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

              Hi Craig,

              I would be very interested to hear how they compare!!!

              Please give me feedback on my FPV racer blog page if you don't mind.


        • Hey Kurt,

          I got my QAV250 tuned on 3.3rc11 with Leonard's help and it flies really well! Before autotune it was really unstable so I recommend that you try this and see how you get on.

  • Am running AC3.3rc11 and have had this issue a few times where what I believe is the internal compass (magnetometer) is fluctuating quickly as if it were under vibration or something....the copter still flies ok but consumes more current and the motors sound strange. you can see on this screenshot and also am attaching the log file from that flight.

    I have redone compass calibration twice and no change, it doesnt do this all the time, only sometimes (like 1 out of 5 flights).....any ideas, could the internal compass be going bad?

    • it just did it again today, always MAG2 on Y and Z axis only, while MAG never shows any problem...also notice how it fixes itself halfway thru the MAG2 the external or the internal compass? 

    • Could it be the other way around? Something in the power train oscillating causing interference in the compass?

      • but why would it only be affecting one of the two compasses? i believe the one affected is the internal compass in the pix but not sure, its kinda confusing to determine which is compass 0 and 1 ....also why would it only do it sometimes and even stop doing it on its own during flight?

        • The internal compass is generally much more affected by interference because it is close to the heavy current loops of the ESC's etc. On my 3DR quad the internal compass has lots of interference, the external compass (on a pole), pretty much zero.

          • Which is precisely why I think you should be able to disable the internal.. maybe you can now and I missed that? I have often gotten the compass's inconsistent warning. Seems like if I could turn the internal off it would be beneficial. There's no failover for added safety anyway that I'm aware of. 

            • +1 - I also would like to have an option to disable the internal compass. I believe it would be beneficial to the system.

              • i think there is an option to disable each compass....but which one is MAG2? I find it difficult to tell if thats internal or external

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