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.

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  • Randy,

    First - let me add my thanks to all the developers and to you Randy for all the great work you have done and are doing.

    I have been trying to tune my HK Talon/3DR quad.  I got several good but short flights in STAB, ALT HOLD and LOITER modes.  I wanted to put together a log set from longer flights in each mode.

    I flew in STAB. mode for several minuets, tried some monuievering and all went well. I switched to ALT HOLD.  After verifying that the altitude was holding, I tried to do some monuevering.  I rolled to the left - the quad seemed to shoot off to the left, I tried to correct but the quad flew into a grassy hill behind me.  

    The quad is: 560 mm, Cobra 2213/26  Kv950 motors, HK Plush 25A ESCs, 10X4.5 GF props, 3300mAh 25C LiPo.

    I cannot find the cause for the crash.  Here are the logs:

    Thank you.

    2013-07-24 09-50-42.tlog

    2013-07-24 10-32 1.log
  • MR60

    Need second (or more) opinion for vibrations:

    I see in my last Tlog what seems to me huge xacc and yacc values (while zacc seems ok within plus or minus 0.2g) : is it a mission planner display scaling thing or a huge problem with my vibrations ? enclosed my tlog and graph below:


    I notice also a difference of "zeroing" between X and Y axis : why is that ?

    2013-07-24 15-33-42.tlog
  • Randy.

    You may have seen the debate regarding reliability and redundancy.

    Could I ask, in all the logs and problems you have looked at how many times have you seen an APM just fail, not caused by power problems.


    Perhaps we could do a histogram survey page about the causes of peoples crashes. Categories like.







    APM power



    Other mechanical

    Pilot (Tuning/PID/settings)

    Pilot (flying errors).




  • 3692782104?profile=original

    This is one of my mission logs just to demonstrate how sporadic gps aberrations can be. These spikes in HDOP caused 7 to 8 meter altitude changes.. I was following the HDOP in real time and was expecting losing GPS lock any second, but it settled down and continued a safe completion and RTL.. How bad do these numbers have to be to lose lock for 4 seconds? The satellite predictor looked adequate during this time frame..

    2013-07-20 23-27 2.log

  • Hi Randy ...Are you able to check my logs just once more?3692781801?profile=original3692781692?profile=original ..I have redone the APM Mount ..picture attached ..  all seems good flys well ..just a bit of mild dipping on the arms when hovering.. 

    2013-07-24 13-49 1.log

  • Hi when upgrading MP does it load default PIDs and change my settings ...or does it remember all my params ..I know that Params are stored on the APM as Randy had said ..I was just wondering how updrading MP affects settings do i need to redo set ups such as compassmot Acc calibration etc.. ? 

    P.S I have discovered that when mounting the APM onto a weighted rubber/ cushioned isolated plate it is a great idea to fix all wires the attach to the APM onto the same plate leaving a little slack going to the APM ...this way any vibes travelling up from the wires is arrested by having them fixed to the Ali plate...before they attach to the APM .cheers

  • Every now and then I get a Loiter "zinger" shown as a linear pitch/roll command by the APM in the image. This only seems to happen in a high wind situation (16kts gusting in all directions to almost 20kts). The loiter will appear as if it is holding but being stressed heavily by the wind and then all of a sudden it zings off laterally (elevation is not too bad). Most of the time if I let it, it will wander back to reality in it's proper gps loiter position but sometimes not. I am just wondering if the "Imax" term is stretched to the limit under the stress of holding the copter in position and it is just unloading?? The logs show this weird scenario when it happens: The gps hdop and number of sats appear to be okay as shown in the image. Logs are attached... Thanks for looking.


    2013-07-23 16-29 1_loiter_zinger.log

  • Has anybody got a APM 2.5 version 2.9.1b hex file for a quadcopter for me so that I can get to fly again?


  • Hi, I just updated my APM2.5 from 2.9.1b to 3.0.1 and I noticed that now the artificial horizon in the Mission Planner (1.2.61) does something strange: As you see in the sceenshot it shows a pitch of -5deg although the copter is located perfectly horizontal (shown by the numbers below). What's the matter? I made the Accel Calibration several times, so that can't be the problem...



  • When switching from stab to loiter it can be quite violent and can sometimes topple the gimbal or show part of the frame in the shot. Its probably mostly because I have some vertical or horizontal speed at the time but at distance it can be hard to judge that. Is there anything in the settings that may soften the entry to loiter without reducing the loiter accuracy its self. If not might it be possible to have ‘soft entry’ to loiter?




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