ArduCopter 2.5 released!

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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  • Nice Work Devs !!!

    But...i cant reproduce this nice Flying with my Hexa. (Flyduino)

    I see, that u all have good Videos of your Quads, but with my Hexa, it isnt so good.

    I tested the Frame / Motor / ESC Combination with other Flight Controls (MultiWii, Hooverfly, Wookong) and its working.

    So, u revistited the Hexa Code, but i cant say, that my Hexa is flying good with the new 2.5. Yeah, its flyable, but not as good as the videos of the Quads here. I did nights of PID Tuning, but it flies not good.

    In the past, we tried together to find out, whats wrong, but we havnt found a solution. I heard that some Hexa pilots have no problems, but if i see there Videos i see the same problems, that i have. They speak about stability, but it seems, that i define stability another as they.

    So, whats the solution? I tried the Arducopter and the 2.5 Code on my Quad. It flies very well. So, can it be a Code Problem?

  • Micro Quad using AC 2.5 code

    When the wind is blowing hard days and days... things like that happens at home:

    This is a micro custom quad I´ve done:

     - Structure using two wood bars covered with shrink tube to avoid vibrations; 230 mm motor to motor, 230gr weight. Propellers very  well equilibrated (a "must")

    It flyes sooo well with AC 2.5 (default PID´s !!!). See the video flying

    This extend the family of AC to the (lower) limits.



  • Hi,

    were do I find the manual compass calibration mode in MP?



  • Hi All,

    Y6 Hexa (aka Skybot)
    Arducopter v.2.5
    Default parameters
    Motors:BC-2836/7 1120kv
    Weight:1950gr + Batt.
    Size: 57cm motor to center

    Sunday evening I tested 2.5 indoors, all I can say is WOW (as many have already :-) ), using stock params STABLE was almost great except for the yaw, that tended to always come back (overcorrecting a lot), tuned it and got it better, a couple of times it would just keep turning no matter what correction I tried (1:56 to 2:20) I ended up landing.

    ALT_HOLD, did some yo-yo, but a bit of tunning got rid of it

    On the sixth or seventh flight, while doing a vertical shot from about 10m a loud BANG was heard, and it started to woble, I managed to land, and guess what, the rear bottom prop was GONE, found the pieces some 20m away!!  Well, must have been a defective prop (I thought), here's the video:

    Moday evening went for some testing outside, lots of wind some 20km/h, but quite constant. Couln't try loiter, as it would not detect my MTK GPS  :-|  (still got to investigate that)

    Tuned the yaw, and the ALT_HOLD, this has been the first tima I was able to fly some nice traslations, really responsive.

    But alas, on the third flight decided to do a high shot with the GoPro, so, I mounted the camera, and the 4S 5000mA, I first did some hovering, pointed the camera, then applied about 75%-80% thottle, and up we go. At about 30m something was heard, and saw many bits flying around!! At least two or three props broke!!!!

    It went down spining violently, it landed flat on it's back, the three alu arms are badly bent, new ones required, all 6 props gone!! no other damage.

    So concluding: 2.5 is a winner, never flown better and felt really good.
    As for my Y6 Hexa, I believe that heavy copters (+2kgr) must use better/bigger props, it flew very nice with those black 10x4.5.

    Any suggestions as what props should be used in a 2.5krg Y6 with BC-2836/7 1120kv??

    I'll rebuild the bird and try better and or bigger props.... Never trust cheap props....

    btw, has anyone else broken a prop in mid air??

    Congratulations Dev Team!

  • Hey guys, I am flying Jdrones Arducopter Hexa 880 Kv 12x4.5 props, I am using Arducopter V2.5 Hexa X. I have attached the default pid values. Is there any value that needs to be changed for my Hexa X??3691163939?profile=original

  • Hi,

    were do I find the manual compass calibration mode in MP?



  • Does anybody know if the Ch7 Auto-trim works?  I tried using it, set Ch7 to Auto-trim in MP.  Took off, got into a hover, flipped Ch7 high, hovered a bit, flipped Ch7 low, but it didn't seem to do anything.

    Am I doing it wrong?

  • Just flew 2.5 with default pids and all I can say is WAW.

    I flew in no wind conditions. I noticed allmost no drift an could keep my hands of the tx for a lot of seconds just in stable.

    AH was very good, but still had some drops, propably due to cold.

    And loiter just stayed in one place with minor drift due to gps pos shifting. I even pulleda leg for several metres and let go. Quad returned nicely to its previous postion.

    Logs are included. Pleaselook at sonar height.  

    2012-03-19 10-54 2.log

  • I got just my quad flying. I can't wait to try this. Thanks so much for your hardwork! I will post some additional feedback when I get my new props and have a chance to fly again. ;)

  • 3D Robotics

    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

This reply was deleted.


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