Copter-3.3 beta testing

Warning #1: an issue has been found with Tower's Pause button which can cause the vehicle to fly to an old position if the vehicle has not sent a position update to Tower in some time.

Warning #2: Copter-3.3.2 fixes a bug found in Copter-3.3.1's desired climb rate initialisation which could lead to a sudden momentary drop when switching from Stabilize or Acro to AltHold, Loiter or PosHold.

Warning #3: Copter-3.3.2 fixes an issue found in Copter-3.3.1 which could lead to hard landings in RTL or AUTO if the WPNAV_SPEED_DN was set too high (i.e. >400 or 4m/s) and/or the WPNAV_ACCEL_Z was set too low (i.e. <100 or 1m/s/s).

Warning #4: a bug was found in Copter-3.3 which could cause a sudden crash if you abort a Take-off initiated from a ground station.  Video description is here.  The bug is fixed in Copter-3.3.1 so we recommend upgrading.

Note #1: AC3.3-rc8 corrected a long standing bug in the HDOP reporting.  HDOP values will appear about 40% lower than previously but this does not actually mean the GPS position is better than before.
Note #2: if upgrading from AC3.2.1 the vehicle's accelerometer calibration needs to be done again.
Note #3: set SERIAL2_PROTOCOL to "3" and reboot the board to enable FrSky telemetry like in previous versions.
Note #4: the wiki will be updated over the next few weeks to explain how to use the new features

Copter-3.3.1 is available through the mission planner.  The full list of changes vs AC3.2.1 can be see in the ReleaseNotes and below are the most recent changes since AC3.3.

Sadly this version (and all future versions) will not run on the APM2.x boards due to CPU speed, flash and RAM restrictions.

Changes from 3.3:

1) Bug fix to prevent potential crash if Follow-Me is used after an aborted takeoff

2) compiler upgraded to 4.9.3 (runs slightly faster than 4.7.2 which was used previously)

Changes from 3.3-rc11:

1) EKF recovers from pre-arm "Compass variance" failure if compasses are consistent

Changes from 3.3-rc10:

1) PreArm "Need 3D Fix" message replaced with detailed reason from EKF

Changes from 3.3-rc9
1) EKF improvements:
    a) simpler optical flow takeoff check
2) Bug Fixes/Minor enhancements:
    a) fix INS3_USE parameter eeprom location
    b) fix SToRM32 serial protocol driver to work with recent versions
    c) increase motor pwm->thrust conversion (aka MOT_THST_EXPO) to 0.65 (was 0.50)
    d) Firmware version sent to GCS in AUTOPILOT_VERSION message
3) Safety:
    a) pre-arm check of compass variance if arming in Loiter, PosHold, Guided
    b) always check GPS before arming in Loiter (previously could be disabled if ARMING_CHECK=0)
    c) sanity check locations received from GCS for follow-me, do-set-home, do-set-ROI
    d) fix optical flow failsafe (was not always triggering LAND when optical flow failed)
    e) failsafe RTL vs LAND decision based on hardcoded 5m from home check (previously used WPNAV_RADIUS parameter)

Thanks for your testing!

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        • Dave,  MAG_ENABLE is not the param you want. Look for COMPASS_USE in the full param list. You can enable/disable each compass. I haven't tried this, my compass works great and I found all 3 enabled and I don't have a #3 compass. I have never don a compass_mot cal. I just assumed I am using the external compass on a mast. If one has failed, turning it off could get you flying. Maybe I should do a compass mot cal in case I loose the primary compass.

