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The PX4 team is pleased to announce early availability of the PX4 autopilot platform, with hardware available immediately from 3D Robotics. 

The platform is a low cost, modular, open hardware and software design targeting high-end research, hobby and industrial autopilot applications.

PX4 is an expandable, modular system comprising the PX4FMU Flight Management Unit (autopilot) and a number of optional interface modules.

The PX4FMU autopilot features include:

• 168Mhz ARM CortexM4F microcontroller with DSP and floating-point hardware acceleration.
• 1024KiB of flash memory, 192KiB of RAM.
• MEMS accelerometer and gyro, magnetometer and barometric pressure sensor.
• Flexible expansion bus and onboard power options.

Expansion modules available at release include:

• PX4IOAR This module interfaces PX4 to the AR.Drone motor controllers, allowing a complete quadrotor to be assembled using an AR.Drone frame and motors.
• PX4IO A flexible interface module with support for eight PWM servo outputs, relays, switched power and more.

As an open hardware design, third-party and DIY expansion modules can be easily developed for specific applications, and more PX4 modules are in development.

In addition to the versatile hardware platform, PX4 introduces a sophisticated, modular software environment built on top of a POSIX-like realtime operating system. The modular architecture and operating system support greatly simplify the process of experimenting with specific components of the system, as well as reducing the barriers to entry for new developers.

Adding support for new sensors, peripherals and expansion modules is straightforward due to standardized interface protocols between software components. Onboard microSD storage permits high-rate logging and data storage for custom applications. MAVLink protocol support provides direct integration with existing ground control systems including QGroundControl and the APM Mission Planner.

Pricing of the PX4 components reflects more than a year of careful development and a strong commitment from our manufacturing partner.

• PX4FMU: US$149
• PX4IO: US$99
• PX4IOAR: US$89

This release is targeted at early adopters and developers looking for a more capable platform than existing low-cost autopilots. With more than an order of magnitude more processing power and memory compared to popular 8-bit autopilot platforms, PX4 is exceptional value for money and provides substantial room for future growth.

For more information about the PX4 autopilot platform, visit the project website at http://pixhawk.ethz.ch/px4/

PX4 modules can be purchased from our manufacturing partner, 3DRobotics.

I noticed that Chris posted a while back about the use of an Arduino in an R/C car.  I've haven't posted anything here about my project as it's not autonomous, doesn't fly, and isn't really a drone.

It does, however, borrow code from the ArduIMU for the sensor fusion so perhaps someone may find it interesting.  "Normal" r/c motorcycles (yes, they do exist and are far more popular in Europe) use a loose spring linkage between the steering servo and the forks.  This allows the geometry of the bike to do the balancing and the servo can just nudge the bike to lean to one side (using counter steering.)  

My solution uses a more rigid servo connection driven by the output of a PID control.  The operator's steering input, the IMU's roll angle output, and the forward velocity of the bike are used to compute the steering angle to hopefully maintain balance while providing steering control.  Works well on road - real objective is for off road though.  

“We want to build small-scale UAVs that can fly quickly through indoor and/or cluttered environments, but controlling these UAVs is very different than controlling a fighter jet flying up above the clouds,” said Dr. Russ Tedrake, X Consortium associate professor of electrical engineering and computer science and aeronautics and astronautics at MIT and the MURI lead. “To be successful, we have to solve a number of incredibly hard problems in computer vision and nonlinear control. This long-term project lets us focus on the basic research questions that will lead to fundamental results and, ultimately, dramatic new capabilities for UAVs.”

Full press release

http://www.suasnews.com/2012/07/17753/birds-perceptual-and-maneuvering-abilities-inspire-small-unmanned-aerial-vehicles/

Well, I'll use this bird to keep track of which way my quad is pointing....

Parrot AR Drone (TM) anyone?

Hi Everyone,

Chris Gammell of The Amp Hour here. We had a chance to interview Chris Anderson last week and it was great hearing about the DIY drones community. He was a wonderful guest and I thought some people here might enjoy hearing what he had to say. I'm also happy that talking to him converted me from a lurker (I check the "Everyone's Posts" RSS feed every day....love the FPV videos) to finally becoming a member. I look forward to participating!

http://theamphour.com/2012/07/23/the-amp-hour-105-deambulatory-daedal-drones/

~Chris Gammell

Announcing: ArduCopter 2.7

In just a short while, ArduCopter 2.7 will become available for download in Mission Planner. As we worked on ArduCopter 2.6.1, we saw that it had several new and compelling features (as well as many bug fixes and improvement) so it was decided to make this a major version release. 

