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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  • Developer

    ArduCopter V2.6ß - Video of all the automatic function (APM2 - 3DR U-Blox LEA-6H GPS prototype):

    Hi all!
    The team is working hard to offer you an experience of flying stable and functional.
    This video demonstrates the reliability of all the automatic functions with the new code, using APM2 and the new "3DR U-Blox LEA-6H GPS" prototype, soon be available on the market.
    The excellent accuracy of this gps unit, combined with a good debugging of the code, offers a tangible improvement of all the automatic features, including the new "AutoApproach", available soon on the planner in the upcoming 2.6, which will be released when we are 100% sure this all works out constantly.
    In this video my new "APM2 Kamikaze Quad" (frame by Alessandro Parisi), Emax GT 2215/12 motors, 10x4.5 nylon+carbon props and cheap RC-Timer esc (30A, 10$) reflashed with "SimonK" firmware.

    Stay tuned!

    -= Marco =-
    (AC Dev Team)


    Home-made + hexacopter, 1.8 kg + 3700 lipo
    APM2 2.5.5 as downloaded by Planner
    jDrones AC2836-358 880 Kv motors
    jDrones 30 Amp ESCs
    12x45 propellers
    Graupner mx-20

    I don´t dare to launch so I keep the hex close to ground. Too close?
    I am still too unexperienced to fly this bronco. COULD PARAMETER ADJUSTMENTS MAKE IT EASIER FOR ME or should I stick to the simulator another month?


  • Thanks Dave I just didnt know what I was aiming for.


    Regards Pete

  • Sad story. It seems to be that the APM1 128k is no longer supported. Mission planner is telling me that I should upgrade :(
  • Hi Guys can someone tell me what effect a too high Rate P value has (Mainly how do you know when it is too high).

    Too low and my hexa is all over the place but from 0.19 to 0.21 seems much stable, but how do you know when you have gone too far.


    Regards Pete

  • Regarding Thottle glitch issue, I just made a flight test and encounter a glitch again. When I look at my log, I'm quite surprise with the Thr In graph of CTUN log. The thorttle is shown a glitch.

    Also I analyse Roll IN of ATT log, there is 1 value on row 4747 and the value is very high 32610.

    Is this alrigh?

    I was also reporting what I feel an issue with this APM2 board that I have on another thread. The board that I have now (my second board), the Tx & Rx led (Orange) will flicker very fast when I turn on my TX.

    Do you guys think this issue and my thortle glitch related? I'm suspecting the ATMEGA8U2 that responsible to decode RC signal is too busy with the serial TX & RX and causing the RC decoding functionality not working properly.

  • Developer

    Great.  As Mentioned on the MPU6000 scaling issue thread, I've just pushed 2.5.5 out to the mission planner and it's also available in the downloads area.


    Now, back to working on 2.6...

  • Developer

    ArduCopter V2.5.5ß on the download area:

    A patch release which has the following improvements over 2.5.4:

    1. MPU600 accelerometer scaling fix (affected 3dr APM2s shipped from early May)
    2. "Retro Loiter" by Adam Rivera (uses ground speed directly from GPS instead of calculating from lon/lat position)
    3. "AutoApproach" function by Marco Robustini, developed by Adam Rivera

    No other improvements to flight dynamics and auto function such Loiter/RTL/Auto in this release.

    Bests, Marco

  • 2.5.4 for Y6 ?


    I am upgrading from a quad to a Y6 but there is no 2.5.4 firmware. What’s the deal with Y6 support?






  • I have a problem with CH6 Tuning.

    I would like to use my CH6 for tuning Rate Roll/Pitch.

    What option do I have to select?  I've selected CH6_RATE_KP for the moment and set a min/max value of 0.8/0.14.

    The only problem is that CH6 isn't changing any of the values in MP.  The only things that I do see is that every time I connect my APM the basic value for Rate Roll/Pitch have been reset to 0.000.

    When I don't assign CH6 for tuning, no problem, values stay intact.


    What am I doing wrong?

This reply was deleted.


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Aug 25