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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I have used the 12x4.5 from ebay, which recently has just exploded in flight. Lousy quality I guess, so I went to buy APC props. Although a bit more expensive  seems to be much more solid. The ebay ones seems to be crap. I tried to bend an ebay prop, and it took little force to break at the hub. APC seems much stronger. you get what you pay.

I buy all my props here and haven't had a single problem. Plastic ones are very soft but indestructible - great for begginers. They mostly bend. I had them break only when hitting the ground upside down hard.

Carbon reinforced are way better, i fly 8" all the time (and they are close in performance to 9" plastic ones) and they also don't break that easily, they usually survive a handful of crashes.

And I never had to balance any of them - nothing to balance here :-)

Fully agree. I also use Flyduino props 10" and 8" and all are great. Never needed to balance.


Nice Work Devs !!!

But...i cant reproduce this nice Flying with my Hexa. (Flyduino)

I see, that u all have good Videos of your Quads, but with my Hexa, it isnt so good.

I tested the Frame / Motor / ESC Combination with other Flight Controls (MultiWii, Hooverfly, Wookong) and its working.

So, u revistited the Hexa Code, but i cant say, that my Hexa is flying good with the new 2.5. Yeah, its flyable, but not as good as the videos of the Quads here. I did nights of PID Tuning, but it flies not good.

In the past, we tried together to find out, whats wrong, but we havnt found a solution. I heard that some Hexa pilots have no problems, but if i see there Videos i see the same problems, that i have. They speak about stability, but it seems, that i define stability another as they.

So, whats the solution? I tried the Arducopter and the 2.5 Code on my Quad. It flies very well. So, can it be a Code Problem?

I also have FlyduSpider and wasn't able to tune it with 2.5.  What are the problems you're having? Mine yaws randomly, goes crazy randomly when disturbed (really randomly). Looks like vibrations but that's not it. It was sweet for 2.4.2 if it were not for software problems...

Hi Randy,

My Quad using software 2.4.1 was working in all Modes without problems using the default settings.  Using a APM1,  standard motors and ESC.

Under software 2.5 -

I am still having problems with ALT_HOLD and RTL with Quad dropping to ground when these two modes are selected  even though TRIM_THROTTLE has incremented to 528 after several flights.  Stability Mode is working the best I have seen the Quad operate.     What other setting can I try to resolve this problem?

Regards David

thanks!  I just placed an order!  let's see if I can have the bird in shape when I get those new props ;-)

Random yaws movements are mostly related to interferences between ESC´s and magnetometer.

This is some kind of "misterious" to solvet since there are many factors that affect.

Some recomendations are:

- increase the distance of ESC´s (and cables) from magneto

- swing around all power cables (this helps a lot)

- change positions of ESC´s

You can check this effect by ploting log´s yaw signal vs thrust (power). You will see interferenced signal when thust is hight.

Hope this can help you


That's not it - in my case it yaws and holds - it would not do that if it was interference problem (it would yaw during interference and then yaw back, right?). Also, it started with newer software versions while my hardware hasn't changed. And the power distribution is good distance from my sensors... There were more people complaining about this, I hope we're not all having interference problems, but for now I rule it out.

Hi all

Just tested ALT_HOLD for the first time (at 450) and get the same result - rockets upward. 


James, what's your value after reconnecting, has it changed? I posted an issue here as this is going to catch out a lot of people if it persists.

Hey Jan

My Problem is the absolutly NOT stable flight. It nicks, and rolls , like wobbling, but its not an oscillating, its more like a spiteful horse. If i deactivate the Compass, its the same. Ive the problems with the "root flight mode", acro, stable and so on. Sometimes, my Hexa isnt responding to my rc input. Sometimes it does movements, that i dont given. Like nicking hard and flying away. Its very turbulent in the air.

My Sensors are all working properly, so its not a hardware problem.

I´ve only 2 modes, how my hexa flies: very sluggish or wobbling. So i tried all possible PID tunings. Dont work. I showed in some Videos my Test Flights, in this i showed how the Hexa flies with e.g. the MultiWii Code. Works. But i would fly with the AC. ;)

Flown another Systems on this Hexa. Works very well. So i have to search in the AC Code. (or u, because im not a coder). Actually i havnt my Arducopter here, so  if i have it back, i will post some logs.

As i said, maybe have another ppl a different opinion of the definition of "stable". MultiWii in my Hexa is stable - AC isnt. So i hope we can dig in the code and maybe theres a problem.

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