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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Very Smooth Loiter....Wow!!!

Yes Adam, he returned in the exact position, but i've in one hand the tx and in the other the phone... :P

good point :-)

are you on Sonar? I am pretty sure that I could get that if I activate it.... as the baro will not have so much impact anymore... 

Yes Dany, sonar enable! I tried only with baro, there's no difference in position, only the "yo-yo" effect but much smoother... :-)

cool, and no yo-yo at higher altitude when you get out of the sonar range? 

Of course, but much smoother! Tomorrow I will do another video with sonar disabled.


I have just uploaded 2.5 and am flying a quad with 850's, Standard 20 A ESCs, APM1 with Sonar and GPS.  What do you recommend for PID settings to ensure a steady ALT Hold and a reliable RTL?



just take the config files attached on page 13 with Marco video! 

Hi Allen, try with my parameters (inside the zip in the "loiter post").

Thanks to everyone for the flight reports and logs, which are very helpful. Going from private beta testing to public release increases the number of test flights by orders of magnitude, which has been great in catching a few edge cases that hadn't come up in the dev team testing and sim process. Most of these are pretty simple one-line bug fixes, and Randy, Jason, Tridge and others on the team have already fixed most of them for what will be the next maintenance release, 2.5.1. It's in the Git repository now, but if you don't want to use Git you can load the code from the downloads section here

Fixes include catching an unititiated variable that caused Loiter to zip off in some direction at first use under some conditions, some default gain adjustments, a fix that won't let you enter way out of range parameters in the Mission Planner, and a bunch of others you can see here

Great one Chris and dev team!  

this will make things really smooth now.   Cant wait to load it and test.  

And ETA for the Mission Planner push update? 

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