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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Chris this info on the MTK is highly appreciated. It is always handy to have a good point of reference. Sorry my post was a bit misleading. I have the MTK already and have used it for a while with my APM1 I was just noting I bought another when I could have waited for the improved model. At least I opted for the non Gps APM2 version and look forward to receiving this once it is back in stock.

Thanks for your answer.

I'll have a look at the wiki.

I'm using 2.5.5, hopefully it's already integrated in that version...

I just had a look at it.  When I enable super simple mode, is it active also when I'm flying very close?  Or does enabling super simple mode mean that super simple mode is activated when I'm out of range (+20m away)?

Hi Marco,

What is the specific LEA-6 chip on this prototype?

I found these GPS modules with U-blox chips: with LEA-6S with passive antenna with LEA-5H with active antenna

I want to make a try with one of these modules. Is it possible for you to make a suggestion? Do you have any idea about active and passive antenna performance? I think your prototype has a passive antenna.

I am also wondering if there is anyone having Sparkfun GPS module with U-blox LEA-5H and tried Loiter and Auto.

I have MTK GPS and obtaining S type large curves in Auto mode similar to the results of Chris. 

Marco by not soon, are we talking 6 months or more for the new GPS?

I think this two unit are compatible 100% (with correct initialization file), and costs only 40$:

The chipset is the same, the antenna dunno... :P
I can not guarantee that this gps (is for the Rabbit FC) can work with APM/12 without problems.
Remember: no warranty or assistance of the products buyed not from DIY Store...

Hi Marco, I have a Rabbit GPS and I uploaded the config file, the problem is that this GPS doesn't have a flash to store it, so it stays only in RAM wich looses configuration as soon as the battery goes flat.

I had it working with the APM and yes, it does work, however if you disconnect from power for about 30min it will loose config and resets to default 9600 nmea.

I'm pretty sure super-simple mode was in 2.5.4 at least, and maybe even before that, so 2.5.5 should be fine.

I'm not sure exactly how it reacts when close to the home location. I've only flown "normal" simple mode. Obviously when you get very close to the recorded 'home' location there's going to be some slop depending on GPS resolution, etc. and I vaguely recall another discussion that mentioned a buffer zone around 'home' to prevent freaky behavior, but I'm not sure what it actually does in that zone.

I have been getting a violent twitch on the roll of my Tricopter, it only happens when I am very slightly touching the sticks in order to hover, if I let go it doesnt happen and if I am flying it doesn`t happen? I thought it may be the dynamic gain on the Stab D parameter and have changed it several times and whilst it seems to be less violent it still happens?

In fact a few days ago it flipped several times and into the deck for no apparent reason? I was just hovering after probably ten minutes of auto mode and some hard flying. Has only flipped the once with months of the same settings and hasn`t done it since?

Any ideas would be welcome?

Hi Dean, have you log of this event?
Sometime i've little twitch with APM1/2, but only when i fly "hard and fast".

wow, for the first time, is very stable. I think more than the flight, assembly and calibrationof equipment Congratulations, I'm learning to arducopter, I have some experience flyingwith the old vti Draganfly.

Marco and Rui,what can you say about Rabbit FC,I orderd this one

for my second multirotor,will it be a problem with Y6 configuration?can you point me to latest softwere?

This could be it?

As you can see there are a few out of place pulses? I will have to get you a proper log tommorow as I lost a motor today, and on a Tricopter that means kissing the dirt..

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