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!


You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • Can we have some super capacitor on GPS module so it will get fix friend have the same one i think but his one locks in 5 sec.....My one on APM2 needs 2-3 minutes.....if answer is yes how do i do that and with which capacitor?


    Hello..I need help to understand what is wrong with my hexa...RCTimer3536 910Kv motors,13/6 props,sonar,APM2,3s6000MAh,3.1kg…it was flying very good and stabile last few days,alt hold,loiter…than yesterday I we received 3DRadio,433MHz two air modules one with fdti…it took me some time to manage to connect(ground air module refuse to connect if touching anything)everything seems to work well…and today on the field…hm…usually stable hexa was unrecognizable flaying around almost by itself..i recalibrated compass,gps was locked but still no help….wind was around, lets say the end I forgot my battery and had a bit harder landing,two carbon arms broken….but all the time I had feeling something is wrong…can somebody take a look at my logs and tell me?i cant tell is it bcs of 3Dradio(connected to APM2 with very,very short telemetry cable who came with it  sorry for my bad eng. i cant explain better..thanks

    2012-05-05 16-52-22.tlog

    2012-05-05 16-52-22.rlog

  • Sorry to ask an obvious question, but with 2.5.x being the first ArduCopter code release optimized for the APM 2, is the  code also fully compatible with APM 1 under the current release?  The reason I ask is I have been on an older code release for a while and want to upgrade to the most stable version.  Hopefully, I will have my APM2 soon but in the mean time any suggestions would be greatly appreciated.  Or put another way was there a GA release level reached for the APM 1 electronics prior to development focusing on APM2 moving forward?

  • Moderator

    That is my guess also, but then what is hit rad? hit radius, surely that is the same thing?

  • Moderator

    Good luck Dave, I intend to do the same, it will be interesting to see what the results are?

  • I have a question about way point radius. What do most of you use and how does it effect the transition from one way point to the next?
  • Can anybody look at this log?

    I dont know, why my Hexa is not good flying with APM1....i tried all posibble PID combinations....

  • today I wanted to try guided mode, but as soon as I added a little power: the bird flipped instantly and agressively. Any idea why? Log is attached.

    yesterday I tried it as well and the hexa tried to take off slowly. I stopped because I was running out of time, so it never completed the take-off. Today was an immediately flip.


    2012-05-02 13-21-57.rlog

    2012-05-02 13-21-57.tlog

  • hi fellas. ive got 2.5.4 on my quad. i still cant get rid of the yaw issue. meaning, i yaw and yaw locks/holds, therefore spinning around and around.

    i have done the live calibrations, spun it around my body up down left right but still yaw locks. guys i know its a really annoying question, but is there any fix for this?


  • Hello all, new guy here setting up a large hex.

    The hardware:

    • APM 1, sonar, magnetometer, GPS, v2.5.4
    • Scorpion 3026 890kv motors
    • APC 14x4.7 props
    • Scorpion Commander V2 90A speed controllers
    • six 4000mAh 3s batteries
    • motors are 34.5" center to center
    • total weight ~ 11lb

    I can't even take off.  I've tried stabilize_P from 3.5 to 5.0, all seems about the same.  flights are a few seconds before oscillations get so wild it almost flips over (would flip over if I didn't kill throttle).

    Any clues?



    2012-05-01 14-53-33.rlog

    2012-05-01 14-53-33.tlog

    2012-05-01 14-58-48.tlog

This reply was deleted.