A full list of changes is here, but they include:

New and Improved:

Bugfixes:

• Fix to dataflash erasing, which should resolve an issue some users were having
• Fix some MAVLink commands
• Fix Circle command
• Fix some units
• Etc

Notes:

John Wiseman and I have been working on the browser-based frontend for Mavproxy which he announced a few weeks ago. Here's a new demo video I made controlling an ArduCopter:

Heres a screenshot of the new and improved user interface with PFD:

We're actively developing on Github. You can start using Mavelous today!

Hi all,

I wanted to ask some questions about my quad implementation but I thought that it would be polite to introduce myself and my quad first.

I started my first quad design because my wife and I (and two kids under 2) were planning a 2 week four wheel drive trip across the Simpson Desert in central Australia. For those not familiar with the Simpson Desert it is 550 km of desert, 1100 sand dunes to cross, and 3000 km round trip. The quad seemed like the perfect way to get a different perspective on the landscape.

I have been following DIY Drones for a while because I supervised a couple of Electrical and Electronic Engineering final year projects to develop an IMU for a basic auto pilot application. So I ordered an ARM 2 and a bunch of parts from Hobby King.

I started with a cheap frame but quickly realised that it wasn’t going to be easy to mount the ARM 2 so I decided to design and build my own, keeping the aluminium arms and motor mounts. I wasn’t overly happy with my first design but it did serve to introduce me to some of the basic tuning and setup required. It also made me realise how much electronics I was going to have to cram into the quad to do what I intended.

I quickly realised that my first frame was going to be very difficult to carry in a fully loaded 4WD so I redesigned the frame to fold up and be stored against the cargo barrier above the rear seats. I also added some room for a pitch gimbal on the GoPro I intended to use.

The final assembly looks like this:

Folded for travel:

And the pitch gimbal and GoPro:

The basic parameters for the quad are:

1.6 kg with GoPro

NTM Prop Drive Series 28-26A 1200kv / 250w

APC 12x3.8 Propellers

Hobbyking X550 Aluminum Spare Booms ( 2pcs red/2pcs black)

ZIPPY Flightmax 4000mAh 3S1P 20C

Fat Shark Predator RTF FPV Headset System w/Camera and 5.8G TX

I broke quiet a few prop’s so I am now using:

Slow Fly Electric Prop 1045 SF

In the end it took four full days from start to finish before I left on the trip so I had very little time to learn to fly a quad and optimise the tuning. I have flown RC gliders since I was 14 so I had some basics but this was the first time I had flown anything with a motor. The most challenging part of the process was the tuning. I have a good understanding of control theory as make use of it from time to time in my day job but the Wiki control loop diagrams don’t seem to be up to date. This made it difficult to understand how some of the parameters interact.

I didn’t get to develop my flying skills too much before I left and I only started to get comfortable flying FPV near my last flight of the trip. Unfortunately I missed one of my ESC connectors worked its way out and I crashed the quad after approximately 10 flights. I some good footage though. I will post a video when I get one cut together.

I would like to thank the DIY Drones community and everybody who contributed to the ARM 2 board!

Sparkfun has released its recap video of this year's great Autonomous Vehicle Competition. It was a great weekend for us, and a huge amount of fun, as you'll see. APM-powered vehicles won the air and ground category (the latter using custom-code), and the next day's Multicopter Competition, too. Really proud of all the teams. 

I've had quite a few positive comments, and also, some folks have pointed out bugs and made suggestions for improvements.
So, I fixed the bugs (all that I know of anyway), added most of the suggested features, and added a couple new features of my own.

Above is a YouTube Video that shows most of the features, and how I narrowed down the reason for my crash.

