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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Yup, 'Big Up' to all you developers and testers, I am having a ball with this 2.5!!

Thank you very much indeed!!

Marco....OK, I'll BITE!!

250g battery hanging off one leg,

DJI flamewheel (glued), standard ardu 850 kit, 10*4.5, 2200mah

Stab mode only - quite a lot of it hands free :D

Arducopter 2.5 Battery dangle from Kamakaze UK on Vimeo.

Thanks for the new release guys! Can't wait try it out.

Is the norm to save flight stuff once you disarm? Quite often I fly till the battery is low, land and unplug while armed. I would nit see the thebenifit then.

Would it be considered bad practice to do this and should always disarm before unplugging the battery?

Hi Guys

Well just loaded 2.5 and had quick test flight in the last fading light of day, and on the last fading power in my battery - and can only say WOW. The difference is obvious. I am flying an APM2 Quad, 3DR frame 880 KV motors 12 x 45 props. Rate Roll/Pitch P at 0.095 and Throttle rate  0.35 as on previous version. 

Very new to this, only completed quad last week and this is my first R/C flying too, and would just like to add that I am very happy with APM2 in general. Despite my inexperience I have not yet broken a prop or anything else and the Quad has been pretty much flyable from completion. I have a drift issue but I believe it's a leveling / vibration issue and not due to the controller. This version will make it much easier to sort out I'm sure. 



That's right Boris; it won't fit unless you compile with Arduino and disable CLI. I've got Issue 392 open for the ability to set your GPS module definition (example:, which should let us specify our GPS and save some space by not having all the GPS drivers loaded for the Auto Detect. I'd prefer to do that over killing CLI...

Randy- Can you add this to page 1 to let users know? 

"- think i got it on video though ;)"

Makes it all worth while, doesn't it?   ;)  Hopefully you caught your reaction on video too! :D

Tried out onboard video with v2.5 after having sorted out vibration insulation problems for the camera.

My setting is here, i've real X8 with independent channels for each esc! :-)
10 flight today with my heavy X8, no issues (or subtle, already reported on the dev list)! :-)
This is a milestone release! :P
Yes John, i've tested all, and work fine, but need a careful tuning of pid!


About yaw issue you may have interference with the compass.
happened to me during the 2.5 alpha testing, I solved it by removing the compass from the OilPAN (APM1) and moving it out off the board, under a thin sheet of aluminum.
As soon as I can I take a picture and post here.
With APM2 course you can not move, then you should check first if the compass has that problem is very simple: try to fix your quad to the ground so that with the throttle almost to the maximum does not move, look at the red line on the planner, when you turn the throttle up (over 60/70%) the red line does not have to move.

What's the problem Todd?
Please explain me better, thanks!
First try to put STAB_D to 0 and write here your Rate_D value... tell me if it improves.
I've the same wobbling with my X8, removed with STAB_D = 0, i use only an high "RATE_D" (0.008).


Use More Beer!!! Always a good motto! from Kamakaze UK on Vimeo.

Yes I know.....

Just crashed my large Tri-Copter....AMP2...2.5..

In Stab... Flying forward... Pulled back hard and the Tri went noze up 90 deg...  This has happend before many months ago and many versions ago... though it was gone... 

Loiter did not work so well either... Alt hold (baro) is really good ... plus or minus a few feet...

In the Graph below I am faily sure these lines shoud not diverge !!


lolololol Dave, you're too much ! Let's not consider the 2nd part of the video :D That was great, next time, drink only half can :D


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