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Randy's Groups

Randy's Discussions

PixRacer with Ardupilot

Started this discussion. Last reply by Jared Muirhead yesterday. 1092 Replies

Ardupilot on QC Snapdragon

Started this discussion. Last reply by SANGYUN HWANG Jun 2. 6 Replies

Pixhawk 1MB flash limit

Started this discussion. Last reply by Mark Brummett May 11. 85 Replies


Welcome, Randy!

Latest Activity

Cala replied to Randy's discussion AC-3.1 autotune support discussion
"Yes, you can do one axe at a time: Roll, change batt, pitch, change batt, and yaw, you have to go to full param list and change autotune all three axes for roll axe, then pitch alone and last yaw alone, looks…"
5 hours ago
Jim White replied to Randy's discussion AC-3.1 autotune support discussion
"I hope I'm posting this in the right place. I rebuilt my 2013 3DR quad this week and am trying to get it back into service.  It is now all running OK so I attempted auto tune today.  It flies OK but is a bit twitchy in loiter in a…"
7 hours ago
OlliW commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"Very cool stuff !!! I totally missed that it's possible to have MP showing the heading lines (or whatever they are called correctly) for two units. How is that done? I mean, I would very much like to have that also for a gimbal attached to a…"
13 hours ago
Simon Wunderlin commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"@Randy: thank you for the update on hardware compatibility, I guess a PXFMINI+RpiZero would be a small and flexible solution. Do you have any infos on how to mod that wifi dongle ? @lianpinkoh: thanks"
13 hours ago
Monroe King commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"The only other thing I would be interested in seeing would be the capability to hand off from one tracking station to another. Lol I know I'm asking too much. Great work Randy and Stefan and others working on the tracker. It's just…"
15 hours ago
Monroe King commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"Wow that is really good news for some of the stuff I do. It also seems the prediction portion of the software has made a great deal of progress since I last tried the tracker! Do you think you had the slew rate optimized for the prediction I noticed…"
16 hours ago

Randy commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"@Monroe, Yes, although I haven't tried that I think it will work fine.  In the latest set of changes we changed the tracker's position updates to come from the EKF (previously they were coming directly from the GPS).  This should…"
16 hours ago
Sebastian Schürmann replied to Randy's discussion figuring out the Antenna Tracker
"Hi Randy, I just finished building my new RPi3/Navio+/Wifi based tracker. I would like to test it with a SITL vehicle, via the Mavlink mirror feature in MP. I build antennatracker from sources yesterday morning, but  I have no problem…"
17 hours ago
Monroe King commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"Randy can the tracker be mobile now? In other words can you mount the tracker on a vehicle and follow without loosing tracker lock?"
17 hours ago
Ravi commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"I think it is a great idea to use RPi for tracker. using RPi for telemetry is a very cost effective solutions since the wifi dongles are available for under $10. eventually video will also zero down to RPi. so all three integrated into the same…"

Randy commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"@Simon, Thanks!  I'm afraid though that these later versions only run on the higher end hardware (Pixhawk or faster).  For me it's tough to prioritise back porting the changes to the older branches with so much else going…"
lianpinkoh commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"@Simon, here are the instructions for both pixhawk and APM2:"
Jared Muirhead replied to Randy's discussion PixRacer with Ardupilot
"I am having an issue on the pixracer board.  I am using the PX4_PWM rangefinder.  It works fine, and CH5 on the board reads the correct distance.  However, enabling this rangefinder kills the output on CH6.  I'm no longer…"

Hugues commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"Great improvement over the previous tracker 0.76 release. Do you have 360 movement on both axis with the PT785 ?"
Rana commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"Excellent !"
Dusan commented on Randy's blog post AntennaTracker v1.0 on NAVIO2 with Bebop2
"For the price of PT785 servo city pan/tilt setup, one can build heavy duty tracker that can carry  far heavier antenna setup. Guys at satNOGS have developed nice tracker, V3 is using DC motors with encoder feedback, which…"

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

AntennaTracker v1.0 on NAVIO2 with Bebop2

Posted on July 28, 2016 at 2:07am 18 Comments

ArduPilot's Antenna Tracker firmware has been making some quiet progress over the past few months.  They're all documented in the …


Copter-3.4 beta testing starts

Posted on May 30, 2016 at 10:30pm 22 Comments

Copter-3.4-rc1 has been released for beta testing and can be downloaded using the Mission Planner's Install Firmware screen's beta firmware link.  Some of the changes since Copter-3.3.3 are listed below.

1) EKF2 allows "boat mode" (attitude initialisation without gyro calibration)

2) …


Terrain Following Missions using Lidar

Posted on May 13, 2016 at 11:30pm 24 Comments

The upcoming Copter-3.4 release will include terrain following support for mission commands using either Google earth altitude data or a Laser Range Finder.  This is a demonstration video shot at a ski hill near my home in Karuizawa Japan of this new feature.

For this test I used a venerable 3DR IRIS with a …


Copter-3.3 released!

Posted on October 8, 2015 at 9:58pm 84 Comments

After months of testing by the beta-testing team and no significant issue during the soft release, Copter-3.3 has been released.  You can load this version onto your vehicle using the…


Copter-3.3 ready for wider use

Posted on September 28, 2015 at 7:18pm 82 Comments

After months of testing by the beta-testing team, Copter-3.3 is ready for wider use.  Similar to the Copter-3.2 release this is a "soft launch" meaning that for the next couple of weeks, we are asking users to load the new version using the Mission Planner's "Beta firmwares" link…


Comment Wall (32 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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