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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Keith, do you have the .log (not the tlog) from that flight?

How do I get the ".log" file?

I haven't powered it up since the incident.

If you downloaded your tlog from the board, it should be in the same folder as the tlog was. That folder is the Mission Planner folder under logs.

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. ;)

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.  


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?


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




     What's more likely is that your THROTTLE_TRIM value was set too low.  This is the base throttle that altitude hold will use and after a factory reset this is set to 350 which seems to be too low for many people.  As you fly around in stabilize mode (and don't climb too much) it slowly adjusts this value to what your copter really needs.  So the problem went away more because you spent more time hovering around.

Marco, this is really nice but during the loiter, I can see it is still drifting a lot and I can hear the beep sound of your transmitter when you seems to give manual correction.

If things go well over the next week or two, I'll have a version that uses accelerometers to maintain loiter hold. So far the data from test flights looks great. Almost good enough to dead recon with. I'm seeing about 1.2 seconds of GPS data lag on the MTEK which is why it's impossible to tune the loiter gains too high. You'll just get oscillations.


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??

this sounds like it should be on in Stabilize mode too, Loiter will have GPS in addition

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