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Randy's Discussions

figuring out the Antenna Tracker

Started this discussion. Last reply by Doug Walmsley Oct 24. 41 Replies

ArduCopter-3.2 beta testing

Started this discussion. Last reply by Alex O. 1 hour ago. 2945 Replies

ArduCopter-3.1 released!

Started this discussion. Last reply by Bill Isenberger Oct 19. 1530 Replies


Welcome, Randy!

Latest Activity

Alex O. replied to Randy's discussion ArduCopter-3.2 beta testing
"I see your point. Yes it is a good way to keep the flight packs fresh. I never thought that way. What type of ground test you perform? Did they require the motors to spin? "
1 hour ago
Gustav Kuhn replied to Randy's discussion ArduCopter-3.2 beta testing
"Hi Alex, I don't want my flight batteries drained while doing essential ground based tasks, that is why I do it as above. As I said, never had problems, yet :-)"
1 hour ago
Alex O. replied to Randy's discussion ArduCopter-3.2 beta testing
"One can also plug both packs into the parallel harness and then connect the harness to the distribution board. But I also understand that in most cases it is not practical to connect the harness directly to the distribution board (ESCs). "
1 hour ago
Gustav Kuhn replied to Randy's discussion ArduCopter-3.2 beta testing
"Hi Martin, My X-UAV Talon fixed wing runs on three 3S packs in parallel. So I have this home made adapter, to be seen in my other blog posts. On initial start, I plug in a 3S small pack, just to initialize, get GPS, load/check mission, confirm…"
1 hour ago
Rana replied to Randy's discussion ArduCopter-3.2 beta testing
"Hi Randy, I have just verified, HUD is stable before and after arming. I have verified it with two APM's"
2 hours ago
Phill Simpson replied to Randy's discussion ArduCopter-3.2 beta testing
"@Andre, Good idea, I've had that problem before too but didn't realize that I was the cause of it. I'll wait to plug in the 2nd battery from now on!"
3 hours ago

leonardthall replied to Randy's discussion AC-3.1 autotune support discussion
"Hi Leonardo Bassin, It looks like you have to recalibrate your radio. You are constantly asking for a 2 degree pitch. You have not changed your dead bands on the apm so it isn't the jitter you were concerned about. So…"
3 hours ago
Andre Kotze replied to Randy's discussion ArduCopter-3.2 beta testing
"Hi Martin.  I'm guessing you're running the two packs in parallel?  If so why dont you just wait for the gyros to calibrate before you plug the 2nd battery in...?"
4 hours ago
Martin replied to Randy's discussion ArduCopter-3.2 beta testing
"Hi Randy. My copter had two flight battery packs, and I struggled to get the second plugged in and the copter still before the red-blue flashing started. Could there be a user delay parameter for that cal ? If not, could there be a warning tone if…"
4 hours ago

Randy replied to Randy's discussion ArduCopter-3.2 beta testing
"Rana, Thanks for the report. We made a small change to the gyro bias estimation code so that we reset DCM's estimate back to zero after we re-do the gyro calibration as part of the first arming.  I suspect that something is going…"
5 hours ago

Randy replied to Randy's discussion ArduCopter-3.2 beta testing
"Kev, The info is all still there but it's been renamed from MOT to RCOU (i.e. RC Out) to make it consistent with Plane."
5 hours ago
Paul Meier replied to Randy's discussion ArduCopter-3.2 beta testing
"uBlox has free software for testing and setting up of gps modules. You will need an FTDI cable."
6 hours ago
Rana replied to Randy's discussion ArduCopter-3.2 beta testing
"Randy, just tested RC14, on APM2.6, this time, quad is continuously yawing and not stopping. Set default parameters, re-calibrated the mag but same issue. F/W update to AC3.2RC14 was via mission planner.Attaching the flash log file.…"
6 hours ago
Ravi replied to Randy's discussion ArduCopter-3.2 beta testing
"@Christian, @Thomas, I had just bought a new uBlox M8N GPS receiver. i understand that baud rate and SPI has to be changed before i connect it. can u pls share how to change these settings on new M8N GPS before connecting to Pixhawk GPS port. is…"
6 hours ago
Kevin Guest replied to Randy's discussion ArduCopter-3.2 beta testing
"Hi Randy, I noticed in the Datalogs produced by v3.2(rcX) has dropped the FMT line for "MOT" (for motors). Was there a reason behind this? It was very useful for detecting how many motors were attached even when no logging was taking place…"
9 hours ago
Daniel Mueller replied to Randy's discussion ArduCopter-3.2 beta testing
"ok, its a ublox lea6h, but it was in a dome and has no documentation of the pinout, i had to reverse engineer, its possible i did not connect the correct rx wire of the module. that could explain what you describe. thank you, that was very helpful,…"
11 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

Red Balloon Finder

Posted on June 17, 2014 at 5:04am 30 Comments

As many probably know, this year's Sparkfun Autonomous Vehicle Competition (AVC) is similar to last year's except that a new challenge has…


GPS Glitch detection in AC3.1

Posted on December 14, 2013 at 6:42am 32 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 32 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…


Comment Wall (24 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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