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3D Robotics

Arduino meets Android

Posted by Chris Anderson on January 22, 2010 at 9:57pm
Check out Amarino, which is a toolkit to connect Android phones to Arduino microprocessor boards. Described as "basically consisting of an Android application and an Arduino library which will help you to interface with your phone in a new dimension. You can build your own interfaces almost without any programming experience."
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3D Robotics

Size comparison: ArduPilot Mega vs ArduPilot

Posted by Chris Anderson on January 22, 2010 at 4:30pm

Many of you have asked for a side-by-side comparison of ArduPilot Mega and basic ArduPilot, so here it is. Note that with Mega, we moved the servo and GPS connectors to horizontal rather than vertical placement, to make them more robust in the case of a crash. As you can see, the main processor in ArduPilot, an Atmega328, is just handling RC input and the failsafe function on Mega, while the main CPU has been upgraded to an Atmega1280, with more than twice as many I/O pins. In a sense, every chip has been upgraded to their big brother on Mega to handle more channels, sensors and communications paths. Basic ArduPilot, especially with the Turn-Rate Limiter Shield, will continue to be sold and will be the best plug-and-play solution for newcomers, while Mega will offer more capability for more advanced users.
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Developer

Do you want an ArduPilotMega board? (Limited)

Posted by Jordi Muñoz on January 22, 2010 at 2:30pm
I know some of you want to help and also for those that can't wait to put their hand's on the ArduPilotMega board here is your opportunity: You can be a Beta tester!The final version of the board will almost the same, just some small corrections like an extra set of resistors pads i added just in case that will be removed in the final version, right now are just bypassed.The requirements for being a beta tester are:-Have and know how to use an AVR ISCP Programmer (i recommend the AVRISP MKII), to upload new HEX's just in case we decide to change the PPM encoder firmware.-Windows XP/Vista/7.-Have a FTDI cable programmer.-Know how to use Arduino Environment and some basic programming skills.-Have a clue what digital electronics means (If you are a regular user or a certified noob, i don't recommend this board to you right now).-Willing to share your experience!-Have $38.90 dlls $44.90, i'm giving the board almost to the production cost (for low quantity's). The final version may cost up to $65 dlls!If you are ok with all this, you are welcome to get one board right now:http://store.diydrones.com/ProductDetails.asp?ProductCode=BR-ArduPilotMega-01The boards come with firmware (for AT328) and bootloader (for AT1280).I will be posting news&updates on the comments.I have a basic firmware that reads and decodes the PPM signal and display the 8ch PWM's into the terminal:APM_demo.zipThe folder "PPM_Decoder_AT1280" is located the code for Arduino IDE. On the folder "PPM_Enconder_AT328" is the firmware for the PPM enconder, if you have Windows and the AVRISP MKII just double click on the .bat file and press any key and it will upload the hex to the board, make sure to connect your programmer on the "AT328 port".PPM Encoder configuration:-MUX is controlled by input CH5.-Throttle FailSafe is input CH3 (Futaba).The Eagle Files of the Board are here:ArduPilotMega_v10.brdArduPilotMega_v10.sch
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Moderator

Atto Jack in the Box

Posted by Gary Mortimer on January 22, 2010 at 12:29pm
Chris Mc Nair has been playing about with things.

Boomerang flying wing UAV parachute failsafe hatch test. from Gary Mortimer on Vimeo.

To be fired by the Millswood crashinator, and oh so close to an off the shelf OBC airframe!The first thing to be added whilst thinking about what actually might be allowed, the second thing is being added but now there's a new second thing so that might make it a third thing.All a bit of a secret.The crashinator can also control cameras!
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THIS WEEK IN MARCY 1 AVIATION

Posted by Jack Crossfire on January 22, 2010 at 1:27am

Decal applied.

Ground station packed in. Battery sensor calibrated.

This design did not achieve horizontal control. The pitch oscillationfrom not having enough balance beam inertia offset any horizontal force.

This redesign did achieve 2 horizontal changes of direction using onlythrottle modulation. Unfortunately she threw a propeller &disintegrated upon crashing.

