ArduCopter 3.0 is ready for widespread use.  To make the transition easier, this time we are asking people to voluntarily upgrade from 2.9.1b for the next month or so before we make 3.0 the default firmware downloaded by the mission planner.  The new version can be found in the Mission Planner's Beta firmware's link,, GitHub and the new Downloads Area.

Warning #1: A bug was found in the FENCE in which if you lost GPS it could lean at extreme angles as it tried to maintain an invalid position.  This is fixed in AC3.0.1-rc1.

Warning #2: This release has not been fully tested on Traditional Helicopters

Warning #3: GPS glitches can cause sudden and aggressive position changes while in loiter mode.  You may wish to reduce the WPNAV_ACCEL to 100 and Loiter PID to 0.2 (from 1.0) to reduce aggressiveness.

Improvements over 2.9.1b include:

  • Inertial Navigation for Loiter and Auto meaning much more accurate control (Randy,Leonard,JonathanC)
  • 3D navigation controller follows straight lines in all dimensions between waypoints (Leonard,Randy)

         WPNAV_SPEED, WPNAV_SPEED_UP, WPNAV_SPEED_DN, WPNAV_ACCEL allows configuring speeds and acceleration during missions

  • "compassmot" to compensate for interference on compass from the pdb, motors, ESCs and battery.  (Randy,JonathanC) (Set-up video here)
  • Safety improvements:
    • simple Tin Can shaped Geo Fence
    • pre-arm checks to ensure all calibration has been performed before arming (can be disabled by setting ARMING_CHECK to zero).  (video description here)
    • GPS failsafe - switches to LAND if GPS is lost for 5 seconds
    • stability patch improvements to stop rapid climbs in very overpowered or overtuned copters
  • Circle mode improvements including "panorama" when CIRCLE_RADIUS set to zero (Randy,Leonard)
  • SONAR_GAIN parameter added to allow better tuning of sonar surface tracking
  • CH8 auxiliary switch (same features as CH7)
  • works on PX4 (some minor features still not available) (Tridge,PatH)

How to upgrade:

1. Make sure you are using Mission Planner 1.2.59 or newer.

2. Click on the MissionPlanner's Firmware screen and click the "Beta Firmwares" link on the bottom right.  The version numbers should update to "ArduCopter-3.0.1rc2", then click the appropriate frame icon and it should upgrade as per usual.

3. Reduce the Loiter and Alt Hold PIDs if you have modified them from the defaults.  The modified PID values for the 3dr frame can be seen in the image below.

Note: Nav parameters have been combined with Loiter so do not be concerned if you can't find them.

4. If you purchased an APM prior to March of 2013, update your PPM encoder to the latest firmware.

5. Try out the new version in stabilize mode first, then alt-hold, then loiter and finally RTL and Auto.

Special Thanks to MarcoDaveC and the rest of the beta testers for putting their copters at risk during the extended testing period.  Some of their videos can be found hereherehereherehere and here.  Thanks also to MichaelO for the MP changes required for this release.

All feedback welcome.  Please put your questions, comments (good and bad!) below.  

Added by Craig:

Please watch Randy's videos on setting up and flying APM-Copter 3.0 before you go flying.  They are excellent!

3DR Quad Set-Up Suggestions
AC 3.0 "Live" Compass Calibration
AC 3.0 CompassMot Setup      
AC 3.0 Pre-Arm Checks            
AC 3.0 Fence                               
AC 3.0 Maiden Flight Checks   

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Thanks Randy for the issue raised, hope it will be fixed soon.

Excellent, thanks.

Thanks, i must be blind ;o)

Hi Randy, attached my log file. I can see some noise on the BarAlt, and the effect on the smoothened Alt graph. She had a good run and was loitering quite stable and this happened as soon as I started yawing. My H's arms are mounted in a foam sleeve and my AP is on a foam pad. I'll have to check if the yaw does not flatten my arm mount foam and touch the fuselage.




Randy. just had a quick flight with stab, loiter and auto. This is with the mot stuff all zero. Here are the files. Im very happy with it but perhaps you can tell why the compassmot is making things bad.

By the way can you tell why one WP (6?) is still snatching while the others are silky smooth?

