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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This is a great release and the Dev/Testing team did a great job! This version is a pleasure to fly and it's the most stable yet.


Woohoo.. great job devs!  I can attest that this version (well.. GIT as of yesterday) is much much improved.  Looking forward to testing it out some more

Great News ! Congrats !

Is the hexa patch supposed to also fix the dreaded lately found flipbug because of DCM problem ? (problem that i don't understand of course but Marco kept refering to in the 2.4 release thread )

Also really good idea to give PID advices from start for this version

APM 1.4 users can still run? , and the 490mhz esc freq should work for everyone or should one take precautions about that?

I can't wait to try this! Awesome job everyone :)

Congrats to the whole team! There was a huge amount of testing on this one, with some real breakthrough work by Tridge on optimizing the DCM. 

The APM 2 should now significantly outperform APM 1, as you would expect due to its superior sensors. We just hadn't updated the code for its digital sensors until this version, so this is the first version of the code that really shows it off properly. 

We'll be releasing  version 2.3 of ArduPlane in the next day or so, which uses the same updated DCM libraries. You should see significant performance improvements with that, too. 


I'm ready to go now.....I've be waiting on this very cool update to put my new

hexa up for the first time with it's new reasoning abilities !!!

After watching the vid ... I am glad I waited .


Yipee !!!


Thanks so much to All for getting IT done !!!





Thank you to all involved, great job! We had to wait a while but it's now here.

Just had a test flight in the garden with the official v2.5 on APM2 (although I did fly 40 minutes yesterday with a recent git version) and all is good, I did not have a leaning incident which has been something that has been plaguing my quad. It's a X525 frame with KDA20-20L motors, HK SS 25A ESC's, 3 or 5 Ah 3S batteries, 11x4.7 APC SF props, weight 1.3kg. Default params.

Looking forward to more trouble-free flights

Fantastic!!! Thanks for all the hard work guys. Now though I'm wondering should I wait for a week or so and see what the general feed back is, and stick with the natural 2.4.1 ?? Or just load and try..hmmm.. thinking thinking ..

John...Jump! :)

hmmnn...something I've just noticed after another quick flight, when I switch to ALT_HOLD (was done at 2m high) the quad drops like a stone! On the ground and still in ALT_HOLD it won't take off until the throttle stick is almost at full? Normal hover for me is about 55% stick travel.

log attached


ready and loaded in the morning quad large field test apm 1, 10x4.5, lv EZ4, frame and engine 650v2 XAircraft, 10amp esc, 1350 kg, 900xbee, bat 2650,
thank you all.

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