Specifically "Cortex has a few unfair advantages over the LPC2148: raw clock speed, and VFP. VFP technology is a coprocessor extension to the ARM architecture. It provides low-cost single-precision and double-precision floating-point computation fully compliant with the ANSI/IEEE Std 754-1985 Standard for Binary Floating-Point Arithmetic.""The Cortex-A8 can calculate the square root of a single-precision floating-point number in 9 cycles. At 600 MHz, this is 15 ns. If you need double precision or full IEEE compliance (exceptions, fancy rounding, etc.), it can take up to 60 cycles (100 ns at 600 MHz). "How do the numbers on the ARM8 stack up against other microcontrollers that people have used?Thanks for any comments!
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ArduPilot code - now for MS Visual Studio plus parsing of Google Earth KML files

Posted by Michal B on January 12, 2009 at 4:30am
ArduPilot code, modified version for use on Microsoft Visual Studio. Compatibility with Arduino studio still maintained.Also contains parser of KML files, for importing fly paths drawn in Google Earth.Installation instructions:1) Download and extract ArduPilot_20090211.zip2) Download Arduino AVR studio3) Extract above into ArduPilot.vs\arduino-0012 folder4) If you don't have Microsoft Visual Studio 2005 yet, you can download free edition here (choose Visual C++ Express 2005)

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5) The code is still compatible with Arduino studio, simply run arduino.exe and open project from ArduPilot.vs\ArduPilot folder

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Build instructions under Visual Studio:- Open workspace ArduPilot.sln- Workspace contains folder "Source files" with ArduPilot code, this is where changes can be made

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- Another folder "System" is containing source files from Arduino studio needed to run ArduPilot executable, do not modify these- Build project as usual, if you see "Created ArduPilot.hex" in log window, then everything is OK

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- To upload to board, use Upload.bat from command prompt (you need to specify correct port in -P parameter)Note: if you change anything in *.h files, hit Rebuild Solution, because source dependency is not working in this caseWhy using MS Visual Studio for building ArduPilot code, when Arduino studio does the same thing?Well, if you're a programmer, then answer is clear - VStudio has better text editor, it will assist you in writing code by tools such as finding variable/function definition and declaration, text editor code highlighting, provides auto-complete, etc.Alghough we don't use C++ compiler from Visual Studio, rather custom build step is used with AVR compiler, mentioned advantages will help to make the code reliable and robust.On other hand, Arduino studio has very simple text editor, usable for the task, but if we have better tools, why not using them.Note: Visual Studio can be used on Windows only, so using Arduino studio makes sense for Linux/Mac users.How to use KML parser:This tool transforms KML file from Google Earth into ArduPilot friendly file.Usage:- In Google Earth, use Add -> Path (Ctrl+Shift+T)

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- Click to define waypoints

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- Do not connect last waypoint with first, it would create polygon which is not supported- Save the path in KML format (not KMZ)

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- Use KML parser to extract coordinates and create ArduPilot compatible file; the utility accepts 2 parameters - source KML file and destination H file; first is your KML path file from Google Earth, second is usually set to ArduPilot\waypoints.h, this will create waypoints file compilable by ArduPilot code. There's testing KML file as well as KML_test.bat file which puts proper parameters to the KML tool.- Compile ArduPilot executable and upload to boardSource code is provided for KML parser tool. It is compilable under MS Visual Studio, and runs on Windows.Problems and tasks:- Google Earth doesn't allow to define altitude for individual waypoints, or to export KML file with absolute altitude,so we end up with same altitude for every waypoints for now.We can fly on same altitude level, or manually tune altitude in generated waypoints.h file, or come with some other fix (suggestions are welcome).
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Cheap 6 Degree Of Freedom Inertial Measurement Unit

