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 rough estimate on when 2.6 will be ready (1 week, 1 month, 6 months, next year) ?

  • Haven't heard much about the Optical Flow sensor.

    Is it now fully supported or still experimental? (I see that it will now work on APM2)


    Anyone have video of it in action?  maybe in some windy conditions.


    Also can it still be used with the Sonar?  or recommended one or the other.


  • Guys,  thought I would post this hear as well, since this thread gets more visibility from the right people :)

    In sum,  my GPS no longer gets a fix.  I consistently get 5-7 sats and let it sit for a longgg time and no fix.  CLI GPS test gives no lat, long but it does give alt and sat count.  I am running an APM 2 with 2.5.5.  The GPS used to work, the proof being that I had many loiter flights under my belt.  I am not sure what has changed to cause this, but I am thinking it is hardware.

    Is there a GPS hardware "reset" that I can try?  Or any other suggestions?  Everything else seems to work fine on the board.  Should I try a different GPS?

  • Awesome, cant wait to get my quad up in the air again!

    Loiter worked reasonably well for me even in strong gusty wind. did a better job at holding position than i could!

  • Whats going to be new in 2.6?

  • Moderator

    O.k Marco here is Loiter Mediatek style with wooden frame and cable tie Tricopter :)

  • Developer

    Simple mode with ArduCopter:

    in this video i play a lot with "Simple Mode" for testing yaw/compass precision... :-)
    I never use the SuperSimple mode, i don't like it, and if something is wrong with the gps can go wrong during hard maneuvers.

    Bests, Marco

  • I've just filed an enhancement for simple mode.

    Hopefully the developers can make super simple mode available at all times, not only when the copter is more than 20m away.

    I think super simple mode is the only way to really save your multicopter when losing orientation and thus control.

  • Hi

    Yesterday 6 min in air ended with a crash: 

    The day before yesterday the Planner button  LEVEL was used for calibration. Back home with the hexacopter on the kitchen table:


    I suspect this is the explanation for the fast left-down action by the program 2.5.5.

    In order to finish a so far successful flight I switched from ALT HOLD to STABILIZE. Next moment the crash. I have asked before: When can LEVEL change without the Planner?



  • Moderator

    Using the USB when changing batteries is a good idea if you have the laptop with you the whole time? and in my case the usb port on my apm2 is very sensitive, if you move anything it disconnects. What I ended up doing which gives more than 15 minutes of time without plugging the main battery in.3692431899?profile=original

    Just a microswitch, diode and a single cell lipo. Plugged into the output rail. You can turn it on before flying so the gps gets time to lock or just between battery changes, and if you forget the diode stops the 5v getting to the cell. Just switch it on or off as required.. Simples


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Aug 25