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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  • Any features I can switch off to make 2.6 fit on a 1280 APM1 board?

  • Guys,

    So I recently started a large hexa project and am having some issues with throttle movements.  Using DYS, simonk flashed (fast PWM, better for multicopters, etc) ESCs, I cannot get any throttle response from any of my motors.  My wiring is correct, the ESCs are calibrated and correctly arm, and the motors respond when the APM is taken out of the loop and directly controlled via the RX.  I just check, and my quad with standard ESCs works normally on the same APM.  The difference being the firmware on the ESCs.

    Just a note: prior to doing the auto calibration (as described in the manual), I would get sporadic throttle response on some of the motors (never all of them).  After the calibration, the ESCs now arm correctly, but no throttle response whatsoever.

    I have seen a few of you using the flashed ESC with success. Am I missing anything here? It seems to me that there is a communication difference between the APM and flashed-ESCs.  There are many people using these ESCs successfully on other flight controllers, and I don't think the APM should be having any issue.


    6x DYS 30amp simonk flashed ESC, APM2 v2.6 delta, Avroto 2814s

    Thanks, Jonathan

  • Hi. I would like to know if there's a forum topic for ArduCopter 2.6 and if so, if you could post the link at the opening notes, would be great.

    Today I made my first auto flight with 2.6 Delta. It was a flight of about 550mts with medium wind (20 - 30km/h) Very pleased with the results taking into account the wind. Loiter in wind behaved resonablly but I need further tunning. There was just one small detail. At the last checkpoint, the quad did try to land and did not respect the Auto Approach 5mts I have defined. I will report, but if anyone is using Auto Approach and test an auto flight with same result I would appreciate comments. One of the pictures in angle so you can see there's not a great deviation in alt even tough I'm only using baro and APM 1.





    The best thing I've been noticing is it's incredible reliability. So far no "strange" behaviours. Great work everybody.


  • Hi again all, I've just loaded 2.6 onto my new quad, and wow! As mentioned earlier the stability tweak of Jason has made a huge differnce. I took her outside and having never flown acro before was able to do loops! I then flew stab mode and also did over 100 flips!! Just pump the throttle, and as you turn hard righ/left/forwrd/back just cut the power, she flips and then you touch the trhottle and motors kick back in 'catching' the quad out of the air, VERY VERY stable! Will shoot a video of this tomorrow and can't wait to try this on my big octo ;)

  • Moderator

    To follow up testing of 2.6 Delta, Keeping the same PID`s as were posted yesterday...

    Here is a KMZ file showing two identical missions in auto mode, they were started in different locations, as you can see, but from the first waypoint onwards, I think it speaks for itself?


    I still haven`t managed to get logs working though? still only logging GPS and ATT..

  • For those who tried to upload 2.6 delta by getting latest source from GIT, please empty your local copy first.

    Yesterday I tried by getting latest and upload, and I got problem connecting to Mission Planner and also had some issue with DataFlash. So I clear my local copy of the codes and get latest. Upload to my APM2 and everything works well.





  • I am trying to load 2.6 Delta via arduino, I keep getting "AP_Intl 6 does not name a type" when I try to upload or verify, what am I flagging wrong? I cleared // from # define CONFIG_APM_HARDWARE APM_HARDWARE_APM2 but still get this error for .6 delta verison,  1260 is selected under board type and right port is selected...


    BTW how can you search a specific forum like this one? most have search tools, but this forum I can't find a search...


  • Any idea when 2.6 will be pushed to mp?
  • Moderator

    O.K a bit of a long post.. But I managed to get out and do some filming today of 2.6 Delta, as I said before the Loiter I cant seem to get it as good as with 2.5.5 but the auto mode and rtl I have seen improvement and also in stability. I have also flown with Acro and am pleased with that also... I have adjusted alot of the PID`s to get to this stage, and am sure I wont get it any better? Still the yaw is not very responsive even after adjusting the PID`s for it, but I can live with it, as I dont do alot of hard flying most of the time?

    Right so first up will be the Loiter and Auto with 2.6 and then after with 2.5.5

  • I finally had success working all the bug out of my Y6 today, butrned through 3 batteries no problems, just a small bit of wobble, but I had a loose connection on my channel 6 so my tuning was no use in the field...  I started messing with channels in MP and in remote.  I found the loose channel 6 connection, but somehow I messed up the PIDs beyond repair in the process..


    I messed up my PIDs somehow, I accidently placed ch 6 on the wrong tuning set, and I cant get back to stock setting.  I reloaded firmware but now it won't eveb bench test. What is easiest way to get back to default PIDS...  Can someone point me to a default param or post afile for y6? please?


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