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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    • Developer


      That's no fun.  Yes, it's very possible that you're right.  We've greatly increased the logging which helps a lot for digging into support issues (especially those involving the EKF) but has made downloading much slower and occasionally messages are lost if you're not using a high quality card.

      I'll bring this up with the other devs (I've brought it up before as well) as a counter-weight to the constant desire for more data.  We do actually have some plans to change the way we log.  So instead of turning on/off individual messages, we hope to allow selecting the amount of data you want (i.e. "none", "small" "medium", "detailed").

      Sorry for the troubles.

      • Hi Randy ...just to say thanks for your reply .. I have fitted a faster card i will see how that goes .. .. I have a concern with compass bar going into the red when the copter turns in Auto mode .. I have tried this with just a bare spare pixhawk board plugged into the PC, I get a similar result when move by hand .. otherwise the copter seems to be behaving it self now .. the green bars hardly move on the EKF monitor ..just compass getting up but only some times ..I have the internal compass disabled .. your thoughts ?

      • T3

        Reuben and Randy,

        I had no problems so far with missing CAM messages.

        So maybe it is the SD card. I alway use the fastest I can get.

        I hope "none", "small" "medium" and "detailed" is only an additional option and that individual settings will still allowed. "none", "small" "medium" and "detailed" might be good for beginners. Hence, I like the idea. But as soon as you have specific requirements the best way is to select it manually. For sure one has to test it and (maybe) adjust the amount of data logged accordingly...

        Best regards,


        • Hi Thorsten, I have not had an opportunity yet to see if the class 10 card I fitted has fixed the issue.. I will find out though one way or the other ..I am not sure I like the "None Small Medium and Detailed" logging options, I prefer to select specific items to log .. 

  • Developer

         We’ve pushed out Copter-3.3.3-rc2 for testing and it should appear in the mission planner’s beta firmware link in about an hour.  This beta release includes just a couple of small fixes found over the past couple of weeks.


    Changes from 3.3.3-rc1:

    1) bug fix to Guided mode's velocity controller to run at 400hz (results in smoother throttle when using the velocity controller - which few people use)

    2) bug fix to MAVLink routing to allow camera messages to reach MAVLink enabled cameras and gimbals (including SToRM32)

    Thanks for testing!

  • Hi Randy.

    I tried the new version arducopter 3.3.3rc1 and I noticed that the RSSI value is not on the telemetry . I changed from the previous version and it does appear . Thank you.

  • Hi Randy.

    can you please check my logs. i have change new pixhawk to my iris+. i see the same problems when switch flight mode. but this time is not fly up to the sky much. only 1 or 2 meter.

    The old pixhawk issue. just when i remove the buzzer then don't see the issue when change flight mode.

    can you explain about this ?

    Thanks you sir !



    • Hi Tri Tran 

      Your problem is the speaker ..I had the same issue on a new build I was doing this last week, on its first flight it would jump up in the air when changing flight modes was the speaker / buzzer that was too close to the onboard sensors and it was upsetting the Accelerometer. The speaker should not be mounted on the top of or on the bottom of the controller board, try to mount it far off to the side or extend the wire. 

    • I'd be interested to see Randy's analysis on this one! It looks very weird to me - your throttle does indeed spike each time you change modes, but your RCIN is constant, so its not you, plus the baro and GPS alt readings are consistent and do not spike. Your IMU AccelZ does spike but it looks to me that this starts right after the throttle spike starts, rather than before - although hard to be sure. The EKF spikes at the same time on all fronts, indicating that there is a big inconsistency between what it seeing sensor-wise and what its calculated.

      I wasn't clear from above - is the buzzer now off? If it's not then I would guess its the same issue.

This reply was deleted.


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