Version 2.5 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area!



  1. The first ArduCopter code release optimized for the APM 2.  Leans and drift should be much reduced or even eliminated for most users.  This was accomplished through a number of core improvements to the DCM implementation by Tridge like this one and this one.
  2. Loiter and waypoint following should be improved due to a D term bug fix, some tuning and the improved DCM performance mentioned above.
  3. On start-up, the yaw heading is updated with first successful mag read (so you should no longer see the slow rotation from north to your actual heading).
  4. Increased output rate to ESCs to 490hz.  This update rate is also user selectable using the new RC_SPEED parameter.
  5. hexa copter stability patch bug fix (should resolve slight flattening when pitching forward and accelerating very rapidly).
  6. improved baro filtering
  7. fix to dataflash logging of Mag heading
  8. addition of H1 swash plate type and bug fix for proactive yaw compensation for collective pitch changes for TradHelis.



The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P in 25% steps.

While some testers have reported very good flights with the default PIDs, some have reported that this release is a little "sharper" due to the DCM improvements and have found they needed to:

     reduce stabilize P by 10% (i.e. 4.5 -> 4.2)

     reduce stabilize D by 30% (i.e. 0.15 -> 0.10)

     increase rate D from 0 to 0.001

Tuning loiter can be tricky.  Refer to the discussions which will appear below for more community feedback on what parameters work best.


Please post your feedback in this discussion.  For enhancement requests  and bug report, please add them to the arducopter issues list.  When possible please include logs (tlog and/or dataflash) and tell us whether you're using APM1 or APM2 and what version of the software you're using (presumably 2.5 but tell us anyway!).


Thanks for this release go to the developers (both in the core team but also those who have provided bug fixes through the issues list) and also the community members who participated in the previous release thread and provided some great detailed information in the form of issue reports and logs which allowed us to nail some bugs!


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Kevin: Are you using 2.5.3?

Caption for the above: "Electric multicopter takes its pet airplane for a walk."  Or is that a fly?

On my standard quad, APM1, 1280 board, 2.5.3, stab is as good as always, alt-hold worked very well, even in gusty conditions.

Area too small for any other tests, but so far so good, thanks team!

Hi Marco. I have been flying since the early days and just upgraded my APM1 1280 board to a APM2 and put 2.5 on it. Simple mode used to work great for me, always maintaining forward as the initial direction. With the APM2 I find that it works fine sometimes, but other times it seems to forget the start direction entirely, and suddenly control forward is quad forward. Any suggestions on how to fix this would be appreciated. I attached some recent logs.


Hi Folks,

had a crash yesterday.

My Octo tilted to one side and came down like a stone.

Flying in stable mode.

Tried to read the logs,but i´m kind of not able to.

So here´s a little video and the log,perhaps someone can help.

How do i upload the log file ?

APM 1 2560


Octo X



Youtube says:

This video is private.
Sorry about that.

I have flown almost every version since NG and I knew in a millisecond 2.5x was a major leap ahead. I have a x525 quad, apm2


and the instant I took off with 2.53 I knew it was great.  All of us who fly copters know ground effect and the need to pop up a couple of feet to get stable. This software can float the quad an inch high with no ground effect!  Absolutely the smoothest thing ever.

Dave C is right - tuning is now like it should be, no longer change .001 and it is unflyable. I have used many of Marco's pids - the rate / stab tweaks really make it nice and responsive - I almost feel like I can fly like Marco! (HaHa - I have a looong way to go).  The Loiter P from .35 to .1 helps, maybe 3 meter in low wind now,

The one thing I had that diverged from Marco was Altitude Hold P and I.   Where he went down from .5 D to .2,  I went to D = 1.3 and I = .01 and both sonar and baro seem very accurate and responsive. I just guessed here, it would be interesting to see what others get. The defaults were kind of soft and sloppy, maybe I should play with throttle too. The APM2 baro is amazing -usually hangs within a few inches, sometimes will move a foot or two and then recover stability.

Another note, I agree with others - I was using cheap flimsy props, finally wen to APC and It flies and sounds much better. The almost never snap at the hub like cheapies, yaw and control is much better.

Anyway, I am now anxious to go on to mission functions.  It is impossible to thank Jason, Tridge, and all the other geniuses behind this. We also need to thank Marco, JLN, DaveC for thier brave testing and feedback that helped me many times.



Try again , Jan

And here´s the log file


Can someone post their Loiter Numbers along with Nav numbers...

Along with any info on how to tune Loiter..

WIth Loiter_P at 3.0 my tri drifted off by 400 feet measured... but it did stayed at 10 feet +- 2 feet !!!


Eddie Weeks

I write this yestarday.... i'm sorry Paul...

Hi Fred, i'm sorry for your crash, which version of ArduCopter? 2.5 or 2.5.3? APM1 or 2?
Please open a issue here, describe the problem and upload your log, thanks...

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