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Randy's Groups

Randy's Discussions

Copter reliability vs functionality

Started this discussion. Last reply by Marco Robustini Jun 19. 204 Replies

Copter-3.3 beta testing

Started this discussion. Last reply by Thorsten 14 minutes ago. 2607 Replies

ArduCopter-3.2.1 Beta Testing

Started this discussion. Last reply by Johann Bruwer Jul 22. 585 Replies


Welcome, Randy!

Latest Activity

Thorsten replied to Randy's discussion Copter-3.3 beta testing
"Hi Wilson, if I remember correctly the RPM of the main peak reported by Mission Planner was about 8000-9000. Just hit ctrl-F and then FFT to run the analysis.  Bad vibration is detected using the VIBES log at any IMU logging rate. I assume…"
14 minutes ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"By the way, the error Flight-Mode-15 is because you're trying to switch into AutoTune from PosHold flight mode.  You can only enter AutoTune from AltHold.  We could change that, but that's how it is for now anyway."
25 minutes ago
Wilson Thong replied to Randy's discussion Copter-3.3 beta testing
"Thanks Randy for your attention and correcting me on clip0/1/2.  Ok so these crazy vibration should be indeed here. A bit confused now where does these high frequency vibration come from. Maybe my non-flex wires are to blame? Or maybe wind…"
59 minutes ago
Henri replied to Randy's discussion Copter-3.3 beta testing
"@ Erik Groeneveld : NEO-8M and RC8 lock 18 sat without problem (see the short attached bin file). Henri "
2 hours ago

Randy commented on Gary Mortimer's blog post T3 Back to the Future
"Looking good guys.  Rover seems to be the surprise with the T3 spurring on their dev and testing!"
3 hours ago
Sebastian Schürmann replied to Randy's discussion figuring out the Antenna Tracker
"Instead of the rubberband you could try to ad a counterweight for the heavy antenna. Are you using analogue or digital servos? Digital servos often have this oscillation problem, if a force tries to move them out of their commanded position. It is a…"
4 hours ago

Randy commented on Jeevan Kalanithi's blog post More gimbal news
"I'm not involved with the Solo gimbal in any way but I think 3DR delaying the gimbal until it's ready is the right choice.  A working gimbal delivered on time is of course the best outcome but the next best choice is a working gimbal…"
5 hours ago

Nathaniel Caner replied to Randy's discussion Copter-3.3 beta testing
"Randy, Thanks for the explanation. I understood about Note #1, I wasn't concerned with the number per say, it was really the fact that I got it almost immediately upon powering up while I was indoors! That seems very unlikely. Any clarification…"
5 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Thorsten rocks!  All his advice looks good to me. Some additional info: I think the higher vibes you're seeing on the raw IMU logging is indeed because there's less (or no) filtering on the results you see.  With the lower rate…"
5 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Nathaniel, The low HDOP value is because of the "Note #1" mentioned in the main part of the discussion above.  It's a bug fix to the value pulled from the Ublox (previously it was actually "PDOP"). The "Need 3D…"
5 hours ago

Randy replied to David Garcia's discussion Is Solo a good option for a developer use case? in the group 3DR SOLO
"I think if it's your first drone then getting an IRIS is a good idea because it's really very cheap ($600 from 3DR) and it's a completely proven vehicle.  The Solo is quite new and although I'm sure it's going to be…"
6 hours ago

Nathaniel Caner replied to Randy's discussion Copter-3.3 beta testing
"OK so I think I understand the answer to my primary question about the early "Fence" trigger, and it appears to have been addressed in RC8. According to the release notes for RC8 5b "fence distance calculated from home (was…"
6 hours ago
Richard Kennedy replied to Randy's discussion Copter-3.3 beta testing
"Good to know thanks Bill "
8 hours ago
Greg Covey replied to Randy's discussion figuring out the Antenna Tracker
"Yeah, I agree. It is best to start without any mechanical oscillations before PID tuning."
11 hours ago
Jakub Oller replied to Randy's discussion figuring out the Antenna Tracker
"Any oscillation in test mode suggests mechanical problems and it has nothing to do with PID's. Rubber band is a good idea, it provides an initial force that reduces looseness on the servos."
12 hours ago
Andy Piper replied to Randy's discussion Copter-3.3 beta testing
"The new default is 140, so you should set it to something like that if you are still seeing 230. 230 is now too high for true HDOP, was ok for PDOP. The 140 figure comes from Randy comparing before and after and scaling 230 appropriately, so I…"
12 hours ago

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

NAVIO+ Linux board with APM:Copter 3.3

Posted on June 3, 2015 at 12:00am 23 Comments

Click here to skip the commentary and just see the vehicle flying.

The video above shows my first attempt (which was successful) to fly APM:Copter using a Linux board (…


Multi-Vehicle testing with APM:Copter, Tracker and Mission Planner

Posted on May 3, 2015 at 8:21pm 24 Comments

For some tasks (like Search and Rescue and mapping) what you can do with one vehicle, you can probably do faster with multiple vehicles.  To test how well it works in practice I tested…


ArduCopter 3.2.1 released

Posted on February 11, 2015 at 1:00am 83 Comments

Warning: there was a period of about 12 hours after this blog was first posted where an older version (AC3.1.2) replaced AC3.2.1 for APM2.  If you think you may have downloaded for the APM2 during these initial period, please check the version on your board by looking at the title bar of the Mission Planner (see…


Steps towards S&R in Japan

Posted on December 22, 2014 at 6:30pm 8 Comments

We seem to have a lot of natural disasters here in Japan (eruptions, mud slides, earthquakes) and like everywhere else we are counting on UAVs to…


ArduCopter 3.2 Released

Posted on November 24, 2014 at 8:56pm 242 Comments

ArduCopter 3.2 (aka APM:Copter) has been released as the default version replacing AC3.1.5. This is the exact same version that we invited all users to test two weeks ago.  Users who wish continue using AC3.1.5 can find it under the "Pick…


Comment Wall (27 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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