ArduCopter 3.2.1 released

Warning: there was a period of about 12 hours after this blog was first posted where an older version (AC3.1.2) replaced AC3.2.1 for APM2.  If you think you may have downloaded for the APM2 during these initial period, please check the version on your board by looking at the title bar of the Mission Planner (see the 5th comment from me below for a screenshot)

ArduCopter 3.2.1 has completed beta testing and has been released as the official version available through the mission planner and other ground stations.  If upgrading from AC3.2 there should be no need to re-do any configuration.

Changes from AC3.2 are listed below and in the ReleaseNotes:
1) Enhancements:
    a) reduced twitch when passing Spline waypoints
    b) Faster disarm after landing in Auto, Land, RTL
    c) Pixhawk LED turns green before arming only after GPS HDOP falls below 2.3 (only in flight modes requiring GPS)
2) Safety Features:
    a) Add desired descent rate check to reduce chance of false-positive on landing check
    b) improved MPU6k health monitoring and re-configuration in case of in-flight failure
    c) Rally point distance check reduced to 300m (reduces chance of RTL to far away forgotten Rally point)
    d) auto-disarm if vehicle is landed for 15seconds even in Auto, Guided, RTL, Circle
    e) fence breach while vehicle is landed causes vehicle to disarm (previously did RTL)
3) Bug Fixes:
    a) Check flight mode even when arming from GCS (previously it was possible to arm in RTL mode if arming was initiated from GCS)
    b) Send vehicle target destination in RTL, Guided (allows GCS to show where vehicle is flying to in these modes)
    c) PosHold wind compensation fix
    d) prevent infinite loop with do-jump commands pointing at each other
    e) pixhawk memory corruption fix when connecting via USB
    f) vehicle stops at fence's alt limit in Loiter, AltHold, PosHold (as it did in AC3.1.5)
    g) protect against multiple arming messages from GCS causing gyro calibratoin failure

Thanks very much to Marco and our beta testers who put their copters at risk over the past several weeks to help us iron out these issues.  Also Thanks to Raph for the video (this is actually a video from AC3.2).

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  • Developer


    Thanks for the report.  That's a nasty problem I haven't seen before.  It appears the first mission item is invalid.  It's command 255 which does not exist.  I've tried to reproduce this in both AC3.2.1 and the newer AC3.3 but I've been unable to get the invalid command to upload to the vehicle.

    It's really not clear how this command got in there but I think if you can clear out that mission it'll probably be fine.  We can look into how this happened a bit more after your feedback.

  • How could it happen to have 4 bad missions in a row ? Being two of them created with Mission Planner and the other 2 with tower app.

    I'm gonna try to log more stuff and repeat this. However, this time I wont be able to fly over water to avoid a major crash :/

  • Don't know, maybe your TRIM_THROTTLE is set to high at 607 instead of 475 or you have a bad mission.

    Throttle out goes to minimum when you set it to Auto.  Need to have logging set higher so we can see more data.
  • hi 

    I almost had three crash's about a month ago and still cant figure it out

    They all happen as soon as I engage AUTO mode, the quad droped altitude very fast (if i'm not mistaken the motors turned off) and I had to switch to stabilize and apply full throttle to recover it, one of the first times it actually touched the water when it recovered. 

    I cant understand what did really happened, why did it fall like a rock when AUTO was engaged ?

    the mission was initially planned with mission planner, and in the second time I tried tower, but gave me the same result.

    The last time it goes to AUTO I can understand that the problem can be related to the high hdop and the quad tried to hit a wall, luckily I switched to PosHold and recovered in the last second!

    Log here:

    Dropbox - Error
    Dropbox is a free service that lets you bring your photos, docs, and videos anywhere and share them easily. Never email yourself a file again!
  • Is like your baro alt diverge with alt, for vibration consecuences, vibs affect baro; you have to see what the reason for that suddenly vibration, like a mechanical problem


  • Hi Cala,

    thank you for your answer.

    Yes i have tested the geo fence function.

    That is ok, but the yellow marked is the problem.


  • Perhaps you have your fence programmed to 100 mts? and your copter reaches it and try RTL because you have fence failsafe enabled, check that


  • Hello,

    yesterday i flew the 3.2.1 the first time after a crash with my Tarot 650 last year.

    Everything was OK but in PosHold Mode the copter suddenly was pull up the Motors and was going up and away a short time. I have switched back to Stable mode an then i controlled the copter again. This is not the first time i have had this before in 3.2 beta  versions. Can someone have a look to the Log?. 150000 -151450  there is the switch back to Stab mode.  Logfile



  • Developer


    The compiled binaries for all the different frames can be found here.  Generally people use the mission planner (or other GCS) to upload to their boards though.

  • And the download link to ArduCopter 3.2.1 released is...?

This reply was deleted.