Cheers Vince


I cannot do the compassmot, I always get this error: Failed! Compensation disabled. Did you forget to raise the throttle high enough? I have raised it to 75% for 5 seconds and quickly pulled the stick down, to 80%, 90%, 100%, even tried just 50% , I always get the same result. I followed the instructions per this video to the T: 

Any help/advice would be appreciated :)

The use of a comma or a decimal place depends on the local settings on your pc. The declination is entered in degrees but is stored in radians.  When you view it in the advanced parameters list it will be shown in radians

I thought it might be worth trying to put an overall perspective on the "New" GPS warning.
There are basically 3 reasons for the GPS warning.
A. We have just figured out the potential greatest magnitude of the problem which is entirely related to GPS and not basically "fixable" except with military grade (externally ground source secondary transmitter) compensation. - (and that seriously isn't going to happen)
B. It is definitely worse during the high solar activity, more common for the next 2 years than normal, but still quite rare.
C. Because of the ability to respond faster, we have tweaked the response rates ~ 2.5x (which can be reset back to their previous levels) removing the aggressively part of the warning so you have time to respond.
The increase in response rates lets the copter hold position more tightly especially in gusting wind conditions and lets auto fly successfully and more accurately in conditions where it could not before.
Whatever you say about this system, it is going to be reflected identically in all systems relying on GPS for position determination including airplanes in flight (except the military and really big jets who can access real time compensation (with really expensive equipment) as well).
In fact, dialing down the nav response rate back towards the original values really removes the "panic" from this problem and will give you enough time to compensate for a wild GPS position, the only negatives are that it won't maintain as tight a loiter in gusty conditions and will be a little "sloppy" waypoint following.
The bottom line is that this is a pernicious problem relating to depending on GPS for absolute position maintenance and the only really satisfactory solution is to have an alternate and dependable method for position determination.
Possibly a fixed object that you could determine your position and motion relative to. 
Nobody else has got this yet either (well my guess is the military does by now, but they certainly aren't talking about it.)
In fact, the Optical Flow camera is designed to do exactly that: show your ground relative motion.
Although they haven't talked about it much, the thing that could help Optical Flow the most is a stabilizing platform for keeping it pointed straight down regardless of airframe attitude. 
Think about it, if the camera is bouncing all over the place, you then have to compensate by continuously shifting the image: computational nightmare or at least a time intensive pain in the program.
For your use for now, If you are uncomfortable with mastering the 1 second switch back to stabilize move, I would just dial back the nav rate parameters then you should have the advantages of inertial in loiter with the only drawback that it won't compensate as quickly in gusty conditions and might be a bit sloppier. 
(It will still compensate better than the older versions, just not as quickly as with the rates set higher.)
Until we can incorporate a secondary position or motion determination system (not GPS) this is a fact of life for the APM / PX4 and every other GPS dependent flight controller out there.
Notice that even the new Naza system went to a lot of trouble to not actually use the GPS to actually do anything.
And the WooKong has exactly the same problems in this regard we do, remember New Zealand, that was a WooKong GPS pod sticking up and GPS multipath killed it deader than a door nail.
Optical flow could go a long way to providing an answer in the long run (fog could be a problem though).

Randy and Dev Team,

Just need clarification regarding INS_MPU6K_FILTER setting.


I noticed that in 2.9.1b release the INS_MPU6K_FILTER setting was changed to 20hz as per the release notes.


Now with this release 3.0 in the Mission Planner, in the Advance Parameter List under the description for INS_MPU6K_FILTER, it reads that this setting should be set 42hz for Arducopter and 20hz for Arduplane. However, there is no mention of the INS_MPU6K_FILTER setting being changed back to 42hz in the 3.0 release notes.


Which is the correct INS_MPU6K_FILTER setting for the 3.0 release for Arducopter, 42hz or 20hz?

I commend you all for this release.


Thank you!

Dear Randy,


thank you for support.


it's the first time to me. i have been flying many times before with 2.9.1b RC3; and only few time saw that there was fast descent but only ~1m not more (in RC3) when it reaches WP. but at this last time was more or less 10 meters jumping. what is most strange that it happened when it reached WP.


baro is covered and in plastic (not original).


let's see today i adjusted some NAV parameters to slow down arducopter and first flight in same area was OK of course not in AUTO. 


I'll come back if i'll find reason


thank you very much

42Hz is typo or error of some sort.

See this:

The default value on ArduPlane, APMrover2 and ArduCopter is 20Hz.

What version of Mission Planner are you using? Where are you reading it says 42Hz?

I'm using the latest version of the Mission Planner, version 1.2.53.

It's in the Advance Parameters List, scroll down to INS_MPU6K_FILTER, it's in the description field.


Thanks, Craig.

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