Here's the latest software:
http://siderealtechnology.com/APMLogVisualizer1.32.zip

In the following YouTube video, you can see the crash, as I had my GoPro on the copter:

We were huge fans of the original EasyStar back in the day: it was tough, flew well and had loads of room for electronics. But it was slow to evolve (terrible brushed motor, no ailerons, rudder too small) and our favorite beginners platform shifted to the Bixler, which came almost ready to fly and was much cheaper than the EasyStar. Last year, however, Multiplex released an EasyStar II in Europe, but it's only just now arrived in the US. So I bought one and put it together and flew it for a review here. 

First, the good news: 

• Built-in ailerons
• Excellent power pod allows for easy access to the motor. Designed for brushless motors
• Folding prop
• Easy-to-remove elevator for easy transport
• Better ventilation
• Bigger rudder

Now the bad news:

• Expensive. $95 without motor, servos, or ESC (compare that to the Bixler, which is $58 with motor and servos already installed)
• Hard to assemble: It basically arrives as bags of plastic and foam. Expect at least two evening to assemble. The Bixler, by comparison, goes together in about an hour, in part because the motor and servos are already installed.
• Although the cockpit is longer than the EasyStar I, it's also narrower (by about 3-5mm), which makes for a tight fit between batteries and electronics. 
• Nose-heavy, perhaps because of the longer nose. You'll have to push your electronics as far back as possible, and if you use a battery bigger than 2200mah, you'll need to add weight in the tail. 

Bottom line:

I was not as impressed as I'd hoped. Overall, I still prefer the Bixler for new users. I think the EasyStar II is too expensive and too hard to assemble, and requires ordering motor/esc and servos separately, which will confuse beginners. (Multiplex usually sells an optional power pack, which is a very expensive motor/ESC combo, but has not yet released that in the US. The one for for the old EasyStar, which may work, costs $80!). The EasyStar II flies well, but not noticeably better than the original EasyStar or Bixler in my limited testing. 

Now that I've bought the EasyStar II and set it up, I'm happy with it and it will be my main plane for APM 2 testing. But on balance, it doesn't represent enough of an improvement over the Bixler to justify upgrading. And remember, there's a Bixler 2 coming, too.  If Multiplex were to ship the EasyStar II with motor, ESCs and servos for under $100, I think I could recommend it, but for now I don't think it represents enough value and simplicity for new users.

I recently showed an interest in supporting Cheap Drones over Hobby King in this thread, since Cheap Drones is a small company and I'm always glad to support them over big business.  Cheap Drones sent me a freebie gift since I'd shown interest in their products.  Now I was expecting maybe a t shirt or a lanyard, so I was shocked when I got an FPV Raptor kit in the mail!  All I can say is that Cheap Drones has a customer for life; I intend to buy all the FPV and plane equipment I need from them.

After coming back from my honeymoon I finally found some time to get some real flights. 3 weeks ago I flew my copter for the first time but it was just a few minutes on a very low altitude in front of my block. Today I went to some open space. Unfortunately, the wind was very strong so learning changed into fighting with the wind. Still managed not to crash the copter and even attached GoPro to it :)

Here you have 4 exceprts from those flights.

Comparing http://code.google.com/p/arducopter/wiki/AC2_ModeSwitch with APM Planner need to ask what is the "Toy" mode not described on wiki?

Also, is it possible to make some sound (by using ESC/motors?) when arming/disarming? My LEDs are hard to see under the shield (anyway, are LEDs shows arming state? on wiki couldn't find that info) so some audio notification would be appreciated. Audio info on GPS fix will also help a lot. I'll check for some hack connecting the buzzer. Still a newbie here :)

Except "stabilize" mode I tried to use "loiter" and "alt hold" but probably due to the strong wind I had problems with having proper control over my copter. RTL was also fast drifting with the wind far over home location so had to switch to stabilize to recover the copter.

On next session I'll try "simple" and "super simple" modes. To bad they can't go paraller to check them without connecting to APM Planner to switch "SUPER_SIMPLE" param.

Here is my FPV Village Video with my FPV-Raptor

ENJOY GUYS IT'S SUMMER TIME !!!!!!!!!!!!!!!!!!!!!!!!

After reading several blog posts and discussions about folk having startup issues with ESCs, APM2s, etc, I thought it prudent to build a simple servo tester to allow ESC checks sans APM functionality. The new issue of Make Magazine, #31 (I did a discussion post last week after the mailman delivered it) has a section on servos and their function. It included a common manual servo tester/driver.