Marcy-1 was already very prone to throwing propellers, her 5300kV motorseemingly at the limit of Chinese plastic. We have a 4' monocopterplanned for extremely long duration hovers with normal RPM.There it is. XYZ positioning using only throttle on the Marcy 1 vehicle.Unfortunately not enough authority to move upwind, so we only gotcrosswind translations & a slower downwind drift than if cyclic wasneutral.As Mike Bakula recommended, used raw magnetometer output & detected whenthe halfway point in the waveform was crossed. Much better than usingderivatives like MIT since the derivatives are very noisy.Very important to have the balance beam loaded as much as humanlypossible to prevent pitch oscillation. Having the motor & battery onthe balance beam is the easiest way to load it. She did indeed bank inthe direction of the translation from throttle alone.An aileron servo would do better against the wind but it would be heavy,expensive, & wear out fast. No way a servo would cycle 6x a second forvery long. If you're gonna use 2 PWM, there's no point in a monocopteranyways but it's probably unavoidable for any long duration, outdoorvehicle.PROPELLER TERRORISMFinally got a flight in no wind & drizzle & she was easily controllableusing only 1 PWM. She was very sensitive to breezes.1 problem was power level changes when applying cyclic which we actuallylearned to handle. Greatest horizontal thrust comes from gliding herwhen applying cyclic. You can stall the motor this way so she justapplies thrust in 1 direction yet stays in the air. Greatest verticalthrust comes from releasing cyclic. Power management on a monocopter isa new artform.

The mane problem was broken propellers after 6 minutes. That's right.The GWS 3x2's are just not strong enough to provide hovering power.Marcy 1 is perfect in every way but dead without a stronger propeller.Ideas range from griding them down to 2.5x2 & using 3x3 if the weatherever improves.

3x2 ground into a 2.5x2SONAR REVIVALGetting sonar working on a new flight computer & new radio is nevereasy. The mane problem is actually the microcontrollers & tools. Everynew microcontroller has a different register set. If you want SPI,magnetometer, & 3k of RAM that means capture compare & analog need to berewritten.Also, the MRF49XA takes so much more CPU time to service than the XBee,sonar had to go on a dedicated USB device, making it more expensive touse 8 bit PICs than 32 bit ARMs.3 years ago ARMs were $10 & really tough to solder. Now they're $2 &easily soldered. PICs are only still around because of code reusethough ARMs need a lot more pins for programming.Building a 100Mhz computer from scratch using an ARM has always beenalluring, but the only motivation now would be going back to embeddedautopilots or a huge price advantage with ARMs.SONAR THEORYThe trick with sonar is to synchronize the clocks on the ground station& aircraft. Vika 2 did it by sending 1 beacon to the ground station &aircraft simultaneously. Marcy 1 doesn't have sonar on the same USBport so there's a significant rewrite already.

The complete Marcy 1 sonar guided kit, applying all the sonar knowledgegained from Vika 2.

The standalone sonar board is the simplest possible.Now more views of the machine with 3x2's & loaded balance beam.

Sonar installed, magnetometer in the stock & this thing which tellstime. Wow that sounds neat.

Making the sonar crash resistant is going to require a new fuselage.

Aren't you glad you didn't need to solder this. This is standard forChinese toys though not Air Force grade except for the name.

Balancing act.

Final look before crashing.
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Setbacks and Batteries