Posted by Cory on January 9, 2009 at 10:32am

I have finished my Master's Degree, and so I have to return all of the planes and paparazzi hardware which the school bought for my project. So I have begun working on my next project. So far I have purchased a cheap ($100 receiver ready + 2 free lipos!) 2 meter electric glider from Hobby City so that I can continue to fly. If it has enough space in the fuselage, then I may add an autopilot to it later. The glider will keep me flying, so my thumbs won't get too rusty.I am planning to rebuild my little ground robot, and I am going to give it a 6 DOF IMU. I found that Pololu(also available from sparkfun for similar price) sells a triple axis accelerometer for only $18 and 300deg/s gyros for only $29. So I can build a full 6 DOF IMU for only $110. So I have ordered 3 of the gyros and the accelerometer, and I am planning to build the IMU and run it on my little ground robot for a while until I have the IMU figured out. I am planning to use an arduino to process the IMU data.
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3D Robotics

AttoPilot's battery/motor sensor board now available

Posted by Chris Anderson on January 8, 2009 at 12:30pm

Another one from Sparkfun, which is quickly becoming a serious UAV parts supplier: the power monitoring sensor board that Dean Goedde uses for AttoPilot. If you want to add motor current and battery voltage measurement to your autopilot, this is a good way to do it. Analog output, so you'd want to add it to a port with an ADC (ArduPilot has six free ones so it would work well with that). Oddly expensive at $26, given what's on the board, but perhaps that reflects the low production run. Woohoo! Now $12.95! (and half sold out immediately). Go Dean!
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Help Wanted - Opportunity to map several large African cities...

Posted by Mike on January 8, 2009 at 4:03am
An opportunity to carry out aerial mapping of several large African cities using RC aircraft is being discussed. These discussions are at an early stage but if the project goes ahead then I am unlikely to have the time to do everything myself and will concentrate on the business side and managing the technical side. Anyone interested in getting involved please mail me at datapolo@yahoo.comBoth individuals and corporate organisations welcome.It is likely that we will be competing for the job against satellite imagery - not necessarily easy but possible. As an example one of the larger of the cities requires imagery within a 30km radius....Where we can compete is on resolution and maybe cost.If you want to get involved you need to be available to work flexibly and to be competent in all the necessary data acquisition skills - from flying, maintaining and repairing the platform to planning the flight paths and checking the data. Processing for mapping can be taught as long as you are very capable on a computer and have a good understanding of co-ordinate geometry and maps.I stress that this is all at an early stage and I will be meeting the client in-country in February to discuss in greater detail our capabilities and their requirements. Hopefully I will also be able to make a demonstration flight and show them what we can do.Look forward to hearing from you,Mike
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UAV Challenge - Outback Rescue will take place in 2009

Posted by Michael Molloy on January 7, 2009 at 9:58pm
We are pleased to announce that the UAV Challenge - Outback Rescue will take place in 2009 in the regional Queensland town of Kingaroy. The event will take place on 28 September - 1 October 2009.Aerospace students and enthusiasts alike will again have the opportunity to find and assist 'Outback Joe', a lost bush walker in Australia's vast outback, using UAVs.We look forward to your continued enthusiasm and support for this event.See you in Kingaroy!http://www.emailer.sd.qld.gov.au/em/mail/view.php?id=970246831&k=4ee7e9a
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3D Robotics

Another Sparkfun autopilot--this one with a full IMU!