I had everything needed to build it in my stash except a 50K pot  that was less than 10 turns. A quick trip to ebay and $5 later got me 5 pots.. delivered in less than 5 days!

Why, you say, didn't I just buy a premade servo tester while I was on ebay? In general I like building things rather than consuming things. If you started with my first blog posts, you may recall that I buy where it makes sense and build when it pleases me and I have the parts on hand.

In the case of my tester, I know and understand how it works. I didn't take pictures of the scope outputs because the circuit is so well known and there are much better sites that can show you servo drive theory. Go consume them for details. ;-)

How, pray tell, did I determine the CCW, CW direction of the motors without installing the props? I ran the motor at the lowest speed adjustable with tape on the outrunner section of the motor. My finger served as the direction indicator.

Motor 1 was fine CCW. All the others required a lead swap to obtain correct rotation. This process also allowed me to run each motor up to the max my simple tester provided. Listening for bearing knock, grind or other mechanical issues that might have crept into the build was also part of the process.

One thing that is for sure, we need some type of kill switch on these machines. I haven't put much thought into it but it would be a grand safety feature for these birds.

Next up I wanted to verify the output power of the ESC to the APM2. The simple tester worked so I knew it was in the range for the circuit design but the APM2 is a little more particular than a 555 circuit. On a previous trip to the local hobby shop an Electrifly Power Match power meter had followed me home.

The power meter has Rx/Tx inputs to act as a voltmeter for those supplies, perfect for what I wanted to know. The ESC may not have an adjustable output (like Castle Creastion units) but the 6 millivolt low value should not be a problem if the ESC holds steady.

The Arducopter assembly manual, if read sequentially, led me to believe that the power to the APM2 did not require the JP1 jumper. It would not power up as shown in the assembly manual. Further reading indicated that JP1 is the default mode. I tested the APM2 with a USB cable and it powered fine. Back to the PDB lead, JP1 installed and...

hurrah! Going for the gold I added the Spektrum power input. The receiver modules lit up looking for a bind (not shown in the above pic). The Tx was in the house so I declared victory and called it a day.

Little steps add up and now the ESCs are direction correct and I can begin to integrate the APM2 software and bind the Spektrum Rxs with the Tx.

Here is a short video of poshold (loiter) in strong wind.

During the last two months I was working on the RTH and poshold code for MultiWii, which is finally released some days ago with the 2.1 release. The code is mostly based on the ArduCopter RTH and loiter code, with some optimization and tailoring to fit into an atmega328 controller.

I followed the evolution of the AC code since 2.5 and the things that Jason made with the code are astonishing. I would like to say thank you for keeping AC open source which helps other projects to evolve.

And some frightening stuff

I just got my ArduPilot and put it into a Super Cub. I was running default parameters as a first test. I plotted the flight path in Google earth and did some analysis of the results. I have attached the log file as well. Based on this flight, I need to tweek the PID filters for this plane to avoid overcorrection. The offset from the road where I took off and landed might be from not waiting long enough for GPS lock. Also the takeoff and landing altitudes are above the ground.

ArduPlaneTest1.pdf

WaypointTest1.kml

The jetibox profi can display in real time 4 telemetry values. I was thinking it would be great to have some value send by the ardupilot mega 2. I spend some time to understand the new jeti EX protocol (now public by jeti: http://jetimodel.cz/data_downloads/117/jeti_telem_protokol-ex_cz.pdf) and patch arducopter 2.6. code to be able to report some data: gps, altitude, power, compass.

I connect the  ardupilot mega board to the jeti rsat using UART2:

The most useful telemetry value is the voltage of the battery, with an alarm when it goes below a value.

I also like the height to know how height is the copter. An alarm is also send when motor are armed (I am waiting from jeti to have the possibility to make my own alarm sound). Theoretically all value computed by arducopter software can be reported. I also use the old jeti protocol to be able to set different pid value from the jeti box.

A small video showing the telemetry in action:

The code (not very clean) is here: http://code.google.com/p/arduino-jeti-communication/

A previous project: http://www.diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A219277

From Matt Waite's Twitter feed:

The now mostly put together Drone Journalism Lab at @Unl_CoJMC ... as seen from a drone: