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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          • and you also weighted it down or flipped prop when it was like that? but i flew fine anyway?

  • Here is an another log, from other session that had an oddity.

    radio was not turned off, really. yet I see failsafe for Err Radio in there - but may be I walked too close to the drone, but from other perspective in same timeframe with this red banner for 'Err Radio' and 'failsafe radio' you can see how I tried to switch flying modes - so radio link was on and working. Odd.

    What was peculiar - it was a third session, and I unplugged battery, plugged it back on, saw 12 sats on the minimOSD screen, tried to arm drone but it responded - 'need 3d fix' and refused to arm. it continued like that for a while and then finally it decided to arm.

    as it flew before for 5 min or so and GPS was in lock with blue led on - I am not sure what is the deal about that.

    In GPS glitch I see green line with sats count to begin kinda late, what is that about? How can it be different with what minimOSD shows on the screen? I saw 3D lock status icon on taranis telemetry as well at same time.

    PS. So, a first GPS data shows in line 1188, at 10:13:54.

    log starts at 10:13.04. as it can be seen I was able to arm it at 10:14:19. Was it a mandatory delay? Why it was saying me it has no 3D fix al that time ?


  • Developer


    It's hard to be sure but unlike for super simple mode, I'm pretty confident that simple mode is ok because it gets so much use.  Maybe the friend didn't know that the heading of the copter at the moment it was armed is important?  That's a guess, I'll need a log for sure... we've changed a lot of anything is possible.

    • Randy,

      in addition to the log I provided - could you pls explain how exactly logic for super simple mode even works?

      How does it know where I am located with the transmitter? Why does it go crazy like that when it gets close to the operator?

      PS. on the response with a log I said - 'RTL did not do anything', I am not sure about it actually, but I think it actually drove drone right into my neighbor's flower patch, in the opposite direction from a proper startup spot, and it may correlate with same wrong directional inputs from the remote. but I am not sure. it all happened very quickly and as it started killing flowers with props I killed its motors.

      • Developer


        Sorry for the slow reply.  Super simple mode assumes the pilot is at the vehicle's home location.  I guess in practice the user is a few meters away from the home position but normally it's close enough.

    • hi, I was 'lucky' to get it on my first attempt, if you look at vibrations log there is a spike close to 3min mark - it is where it dropped on ground as all controls went erratic and I then killed motors, prior to that trying to do RTL that did not do anything.

      Pls advice if you will see anything in there.

      I then tried 3 times - and got nothing. 'super simple' mode is attached to channel 11. 'simple' mode is on channel 10. I did not see any issue with 'simple' mode during this test and after first incident with super simple mode it then worked fine on 3 subsequent take offs, close and far.


  • Hi Leonard, Randy and Dev team,

    I was wondering what the value of ekfposhor should be in the HUD?


  • Gentleman please see attached log from todays fpv flight.

    Pitch angle 55°

    Speed Peak 32m/s

    No significant vibrations

    AltHold perfectly straight


    2015-06-17 19-24-36.bin

    • Developer

      Hi Pomaroli,


      Have you got some photos and specifications you an share with us?

      • Leonard,

        to make it really short, it is the common DJI F550 frame with Pixhawk Kit and Fatshark for FPV.

        The most important thing to know is that an antivibration mount has to be used, this one below works best

        3702705004?profile=originalAlso concentricity of Propeller mount is very important,  best is to use this type of adapter.

        3702704913?profile=originalIf more details are needed i can open a separate thread for it. Perhaps i'll do a tutorial next time i build one.

This reply was deleted.


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