Posted by Chris Anderson on January 7, 2009 at 9:30am

It's raining autopilots! Sparkfun has just released a new and much improved version of Bill Premerlani's original IMU-based autopilot board. The previous one was just a 5 DOF board, but this one has a full six degrees of measurement, with three gyros and a three-axis accelerometer. Also has a faster CPU and other goodies (see below). The code is open source and available in C (a big improvement over the assembly code of the first version). We'll be hosting the home page for the autopilot board here at DIY Drones, and you can now see it in the tabs above. I've set up a discussion forum here. If you want to move from a basic entry-level autopilot to a full IMU-based one and stay open source, this is a great way to go. IMUs are a lot more expensive than thermopile-based units like ArduPilot, but if you want full control they're worth it. This one is $299. Features: * Connection for a 20-Channel EM-406A SiRF III GPS Receiver (not included) * PIC dsPIC30F4011 Controller (with onboard 3.3V and 5V glue logic) * dsPIC runs at 120MHz with 16MHz resonator and PLL * MMA7260 three axis accelerometer * 3 ADXRS401 gyros * 4 Input, 3 output PWM points * 6-Wire ICSP debug header * 2 Separate colored status LEDs * 3 General purpose switches * On board 3.3V and 5V regulators (150mA max) * 10m Positional Accuracy / 5m with WAAS * GPS Outputs NMEA 0183 and SiRF binary protocol * Spare USART connection for debugging * 4 Spare digital I/O pins for debugging
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3D Robotics

ArduPilot now available to buy!

Posted by Chris Anderson on January 6, 2009 at 9:00am

Great news! ArduPilot is now available to buy at Sparkfun. The price is $24.95 (or buy 100 at $19.96 each ;-)). Note: there is a limited number available now, but Sparkfun can make more pretty quickly so get your order in now and they'll be filled from backorder in the order they were received.

[Update on availability from Sparkfun: ~15 coming out of production today/morrow. 63 more PCBs ready. Waiting on xtals (probably about a week).]

You'll also need an EM406 GPS module, and for all but the most stable planes, an FMA Co-Pilot, so unless you already have those items, the total cost of the autopilot will be around $155.

Huge thanks to Nathan Siedle at Sparkfun for helping us get through the production snafus and otherwise taking this project under his wing. Now let's win his autonomous vehicle competition with an ArduPilot-guided plane!

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T3

NXT AutoPilot v. 0.1 BETA

Posted by Sami Finnila on January 6, 2009 at 7:30am
UPDATE: 0.2 BETA and a simulator setup have been published HERE.So, here it is; one more BETA of NXT AutoPilot.I didn't have the time to do enough testing during the holidays so this is still going to be a BETA version instead of the non-BETA I promised. However, I caught some very nasty bugs in the stabilization loop and added some nice functionalities.// -Fixes in 0.1:// -Added variance (gyro vs. accelerometer) based coefficient for gyro drift fixing.// -Fixed some crucial GPS errors.// -Everything is now based on PID controllers (even yaw).//// -Still not using compass or barometer although the device driver for compass is still there// if you don't mind some home brewing..TO-DO:-Navigation still assumes GPS co-ordinates to be co-ordinates on a flat surface. Introduce ball geometry..-I'm planning to buy a 3D Bluetooth GPS so alternate device driver and control loops are needed.-Documentation.Hopefully someone finds this useful..NXT AutoPilot v0.1b.zip WARNIGN: This version of the auto pilot is out dated!Sami F.
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A long-held ambition

Posted by Steff Davies on January 4, 2009 at 7:34am
When I was a small boy, I used to watch the Jindivik target drones take off from Llanbedr (see http://www.airsceneuk.org.uk/hangar/1999/dera/targets.htm) on family holidays to North Wales, where my father was born. I've been interested in unmanned flight ever since.Currently, I have built nothing whatever in this line, but I have done a lot of reading (not least here - thanks Chris!). Ultimately, I'm thinking of a small electric fixed-wing based on a simple kit like the Multiplex Easy Star or Twinstar. My current thoughts on the rest of the kit:Mainboard: Gumstix OveroThe familiar Linux environment is too tempting to pass up, I think (I'm a Linux/BSD sysadmin by trade). Also, the surplus of CPU horsepower means that I can concentrate on getting something working in a scripting language and then making it faster rather than having speed as a constriction from the outset.Servo control: http://www.seetron.com/ssc.htmcheapish and lets me outsource the servo-control nastiness (of which I know very nearly nothing) in favour of talking to a serial port, which is more familiar territory.GPS: A 5Hz GPS module of some sort - there's a San Jose 32-channel on sparkfun which looks impressive. It appears to do serial output over two pins at 2.8V.IMU: I think this is going to have to be the Sparkfun 5DOF. I simply don't have the electronics chops to build my own, and anything nicer is going to cost too much for a first go-round.Telemetry: at least initially, wifi looks like the way to go. Unfortunately, the Overo currently lacks a wifi implementation, but there's a known-working USB dongle.This gives me a functional diagram like this:

