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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thx Norman, Your quad is lighter than mine.

I'll try to play arround with PIDs when it stops raining ;-)


So for any of you flying the latest official code, mind posting more param files and observations?  I am having difficulties with altitude hold and loiter currently with my setup.  Flying in moderate winds also is a bit hairy.  I don't consider my setup dialed in, especially since I have payload intergration development going on.  However, in a low wind enviroment, the quad is pretty stable.

Setup:  3DR quad + extended legs, 11x4.7SF props, DT750 motors, APM 2, 4000mah batt, weight ~1450g

BTW, anyone flying with Stab_I terms greater than 0?  I vaguely remember seeing advice not using the Stab_I with the PIDT1 control scheme, but I am not sure if we are currently using that control loop setup right now.


heya fellas, just out on the field and tried the new code on my hexa. running apm 1 1250, crash bang all i can say. sorry, yaw seems to be the culprit here, gets stuck again and you very quickly lose orientation. just broke 1 prop but i tried many times and done a compass recalibration too. is this yaw "stuck" issue prominent on hexa's only or throughout all configurations including quads?

I finally loaded 2.5.3 onto my 8X Quad after doing full CI erase and reset and recalibrate everything .  On some checking the sonar is not working and even if I hold it up to 2 meters it never reads more than 32cm. Any ideas why?

Also where can I find instructions how to use the compass declination calibration that's now new on MP? For now I just added my usual declination. Is this ok?

I have adjusted just the few of my PIDs to the setting I normally use.

STAB P/R 3.800  I 0.050 IMAX 40.

Any other stetting I should tweak and issues I need to be aware of?

My X8 Quad specs

Board: AMP1

GCS: MP 1.1.59

Copter Firmware: 2.5.3

Quad X8 (coaxial 2 motors/ESC per arm sharing one APM signal)

5000mAh3S 35-70C

Droidworx ADR Quad Standard, (72cmx72cm across)

Flight weight 2.4kgs

Motors 880kv Jdrones

8 Props 12x4.5

ESC 30A Jdrones

APM power supply. 5V, 3amp switching regulator (SVR3 Tahmazo)

Sonar XL-EZ0 (MB1200)

Declination:  -0.5899

John: Check your sonar wiring--it's working fine for me. Also make sure you've enabled it in the MP. Are you using APM 1 or 2?

wires all look good Chris. It does move between 20cm and 32cm so something is happening..


Is it possible the sonar was moved just a bit and it's now sensing a part of the copter? If it works a little it should work all the way out.

hey jonathan,

i followed the infomation at the top of this thread. "tuning" i did see an improvement.

Check the position of the sonar, you need to consider a very wide viewing angle, so it's likely that you're framing the gear.


Have you not seen the blog and posting that ther was a KNOWN issue with yaw stemming from magnetometer calibration?

Also check the grate on the base of the sensor, after mounting mine a little low i got a bit of mud in it after a hard landing.


Sometimes it would work fine (when the mud was to one side) and other times it would just lock and the quad would constantly climb.

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