ArduCopter-3.0.1 released!

ArduCopter 3.0.1 has been released and is now available in the Mission Planner,, GitHub and the new Downloads Area.

Warning #1: Compass calibration and reducing interference is far more important than with 2.9.1b

Warning #2: GPS glitches can cause sudden and aggressive position changes while in loiter mode.  You may wish to reduce the Loiter PID P to 0.5 (from 1.0) to reduce aggressiveness (see image below of where this gain can be found in mission planner).

Warning #3: optical flow is not supported but will be back in the next release (AC-3.0.2 or AC-3.1.0).

Warning #4: loiter turns does not maintain altitude.  This bug will be fixed in AC-3.0.2.

Warning #5: This release has only been lightly tested on Traditional Helicopters.

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 (get it here)

2. Click on the MissionPlanner's Hardware, Install Firmware screen.  The version numbers should appear as "ArduCopter-3.0.1", 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. Although not directly related to this release, if you purchased an APM prior to March of 2013, update your PPM encoder to the latest firmware (instructions here).

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

Numerous How-To videos are available:

Special Thanks to MarcoDaveC and the large number of testers on the pre-release thread who put 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.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • Arducopter 3.1 rc3

    No bug reports, no complaints, no .tlog .log etc, only good experience! Tested new lipos (5Ah+4Ah) on HexaCheers for Loiter, ~3.5kg. Cheers DevTeam!

  • I have an older apm 1.0 board are there any changes that need to be made to make this work.  Thanks for the great work! 

  • One question...since i will be ordering Pixhawk (APM 2 is too old,its time to move on...)and other components,

    should i order PX4FLOW as well or it is to early to have any real use of that?

  • T3

    Dear all,

    I have some fail save questions: 

    I have set Low_Volt (what is now called FS_Batt_Voltage) to 14V. At 13.7V Land mode was triggered but the copter remained in some Loiter state. Where can I define "what action to take". I am preferring RTL. The 13.7V might come from a mixing of decimal separators in the German version - but I am not sure. 

    For the Fence Action one can select "RTL or Land". Can these be specified somewhere? 

    Thanks in advance,


    PS: 3.1rc2 worked flawless on my long endurance hexa (link 1, link 2) in Auto missions with CAM_TRIGG_DIST, Loiter and Stabilize. Now I am in the process of switching to rc3.

  • Developer


    You say that is APM 2.5/2.6 is near its CPU limit and almost no space to grow new functions. Does that mean that Arducopter-3.2 (example) can have new functions that will work on Pixhawk but not on APM? Or you will hold back the development to accomodate APM CPU? I mean, when are you step up to pixhawk on a firmware?

  • Moderator

    As posts tend to get a bit lost in this fast-moving 220 page thread, I've documented my odd problem of my APM2.5 not 'seeing' my functional external compass here:

    Any insight there would be very welcome!

  • Why am I getting multiple RTL commands when a single one is sent?

    I posted this question outside this thread, but got no bites.  I apologize for asking it again here, but this is an issue that affects my flight.

    I'm using a 3DR Hex with an APM2.5 running the 3.01 firmware.  (I have no problems with anything else..  Loiter, Alt Hold etc. all work well).

    I have RTL set up for geofence and TX loss... I also have a switch position on my  transmitter configured to trigger an RTL.

    Whenever an RTL is set, I get mulitple RTLs following the initial one.  I can get up to 30 RTLs logged  when only one should be needed.   This happens when the fence is breached, the TX signal is lost and when I click my mode switch to RTL.

    What's annoying is that each subsequent and unwanted RTL causes my hex to pitch and tilt.  Below are snips of two logs showing what I mean.   The one showing almost 30 RTLs resulted from a fence breach.  The one with around 10 was created when I clicked the RTL on my transmitter..  Does anyone else experience this..  If not, where should I look to fix this problem?


  • Hi Randy,

    Could you make THROTTLE_IN_DEADBAND a configurable parameter to reduce (if we want) the deadband for ALT_HOLD ?



  • Hi Michael,

    If you have a Hexa try with Dataflashlog setting: disable all.

    After this I had no more such Spikes. (Also in Pitch and Roll Axis)

    My be AMP is to busy with more than 4 Motors and all the Logs (Dataflash an Teleterie)

    As I could read People with Quadros are happy.


  • This is cool and I think useful for noob like me.3692851499?profile=original

This reply was deleted.


Gremsy liked Gremsy's profile
Mar 12
DIY Robocars via Twitter
RT @chr1sa: Donkeycar 4.4 released with tons of new features, including path learning (useful with GPS outdoors), better Web and Lidar supp…
Nov 27, 2022
DIY Robocars via Twitter
RT @NXP: We are already biting our nails in anticipation of the #NXPCupEMEA challenge! 😉 Did you know there are great cash prizes to be won…
Nov 24, 2022
DIY Robocars via Twitter
RT @gclue_akira: レースまであと3日。今回のコースは激ムズかも。あと一歩 #jetracer
Nov 24, 2022
DIY Robocars via Twitter
UC Berkeley's DIY robocar program
Nov 24, 2022
DIY Robocars via Twitter
RT @chr1sa: The next @DIYRobocars autonomous car race at @circuitlaunch will be on Sat, Dec 10. Thrills, spills and a Brazilian BBQ. Fun…
Nov 24, 2022
DIY Robocars via Twitter
RT @arthiak_tc: Donkey car platform ... Still training uses behavioral cloning #TCXpo #diyrobocar @OttawaAVGroup
Nov 20, 2022
DIY Robocars via Twitter
RT @emurmur77: Points for style. @donkeycar racing in @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video.…
Nov 20, 2022
DIY Robocars via Twitter
RT @SmallpixelCar: Going to @diyrobocars race at @UCSDJacobs
Nov 8, 2022
DIY Robocars via Twitter
RT @SmallpixelCar: Race @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video.
Nov 8, 2022
DIY Robocars via Twitter
RT @PiWarsRobotics: Presenting: the Hacky Racers Robotic Racing Series in collaboration with #PiWars. Find out more and register your inter…
Oct 23, 2022
DIY Robocars via Twitter
RT @Hacky_Racers: There will be three classes at this event: A4, A2, and Hacky Racer! A4 and A2 are based around UK paper sizing and existi…
Oct 23, 2022
DIY Robocars via Twitter
Oct 23, 2022
DIY Robocars via Twitter
Oct 19, 2022
DIY Robocars via Twitter
Oct 18, 2022
DIY Robocars via Twitter
RT @NeaveEng: Calling all UK based folks interested in @diyrobocars, @f1tenth, @donkey_car, and similar robot racing competitions! @hacky_r…
Oct 13, 2022