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Randy's Groups

Randy's Discussions

ArduCopter-3.1 released!

Started this discussion. Last reply by Graham Dyer 8 hours ago. 1114 Replies

Running SITL on Windows

Started this discussion. Last reply by Randy Mar 23. 33 Replies

AC-3.1 autotune support discussion

Started this discussion. Last reply by Egert Haan 8 hours ago. 535 Replies


Welcome, Randy!

Latest Activity

Graham Dyer replied to Randy's discussion ArduCopter-3.1 released!
"No, this is with v3.1.3, using the same parameters as the APM2.5. My vibrations are low, all I changed was the APM and now I can't get Alt_Hold to alt hold so it must be a hardware difference."
8 hours ago
Egert Haan replied to Randy's discussion AC-3.1 autotune support discussion
"Hello,After finaly completing my hexacopter build and after some time familiarising myself with apm and general multirotor flying, i wanted to give autotune a try. Unfortunalty didnt go well on the first try. i'l attach video to show the…"
8 hours ago
Alex O. replied to Randy's discussion ArduCopter-3.1 released!
"If you are using a code 2.9.1b or later, the alt-hold shouldn't be fluctuating that much since starting 2.9.1b they implemented the inertial navigation. This means altitude controller isn't looking at the baro output only, it also uses…"
9 hours ago

Graham Dyer replied to Randy's discussion ArduCopter-3.1 released!
"As an experiment I replaced an APM2.5 with an old APM1.4 on my tricopter and I'm happy to say it works really well using the exact same parameters (apart from the few small APM1 specific differences). Loiter holds position very well but…"
9 hours ago
Masafumi Miwa commented on Randy's group Japan ArduCopter Group
"nob様: 三輪です。ご連絡、ありがとうございます。 英語の過去ログをよんでいたのですが、 >最初にRadio Calibration と Heli SetupのSwash Travelで最大・最少ピッチを >設定し、(これがAlt_HldやLoiterで使うピッチの範囲です)、 この部分がよくわかっていませんでした。 ありがとうございます。 後はアームして動作を確認してみます。 "
11 hours ago
Jay Galleno replied to Randy's discussion ArduCopter-3.1 released!
"Yeah that's correct. That's why the twitch on rtl still there. Be careful not to use it on windy condition."
17 hours ago
Willy Fernandez replied to Randy's discussion ArduCopter-3.1 released!
"3.1.3-rc1 is a beta firmware. 3.1.3 is an official release in MP. i think they are the same."
17 hours ago
John Campen replied to Randy's discussion ArduCopter-3.1 released!
"I cant find what the change was between 3.1.3 and 3.1.3-rc1 "
22 hours ago
nobuyuki asai commented on Randy's group Japan ArduCopter Group
"Miwa様 初めまして,nobと言います。 シングルローターヘリってトラッドヘリのことでしょうか? だとしたら、Alt_Holdモードでは、アーミングしないとコレクティブピッチは動きません。 というかAlt_Holdモードでピッチの設定はできないと思います。 最初にRadio Calibration と Heli SetupのSwash Travelで最大・最少ピッチを設定し、(これがAlt_HldやLoiterで使うピッチの範囲です)、Stabilize Col…"

Randy commented on Arthur Benemann's blog post SparkFun AVC 2014 Course Preview
"@John, @Stephen, I've got one of those pixy-cmu-cams coming actually and I'll try and squeeze in some time to try it out.  I suspect I'll end up sticking with the Odroid because it's got more flexibility (at the cost of…"
Masafumi Miwa commented on Randy's group Japan ArduCopter Group

Randy commented on Mark Williams's blog post First APM controlled aerial photography flight
"Very nice result. I'm sure most people know but there's a wiki page here which describes (at a high level) how you can do this yourself as well."
Masafumi Miwa commented on Randy's group Japan ArduCopter Group
"Arducopter3.1.3でシングルロータヘリの最調整をはじめました。 StabilzeモードとAcroモードではコレクティブピッチの設定ができたのですが、 5chをAlt_Holdにいれたところ、ロータピッチは最低位置になり、動作しなくなりました。 なにか、設定作業で気を付けることはありますでしょうか?"
Jonathan Challinger replied to Randy's discussion ArduCopter-3.1 released!
"Offsets come from magnets, compassmot comes from current draw through nearby wires. Soon we will also have soft-iron adjustment, which will correct for magnetic field distortions from nearby chunks of non-magnetic iron."

Randy replied to Patolemy's discussion Analog Signal Output through Analog Pins
"Eric,      I thought that the hal.rcout->write() command would directly take the number "10" to mean pwm output 10.  I don't think you need to worry about the physical pin number when you use that call…"

Randy replied to mark's discussion 'uBlox 6M GPS Module V2' and APM 2.5.2.....WTF!!! in the group ArduCopter User Group
"The incorrect baud rate would explain the problems including the inability to use the GPS pass-through.  If you're comfortable compiling the gps pass through sketch yourself with arduino you could replace the 38400 with 115200 in these two…"

Profile Information

About Me:
Lead developer of ArduCopter. I coordinate releases, provide support for users having trouble with their copters, add new features (most often based on ideas and suggestions from the community). I also help others get their code integrated into ArduCopter.