Posted by Jason Lyons on January 21, 2010 at 7:09pm
Well, after playing more with the IMU, the roll gyro has stopped working! I performed a visual inspection of the breakout board, and didn't see any shorts or signs of arcing. I reworked all the solder joints, making sure none of them had come disconnected. Finally, I removed the gyro daughter board from the IMU and tested it on its own, still no luck. The self-test function also is not returning anything, so I think it's stuffed.What a pain in the ass! Just as I was starting to get somewhere with the Kalman. Fortunately Sparkfun have offered to take a look at it and see if they can figure out what's wrong (and perhaps replace it!), as at the moment I can't afford buying any new sensors ($30 shipping every time is a killer!). If I have to buy a new one, I guess I'll have to wait until I have enough cash for a GPS unit, magnetometer and TTL->USB board as well so I don't get nailed for shipping twice.In the mean-time, I ordered some LiPo batteries for super cheap off ebay (E-Fly 2S, 900mAh, 15C), 3x batteries for $10! And only $10 shipping (from Hong Kong). I know what you're thinking.. never buy cheap & nasty batteries, but this is a low-budget project. I'm hoping these batteries will replace the 8.4V 650mAh NiMH batteries that my helicopter has been flying off, and that the weight saving will give me a bit more leeway with my autopilot payload. The only thing that I am concerned about, is that if these LiPos have built-in under-voltage protection (ie. switch off after reaching 3V per cell). Is that standard on all LiPos these days? Being a no-name brand, I couldn't find any specs on the batteries themselves..If I can sort that out, hopefully I can blow the dust and cobwebs of the heli and get some flights going this weekend to re-balance the helicopter and trim it right up.
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Turn Rate Limiter Shield Preview

Posted by Jeff Taylor on January 21, 2010 at 2:00pm
This is the first working version of turn rate limiter starting beta testing now!For those not familiar, this is a project aimed at providing a cheap, easy to use shield for beginners. It only requires this board and the ArduPilot main board to fly the plane, very simple!

I got only a mild version of Jordi fever, only the pressure sensor was affected :D

That gyro is so small!!!
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XDuino - 32Bit ARM-7 Cortex-M3 MCU with Arduino-compatible syntax and similar IDE

Posted by Jonathan Lussier on January 21, 2010 at 10:52am
Website: http://www.xduino.comPrice: 30$ + 10$ shippingInfo:http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1248633489http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1247691841http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1257646436I think this board would be a great replacement for the arduino, esp in tasks such as ardupilot, arduimu, etc where limitations are present (ie Kalman filters are too slow, ROM is too small, etc). A huge benefit here is also that there are two DACs (not PWMs, real DACs!) and not only that, but they're 12-bit. The ADCs are also 12-bit, compared to the Arduino's 10-bit ones (and there are 16 ADCs vs. 6 on the Arduino).This board is SMT only which I think is reasonable (and lighter weight as well).The board features: (from the website)Bootloader via RS232 (not USB) (which saves weight)32Bit ARM Cortex-M3 running at 72MHz 64Pin (LQFP) by STmicroelectronicsUse Crystal 8.00MHz + Phase-Locked Loop (PLL) - computes at 1.25 DMIPS/MHz to process data that is equivalent to 90MIPSHas RTC (Real Time Clock) Circuit with XTAL 32.768KHz and Battery Backup connector5 Serial ports48 General purpose input/output pins (GPIO)16 Analog input channels 12-bits (ADC)2 Analog output channels 12-bits (DAC)512 Kbytes of Flash memory68 Kbytes of RAM3 SPI ports (2 can do I2S)2 I2C1 USB1 CAN1 SDIOSupports In-System Programming (ISP) and In-Application Programming (IAP) through On-Chip Boot-Loader Software via Port USART1 (RS232)Has RS232 Communication Circuit that uses Connector 4-PINHas 48 Bit GPIO with 5V-Tolerant for independent digital applications (maximum analog input is 3.3V)Use +3.3V Power SupplyConnectors is placed on 50 Pin Header with a distance of 2.54mm (100mil) (25 pins per side) with a distance of 1.5 inch (1500mil/38.1mm), so it is quite easy to use and expand I/O Circuit.Any thoughts?
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Stabilization of RC Helicopter with NeuroFuzzy networks

Posted by Aldo Vargas on January 21, 2010 at 9:30am
Hi everybody!!!I'm making a stabilization system for a helicopter, hehehe, another one...First of all i want to show my hardware:- ArtTech Falcon 3DRotor Diameter: 24.8"Tail Rotor Diameter: 5.98"Weight: 19.5 oz.Length: 26.4"Servos: 4 9g servosTransmitter: 6 channel 72MHzReceiver: 6 channel dual conversionBattery: 3S 1300mAhr 10C LiPoMotor: Brushless B20/10TESC: 18A Brushless

