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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        • Randy didn't mention it in the release notes, but my PR for this bug was merged and is included in AC3.3rc9 so automatic flow control should be working again now.


        • Randy,

          I had suspected this was a 3.3 only bug and Mark's experience seems to confirm that.

          I'm guessing some timing changes exposed this latent race condition sometime in the 3.3 rc series.  In any case, I'd consider it a regression and perhaps you will want to review this PR prior to the 3.3 release.



    • Probably not helpful, but my radio telemetry works fine on rc8.

      It's working on telem1 as well as telem2.

      Do you have something else connected in parallel with the telemetry radio with an Y cable?

    • I´ve the teensy working with -rc8

  • Hello Folks,

    since -rc8 was released I´m using it. I´m flying every Day min. 1h. No faults every thing worked very good.

    Only on thing does not response is the "DO_CHANGE_SPEED" command. Just nothing happens! But I´ve to say that I´m using ch6 to change the WP_Speed. My thought is the the DO_CHANGE_SPEED command overrides the WP_Speed and if a new WP_SPEED comes from ch6 it overrides the previus command.

    I would appreciate a "condition_change_speed" AND a "condition_change_VS" (VS=vertical_speed).

    • Developer


      Yes, as you suspect using ch6 to "tune" the wp-speed will overwrite the do-change-speed command.

      There are a couple of to-do items (here, here) on the issues list to allow setting the speed-up/dn but just haven't gotten to it yet.

  • Hi

    My pixhawk accel calibrates fine on 3.2 but refuses on 3.3rc8.  Could this be linked to the acceleration sensitivity being increased?



    • Anyone able to advise on this?

  • Just thought I'd give a shout out to the Dev's of 3.3!  A solid day (so freakin' tired!) of mapping for contours and volumetrics.  My mapping X8 is solid as a rock.  25kph winds and going strait as an arrow.  Still a few issues with the geotagging, but not a bit problem using Pix4d and a 90 degree kappa adjustment.  Best flying mapping drone yet.

  • I have not been able to download log files via Mavlink or even terminal IIRC since day one on PIxhawk. It always pops up "Error receiving log list". I have gotten so used to pulling the sd card out and getting the logs it kind of became normal. Would erasing the sd card and reloading the firmware fix it? 

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Aug 25