You can find numerous video tutorials from me here:
Please tell us a bit about your UAV interest
Interested in quads and helis mostly. I got my start in this field by reading the electronics tutorials from Sparkfun and from watching the success of Jack Crossfire's vicacopter. I've learned an enormous amount from the combined wisdom of the people on the DIYDrones forums and members of the core dev team including Jason Short, Tridge, Doug Weibel, Leonard and many more.
Karuizawa, Japan

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Randy's Blog

GPS Glitch detection in AC3.1

Posted on December 14, 2013 at 6:42am 24 Comments

AC3.1 is going out very soon and includes a new safety feature called GPS glitch detection.  There's a wiki page about it but I'd like to highlight how it works because it's near the top of the list of safety issues.  The method…


Dropping a Rover from Hexacopter - Part III

Posted on August 22, 2013 at 7:40pm 30 Comments

As a follow-up to the rover drops #1 and #2 I spent a day with Assistant Professor Nagatani-san of…


UAVs for measuring radiation levels in Japan

Posted on April 11, 2013 at 6:38pm 11 Comments

Two years after the March 11th tsunami in Japan that triggered the Nuclear disaster at the Fukushima power plant, there are still just over 300 thousand people who have not been able to return to their homes due to…


Dropping a Rover from Hexacopter - Part II

Posted on March 15, 2013 at 12:32am 14 Comments

As a follow up to an indoor test we did a about a month ago (blog post here), Assistant Professor Nagatani-san of Tohoku University, Izu-san of…


Dropping a Rover from a HexaCopter

Posted on February 11, 2013 at 8:48am 13 Comments

For those interested in using their multicopters to carry heavy objects you might be interested in the test that I performed today with Assistant Professor Nagatani-san of Tohoku university in Japan and Izu-san of…


Comment Wall (21 comments)

At 8:44am on January 5, 2011, Jack said…


I have been working on my own Quad with the NG code and have setup the Sonar and have it working very well . I have an indoor version with sonar and IR sensors and would like to know were the IR sensors are conected, what pins. I see you were working on implementing this so If you could help with basic setup I can try my hand at testing. Thanks for your work on the Sonar and good luck on the obstical avoidence.


At 5:47am on January 30, 2011, Kári Davíðsson said…

Thanks Randy. 

I do not have write access to the svn repository.

So I will send you the changed AP_ADC lib probably later today.

I am not sure if a circular buffer is needed. The beauty of a 1st order IIR filter is that we only need one "old" sample and if a second order is needed only two old samples. But I will look a little better into the filter selection before committing anything to you.

At 5:45am on August 24, 2011, Jiro Hattori said…

Hi Randy

 One of the way to introduce technology of arduino as IMU is that something like what you have done. Most of the Japanese model flyer love to fly traditional helicopter. 

 Another approach may be exhibit something very unique at MAKE fair at Tokyo Institute of Technology.  There will be many open source hardware and software freaks as well.

At 9:10pm on March 7, 2012, Ravi said…

hi randy, i had been following your forum for align450. i just got my APM2 purple. i loaded the ardu heli firmware. everythings looks to be ok on mission planner. but there is no PWM on servo out pins. i armed the APM2 and does gets armed. the radio callibration bars move proportionately. evrything seems to be OK. but in 'status' there is no PWM on channel out pins. it shows '0' PWM on all out channels. can uou please suggets what might be the reason. the APM2 works fine with arduplane and arduquad firmware. ravi

At 5:53am on March 16, 2012,


I had a different problem with my APM2 that I was able to solve by following the procedure found in the wiki with a search for APM board problems.  My board would not connect to the planner and it works now.

Good luck


At 2:18pm on May 15, 2012, wilson javier madrid sossa said…

hello hello hug.
I can help with anything, I did several plannings flight with tri and firmware 2.0.49 and flew very well.
I did a quad and install 2.5.4 program a waypoint flight and the team took off like crazy.WP PIDs are by default and does not really move as you do. can you give me some information.

I appreciate your help

At 4:41pm on May 16, 2012, wilson javier madrid sossa said…

Please can you help me. I was flying my quadcopter and hold position when you turn the team went to ground. these are the last two log. I appreciateprompt help.


At 3:54pm on September 29, 2012, Marooned said…

Hi Randy

After your changes to Optical Flow I'm having troubles with compiling the sources:

ArduCopter.cpp: In function 'void init_ardupilot()':
ArduCopter.pde:-1: error: 'SPI3' was not declared in this scope
ArduCopter.pde:-1: error: 'SPI3_SPEED_2MHZ' was not declared in this scope

I have spi3.h file include in ArduCopter.pde but somehow it's not working that way. I did fetch&rebase with original repo.

At 3:12pm on September 30, 2012, Marooned said…

Sorry for troubles. It's working now. Looks like Arduino IDE had some hiccup.

I should probably move to some better IDE as I'm using Arduino only for compiling/uploading and all files are edited in my fav editor and I have to restart Arduino every time I change something as it doesn't follow outside files changes.

Anyway, sorry for bothering you.

At 6:30pm on December 1, 2012,
William Premerlani

Hi Randy,

Regarding a question that Shyam asked about gimbal lock when he was trying to use APM to stabilize a camera, he and I finally solved the issue. Here is a link.

No one on diydrones was able to help Shyam, he finally contacted me directly.

Best regards,

Bill Premerlani

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