- The great Arduino as Avionics- IMU 6DOF Razor ( http://www.sparkfun.com/commerce/product_info.php?products_id=9431 )- Small arduino shield build by me, just with the purpose of holding and connecting the razor to the arduino.Software:- DCM modified by Automatik, 10x a lot man!!! ( i had made some modifications, for making the arduino control servos for pitch and roll)- LabView VI made by Automatik, 10x again man!! ( with a little bit of modifications )What have i done so far:- I've had a lot of problems with vibration!!!! its the thing that had stop everything!!!- We try several configurations, with foam, and other stuff.- The configuration that work the best, its a base with rubbers and velcro, a little hard to explain in english, so ill just paste a picture....

In this picture, the heli is showing the base, and you can see the rubbers.

You can see the shield and the arduino, mounted inside the landing gear.

You can see the usb port, its on the back of the heli.

I just uploaded a video, with the first test with the rubbers and velcro, sorry, its in spanish, because it was for my faculty advisor, hehehehehttp://diydrones.com/video/instrumentation-with-rubbersVibration Issues:In the next pics you can see the problems i had with the excesive vibration produced by the helicopter, and this issue make the stabilization impossible!!!! Because the angles are completly crazy!!!This test was conducted with the DCM filter and half throttle.

This test was conducted with the kalman filter and half throttle.

What do i want right now??In this moment i just want to focus on stabilization, and mainly in pitch and roll, i will not take care of yaw...Any help, comment will be greatly appreciated!!!10x a lot!!Saludos!!
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Developer

Replacement for the SuperStar EP Select

Posted by Doug Weibel on January 21, 2010 at 7:19am
The Hobbico SuperStar EP Select is one of the two recommended airframes for ArduPilot and it has been a good choice providing a nice "high wing aileron trainer" at an affordable price. Unfortunately, it has been discontinued for some time and a recent check finds them near impossible to source any more.I have looked around for an equivalent replacement. One I found suitable is the Hobbico NexSTAR Mini EP, which is more or less Hobbico's replacement for the SuperStar EP Select.

lhcaa0700.jpg

It is sold either as a ready to fly package with a 2.4 Ghz radio or as a receiver ready package. Tower Hobbies has these two for $270 and $180, respectively, and Tower usually has a coupon out which will give you $15 to $20 off. Just google "tower hobbies coupon discount". Replacement fuselages, wings, and tail surfaces are also available. While the receiver ready price is 50% higher than what we were paying for the ARF Superstar, the inclusion of a brushless power system and servos makes the price a reasonable value.I received a receiver ready kit today and have inspected it. Apart from the covering being a bit wrinkled, which I think is a Hobbico trademark, I am pretty happy with the quality. See pics below comparing the SuperStar and NexSTAR.While it is nearly as long as the SuperStar and has just a bit less wingspan, the chord is substantially less and the weight is substantially less. Since it is designed for a brushless/LiPo power system the reduced wing area is appropriate. The fuselage width is adequate for UAV purposes. You can see the Mega board inside the fuselage in one pic below.Things I like:* It is a "receiver ready" kit, so it is very complete. About all you need to fly it is a TX, RX, and battery.* Fuselage is plenty deep so no issues with interference between AP gear and the aileron servo arm and pushrods* The wing ribs all have lightening cutouts so fishing a pitot line to the outboard leading edge will be much easier.* Steerable nose wheel, servos, brushless motor and esc all come pre-installed.* A good wing attachment system using a nylon bolt and a fitting that allows flex in a crash.* Reported flight times of 15 minutes on a 3 cell 2100 mAh LiPoThings I didn't like:* A balsa shelf will need to be added for the AP as the shelf for the RX is small. An additional shelf will provide a nice large area for the AP, but it will be under the rudder and elevator control rods so hooking up wires will be a bit fiddly.* A little smaller than I expected.I am short on receivers today, so I probably won't fly this for a week or so, but will post comments when I do.