  • Another thing I notice. I'm flying with only int compass until I solve ext one, I calibrate and all looks well but flying with Tower, in middle fligth without changing nothing flag EXF (great tool) becomes orange and red, then I do another fligth but with no Tower but notice in the two logs that offset changes, that's common? I never see in other logs. (one log is the same share.)3702099685?profile=original

  • here the log

    2015-09-26 10-23-27.bin
  • I test 3.3 rc12, It's looks much stable than 3.2.1 but I change many things to evalute exact difference, (controller, dampening system and firm). The only problem I still have is mantain altitude, I notice that repeat similar issue than the APM so, I hope I'm having mistakes tunning it, It's looks that baro overreact? which param work exact there? (with APM I try Throttle accel, rate and ALT P ) Thank's


  • I'm running the latest 3.3 RC12.
    I did see that note.
    And I can see why its there for safety, but then it removes any form of RTL or GPS mode tests indoors.
    (eg..making sure FS kicks in, on TX off)

    But even if I ARM in STAB mode, I can't go into any of the GPS modes afterwards.
    So trying to Arm in PosHold mode, at least gave an answer to why not.

    Basically it seems like this new safety feature completely removes all GPS modes based on GPS Pre-Arm failure.
    Good for safely, bad for testing.
    That kind of defeats the whole purpose of having the Pre-Arm Check disable feature. And degradees the flexibility of this system.

    Maybe a better solution would be to re-instate the Pre-Arm disable, and instead show status message that All Pre-Arm checks are disable.

    Going further, you could force the user to double arm. while in PreArm check OFF mode.
    At least the will to that fact that your in that mode.

    What do you think Randy?

    • Developer


      As you mentioned, it was dangerous in practice to allow people to arm and take-off in a mode that requires the EKF to have a good position estimate (i.e. Loiter, PosHold) without enforcing that that estimate is actually good.  I don't think we can go back on that really so instead, if this change has made testing the failsafe more difficult perhaps we should just try and make that testing easier.

      • Nick/Randy,

        Am I missing something but isn't testing the THR failsafe the same no matter what mode you are in?

        I thought that testing the failsafe in STAB or ALTHOLD was the same as testing it from one of the GPS modes. 

        I don't quite understand why you need to be in a GPS mode to test the FS behaviour.  For me, I would rather keep the arming checks as they are. It lets me know when the EKF is happy and I can choose to fly in non GPS modes. When I can ARM in a GPS mode (or with the Fence enabled) I know for sure that the EKF is happy and that things such as home/origin will be set and things like RTL will work.

        I have not had any issues setting the THR FS and testing it in STAB.  If that works it has always worked in every mode if I fly too far or I switch the Tx off.

        • Alex, one difference that would occur when testing Throttle FS, would be that if you have GPS, it will RTL.  If you don't have a GPS, then I believe it will basically go into Alt Hold and land straight down.

          • Thanks Rob, good point. I do realise that this is the case.

            I guess I was just trying to reassure Nick that testing the failsafe indoors without the GPS lock  is fine. You can be confident that the failsafe  code will select RTL (if that is how it is set) when flying with a good GPS lock after.

            I find it reasuring to see the FS go to through the non-GPS proceedure as it reminds me what will happen if I loose both GPS and Rx signal (i.e. absolute worst case).

            Once I have seen the FS work without GPS on the bench, I feel confident tesing in flight with GPS.  Of course, I only ever check the failsafe behaviour AFTER making sure that RTL works by switching to it manually.  That letts me know that all of the GPS/EKF nav code is happy enough to get me home before I try turning off my Tx.

            Mybe I am trusting the code too much but so far it has behaved as expected. 

  • 3702099061?profile=originalNot sure if this is bug, or if I'm just missing something.

    I'm doing some bench testing and trying to test TRL triggers.

    Problem is I cannot going into any of the GPS modes, probably because of a bad GPS signal indoors.

    So I DISABLED all the PreArm checks.

    However it still does not work.

    When disarmed I can change to all flight modes.

    So I changed to PosHold mode while Disarmed.

    And then proceeded to Arm.

    I got an error Message.

    PRE-ARM: GPS Horiz Error

    I thought that disabling PreArm checks, bypassed ALL checks?

This reply was deleted.