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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 Randy 1 hour ago. 1967 Replies

ArduCopter-3.2.1 Beta Testing

Started this discussion. Last reply by CARLOS EDUARDO BOLOGNESE on Monday. 584 Replies


Welcome, Randy!

Latest Activity

Randy replied to Randy's discussion Copter-3.3 beta testing
"Alp, That's "feed-forward".  It's probably better explained on wikipedia but it's used to reduce the reaction time in the control loops."
1 hour ago
Evgeny replied to Randy's discussion Copter-3.3 beta testing
"1. Yes, Mission Planner 2. RC not connected, I fly via joystick. Failsafe on GCS set to RTL. Yes, I пще copter back, thanks. I believe you found a problem in firmware, because AC3.3 very need for me (Storm32 support especially)."
2 hours ago
Alp ÖZDEMİR replied to Randy's discussion Copter-3.3 beta testing
"You are welcome Randy. What is the meaning of "FF" Settings? Force Feedback? :)"
4 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Alp, Ah yes, thanks for the reminder.  It's because we renamed those parameters between AC3.2.1 and AC3.3.  I'll ask MichaelO (and other GCSs to update the names on their side).  thanks!"
4 hours ago
Jakub Oller replied to Randy's discussion figuring out the Antenna Tracker
"I finally decided to make a fresh install of Ubuntu on my PC and it works like a charm. I used a tutorial for linux and make + I adopted eclipse tutorial to make it work under linux. It still doesn't work with my windows machine though. Anyway,…"
4 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Evgeny, Paul had a look at the logs and believes that the very bad vibration led to the EKF losing it's attitude estimate.  This is something we haven't seen much before.  Loss of position and velocity estimates because of…"
6 hours ago
Rick Huebner replied to Randy's discussion Copter-3.3 beta testing
"Yeah, and 3DR is still selling them for $150. Do they still have the unusable sonar? It seems to me that the sonar doesn't need to have much range as these are to help indoors, where there is no GPS reception. How far can that be, and how…"
6 hours ago
Alp ÖZDEMİR replied to Randy's discussion Copter-3.3 beta testing
"Rate Loiter and Throttle Rate settings disabled on my MP screen with rc7"
6 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Alex, From a look at the GPS messages the number of satellites is quite low - it peaks at 9 but spends a significant amount of time at 6.  I guess this is the cause of the bad position message. "
7 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Normally to work with the 3dr radio the SERIALX_BAUD rate should be set to 57 (i..e 57600 baud). It's likely that the minimOSD is not telling the pixhawk what data rates it wants.  This could happen if the minimOSD's TX line is not…"
7 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Rick, So Optical flow requires the use of a range finder and sadly the sonar on the px4flow itself isn't sufficient because it's range is very short."
7 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"An interesting discussion but to keep the AC3.3 thread more focused on finding/fixing problems maybe we should move this to a separate discussion?  It might also attract more people who are interested in analysis of this particular area who…"
8 hours ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"Paul, Ah, thank you very much for that.  As mentioned over there, I think the best idea is to try and get either the MAVLink or Serial protocols working instead of introducing a 3rd protocol to control the gimbal!  Two protocols is surely…"
8 hours ago

Randy replied to Paul Atkin's discussion Need step by step guide for Storm32 SBUS connection to PX4
"The SToRM32 wiki is here but we only officially support controlling the gimbal using the serial or MAVLink protocols.  The MAVLink protocol can only be used on Telem2 but the serial one can actually work on any ports.  The key is to set…"
8 hours ago

leonardthall replied to Randy's discussion Copter-3.3 beta testing
"Hi Rob, Can you attach a log?"
9 hours ago

Rob_Lefebvre replied to Randy's discussion Copter-3.3 beta testing
"It generally seems to fly fine, but it's not flown much yet. When I tried Alt Hold, it plummets at over 6 m/s. Luckily I had enough altitude the first time. I tried several times and have to go back to stab immediately to avoid cratering.…"
9 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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