Some Unresolved Questions (in no particular order):1) Serial connections. The Gumstix Summit board claims two "2-wire serial" connections - are these right for direct connection to the GPS module? To the servo controller board (I suspect not in this case)?2) Are the AD convertors on the Overo accurate enough (10bit) to be useful?3) Are they electrically compatible with the output from the IMU in any case?Have got the wrong end of any very important sticks? Have I made some glaring omission? I throw myself on your mercy.
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Thrust and Payload ? (X3d-BL+Hacker A20-22l Outrunner

Posted by Kedar Kulkarni on January 4, 2009 at 12:24am
We are making a Autonomous flier (quad rotor based) which will carry Sensor system(LIDAR,INS etc) and a camera; and is capable of obstacle avoidance and precise hovering.We have narrowed our search for a quad rotor flier to 'X-3D- Scientific' as our base model of which we will change motors,propellers and battery.We plan to change the motors with Hacker A 20-22l outrunner and the standard propeller of 10*4.5 and also the battery with a 5000/6000 mah for higher flight time (about 10 mins).Certain queries:1. Will the flier with new configuration and total weight of 1433gm produce enough thrust (about 1.8kgs) ?2.Is X-3d best one around?3.Do we have better motors (producing more thrust ) ?4. Is 6000 mAh correct estimation of the Battery type?
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3D Robotics

New BlimpDuino board (final production version)

Posted by Chris Anderson on January 2, 2009 at 7:30pm

Here's the final board (v6) that will be going into production (click for big picture). No big changes and it's pin compatible with all boards since v431, so all current software will run the same and there's no need to upgrade for people with boards since v431. The main thing was better labeling and other cosmetic changes, but here's the full list. * Even smaller! * Has holes in the corners so you can screw it onto the gondola * Optional extra pair of pull-up resistors (R9 and R10) on the I2C port, in case you want to add more sensors • Fully labeled, including part numbers * SMD power regulator, smaller and easier for mass production. * Added an extra pair of .1uf capacitors in the motor ports to reduce noise. * Added a solder jumper (very tiny) so you can select if you want to read the ultrasonic sensor in analog or PWM mode. • Changed labels north, south, west and east to front, back, right and left. • Solder jumper to the 5 volts of FTDI cable (so you can power it from the FTDI if you want) • Better traces • Changed the ICSP position (the port was a little too close to the IR sensor on the previous version, and it was hard to get a connector in there) • Power switch before power regulator and motor controller. (the power switch was after some electronics in the previous version, which could slowly drain and kill a LiPo if you left it plugged in long enough with the switch off) You can buy the boards here Eagle 5 PCB and Schematic files are here. Assembly instructions and component lists are unchanged from the previous version.
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3D Robotics

BlimpDuino code Beta1.1 released

Posted by Chris Anderson on January 1, 2009 at 1:30pm

Jordi's now finished the Beta release candidate of the BlimpDuino code. Lots of goodies:

  • Full PID loops in both altitude hold and navigation
  • Autosenses if a RC receiver is connected and switches into RC mode
  • Voltage monitoring cuts off power to save LiPo when voltage is low
  • Fully proportional vectoring servo control
  • Goes into altitude-hold-only mode if beacon signal is not seen
  • Code better commented and easier to read
The source code is now located in a proper Subversion repository on Google Code. This version reflects the current operating instructions, both for assembly and flight (RC and autonomous). They've been updated, so if you haven't checked them out recently, please do.
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