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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Yes, everybody with serious yaw issues should try flying with the compass turned off.  Eliminate the mag as a source of the error.  That was what happened to me.  I turned it off, but the yaw problems remained, so I tracked it down to mechanical/code for Trad-heli which is what led to my yaw fix.

But if your yaw problems go away, then you know you have a mag problem.

Just curious , does the DJI wookong work out of the box ok for UAV flight? Whats the pros and cons of this system other than cost?

UAV flight is an expensive upgrade from just the DJI controller. It's circa another $2000 to buy the license and the datalink modems.

Once you've recovered from selling a kidney and bought the upgrade, the only word I can honestly use to describe it's performance is perfect. It works eerily well. My quad fly's in perfectly straight lines at whatever altitude I plug into the GCS and never misses a beat. Autotakeoff is a single mouse click as is autolanding (actually autolanding is two). Is it worth it? Only you can decide. It's no more expensive than MK when you compare the 500m limit upgrade.

2.6 is released!  All aboard on the 2.6 release discussion here!

thanks for feed back Crasher. What do you mean by 500m limit? When I look at it Ive already spent EUR6k for a couple of rigs that still aren't 100% good for UAV using the APM systems. I don't mind tinkering with them and do enjoy it, but for my friend who just wants a rig that fly's for his aerial business this DJI seems the way to go. He is fully non geek so likely easier for him to.  What are your copter specs your using for the DJI?

Hello Marco

Excellent, well done, I hope to reproduce your flights this weekend with my quad & 2.6
  I am waiting for your skills and ...... the same cap ...! ..

it is quite something to see..........

One way to improve this is to put about 30% expo in your tx for roll and pitch, this will given you tighter resolution around the centre point whilst auto-levelling.

I thought the full UAV upgrade for DJI was more like $7000?

And have they solved all their GPS problems yet?

Personally, I'd rather have a system that isn't precise, but never loses GPS lock (APM) vs. a system that is super precise, lets you fly missions far away, and then suddenly loses GPS lock and just goes into manual mode....  if you're beyond visual range, now what?

Glenn, just the move to a digital servo vs. an analog will make a HUGE difference.  The problem could simply be that your analog servo never centers, at all, really.  Every time it moves either direction, it will stop on that side of the setpoint.  

It seems that DJI has finally fixed the GPS bug:

I'm running my DJI in a nice little CX4 Droidworx frame with AXI motors. Total cost circa $4500 for everything (exc. Laptops and things) over 100 flights, only problem was me having too much fun and not seeing my Lipo alarm! Mikrokopter auto nav has a 500meter restriction which you upgrade over, but is mighty expensive, plus they charge for commercial license use.

@RL I have no idea where you got that number (traditional heli version peraps which I know is a lot more) but it's simply nowhere near that. As for GPS (im in NH not SH) mine has never missec a beat once so I really dont know how fragile this GPS problem is supposed to be. Mine boots up, locks, and flys. All GPS is pretty damn fragile as we sadly saw recently.

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