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Podcast Episode 14 - Henri Seydoux, CEO of Parrot (makers of the AR.Drone)

Posted by Tim Trueman on January 20, 2010 at 9:47pm
iTunes linksAAC: http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewPodcast?id=330632997MP3: http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewPodcast?id=330633212RSS feedAAC: http://feeds.feedburner.com/diydronesMP3: http://feeds.feedburner.com/diydronesmp3Henri Seydoux is pronounced "On-ree Say-doo" (I believe, correct me if I'm wrong).
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3D Robotics

Congrats to the winners of T3-4!

Posted by Chris Anderson on January 20, 2010 at 3:55pm

The High Chief T3 Judge, Gary Mortimer, has ruled, and the above are the results of T3 Round 4, photo-mapping a quarter kilometer. Brakar was the overall winner, but everyone listed did a great job. A very impressive crop of entrants--congrats to you all. Because all the submissions were excellent, everyone will get a prize of some sort, but the grand prize will be an ArduPilot Mega beta unit. (This is either a blessing or a curse, depending on how many bugs we find on those boards. But so far, it's looking pretty good)
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3D Robotics

T3-Round 5: Virtual Sparkfun competition!

Posted by Chris Anderson on January 20, 2010 at 2:00pm


For the fifth T3 (Trust Time Trial) contest, we've got an easy and fun one: set the best time for a virtual Sparkfun Autonomous Vehicle Competition course. The real Sparkfun contest will be held on April 17th in Boulder, Colorado, and is simply the fastest time for an autonomous vehicle to do one lap around the company's headquarters (shown above). The DIY Drones team won it last year in a time of 35 seconds, and we (and other DIY Drones community members) will be entering this year, too.

Your mission is to program your UAV to fly a pattern around a rectangle the size of the Sparkfun HQ (dimensions shown above). One lap, fastest time wins. The rules don't say anything about takeoff or landing, so you can cross the start line (shown in the picture) at full speed and it doesn't matter what happens after you cross the finish line. Altitude is up to you, but stay below 400ft, as always, and I'd recommend staying above 100ft to avoid the evil trees!

I expect that competition will come down to fractions of a second. Since most GPS loggers only record a position once per second, you'll need to interpolate between timestamps for both the start and finish time. The way to do this is to draw a line from the pointy bottom tip of two adjacent Google Earth pushpin markers. Estimate how far along that line the start or finish lines cross, and apply that fraction to estimate the real time. This illustration gives an example:


Please show these calculations on your KML path image.

BTW, it would be cool to have a model of the Sparkfun HQ to place in Google Earth so you can display your path around a "real" building. Your Chief T3 Judge, Gary Mortimer, has issued a call for a volunteer to make that model, so when one of you rises to the challenge I'll post it here for all to use.

Same submission rules as always. Submit time, autopilot and airframe, and KML track (both screenshot image and raw data) as evidence in the comments below. Video very much appreciated but not required.

Deadline Wed, March 14th, 12:00 midnight PST.

Gentlemen, start your engines!
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3D Robotics

[RESCHEDULED FOR TONIGHT] DIY Drones live chat/podcast with AR.Drone inventor Henri Seydoux, Tuesday night at 9:00pm PST

Posted by Chris Anderson on January 19, 2010 at 3:00pm
Free video streaming by Ustream [UPDATE #2: Okay, we're back on. This is going to happen tonight (Tues). Thanks again for your patience on this one!] On Sunday Monday Tuesday night we'll do podcast #14, which everyone here is welcome to participate in by listening to the chat live above and commenting and asking questions via the DIY Drones chat function. We'll be starting at 11:00 6:00 9:00 PM PST and will probably go about 40 minutes. This week we'll by joined by Henri Seydoux, CEO of Parrot, the creator of the awesome AR.Drone semi-autonomous quadcopter. Apologies for the late hour of the podcast this week, but it's to accommodate the fact that he'll be calling in from Paris. This one is worth staying up for! As always you can subscribe to the podcast here. Tonight's livecast will be recorded and available as a podcast on Monday.
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