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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 minute ago. 3253 Replies

ArduCopter-3.2.1 Beta Testing

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


Welcome, Randy!

Latest Activity

Randy replied to Randy's discussion Copter-3.3 beta testing
"Wilson, Sorry, I actually downloaded your log when you first posted but didn't complete the analysis. I think the lean is caused by the poor GPS location.  The NSat is really very low at only 5 or 6.  I think the GPS position was…"
1 minute ago

Randy replied to Randy's discussion Copter-3.3 beta testing
"There are a number of parameters listed on the RTL flight mode wiki page that may help.  So for example, if you don't want the vehicle to descend and land as part of RTL you can set RTL_ALT_FINAL to a number > 0.  like 10m and…"
1 hour ago
fillycheezstake replied to Randy's discussion Copter-3.3 beta testing
"I've tested it - none of the rc channel control code was changed. I can confirm all serial mode features work. I haven't tested the gimbal in mavlink mode.  This is with firmware .86e & 3.3rc10. Make sure you set the gimbal mode…"
3 hours ago
Alex Buckley commented on Randy's blog post ADNS3080 Optical flow sensor now available in the DIYDrones store!
"Well they don't call it DIY for nothing eh?!"
3 hours ago
Craig replied to Randy's discussion Copter-3.3 beta testing
"I have a dumb question.  I finished the 3.1.5 and 3.2.1 on the 1st hawk lite today but now I am going to do the 3.3-rc10 but I need a howto on the auto tune for 3.3. On 3.1.5 AT took just a few minutes so I was able to complete on a single…"
5 hours ago
Richard Kennedy replied to Randy's discussion Copter-3.3 beta testing
"Another aspect that should be considered as far as the reserve you set is the altitude you usually fly AND check the max decent rate. If the MR goes into FS and tries to land itself it can literally run out of juice just coming down so darn slow. I…"
6 hours ago
Ted P replied to Randy's discussion figuring out the Antenna Tracker
"Is anyone running the tracker via a small computer like BeagleBone or RPi? I'm trying to get MAVProxy working on my Beaglebone, and have done so successfully, however the tracker module will not show up when doing a "module…"
6 hours ago
Brad replied to Randy's discussion Copter-3.3 beta testing
"Isn't the WPNAV_RADIUS parameter expected to be used for exactly this purpose?  To avoid wasting time hunting for an exact position?  I assume that's why it used to be the cut-off between the two behaviors.  The problem was…"
7 hours ago
Luis Vale Gonçalves replied to Randy's discussion Copter-3.3 beta testing
"Hi Brad, I was discussing this issue of the radius with Randy, and the 2m seems somewhat "short" because of the errors associated with positioning,  read "GPS positioning radius", which would result in never being…"
8 hours ago
Wilson Thong replied to Randy's discussion Copter-3.3 beta testing
"Though a bit off-topic but I can share some data on my LiPo testing. I think there are 2 issues mixed together: 1) LiPo "mAh" can be over-rated. The steep descent of LiPo terminal voltage may happen earlier than expected.  2)…"
9 hours ago
Trent Russell replied to Randy's discussion Copter-3.3 beta testing
"I agree with this completely.  As a matter of fact, this change may ground me until there's a workaround.  I've had two hardware failures in recent memory that resulted in radio failsafe RTL over water.  If i'm…"
9 hours ago
Brad replied to Randy's discussion Copter-3.3 beta testing
"Randy, I have a concern about the rc10 change mentioned in item 3e of your updated OP.  5 meters seems high for a fixed value.  I frequently launch from my back yard where I have trees, shrubs, and house on 4 sides with a 5 or 6 meter…"
9 hours ago
Wilson Thong replied to Randy's discussion Copter-3.3 beta testing
"Thanks Trent for looking into my log. That's my problem RC2 at max but no RCout response. Around the moment after flight-mode = LAND (the green box in the plot below) : - ThrOut = 65% - RCOUT does not clip at max - pitch follows nicely the…"
10 hours ago
MarkM replied to Randy's discussion Copter-3.3 beta testing
"Can you give me a link to a lipo manufacturer that confirms that? The only one on-line that I could find in a rush, bottom of the page item number 5 clearly says that it is the 80%…"
10 hours ago
Trent Russell replied to Randy's discussion Copter-3.3 beta testing
"I'm not sure i understand what i'm seeing.  There's a maxxed out RC2 input, but ( i see as wilson mentions above) pitch follows despitch through the maxxed RC2 event, with no RCout response apparent on motors 1 and 3.  "
10 hours ago
Wilson Thong replied to Randy's discussion Copter-3.3 beta testing
"What really strange to me is that "pitch" actually follows nicely with the "desPitch" as you can see from the plot. It is the "desPitch" diverges from the "RC2" input. Why this can happen? Doesn't…"
10 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 33 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 (28 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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