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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  • hi randy and all friend.

    My hexa is problem with speed up when  i push little thorttle up or down with YAW, then my drone speed up or down very fast, just alittle about 30cm.

    My drone : 3DR pixhawk, 3dr gps lea6. KDE motor 475kv, esc 35A+. props 14.5, battery 6s 6.000mah, total weight almost 4kg.

    ffrimware 3.3.3 i have try with autotune 3-4times but the pid look bad. can't fly with that pid. i have manual setup and it's look good abit, but with the post hold mode, when i push pitch or scroll and stop then my drone is oscillate, not smooth, but with loiter mode or alt hold work good.

    Please give me an idea. Thanks all

    this pids after autotune.


    • Pids are not bad, but stabilize pitch/roll params are usually not more 8. You can try manually 5; 6; 7 etc.

      The reason for Yaw and throttle height variations is bad barometer ventilation. .Will be good to send picture of the copter and the Pixhawk position.

      It is important to make the barometer damping with dense polyurethane, proposed by Marco and I posted here:

      Then should avoid the air stream from the propellers direct to the controller - can try kind of windshield, box with some side holes only or similar. When launching / landing the air pressure area below the copter can cause jumping, if barometer not damped.

  • I am so pumped for 3.4......

  • Is it possible that the latest firmware reports things like "bad gyro health" more often?  Sounds funny, but I've been getting this message sometimes during flight or just hooked up to the computer making param changes.  No effect of flying so far.  I had two previous Pixhacks with this error, but they didn't clear and had to be returned.  One of the Pixhawks actually crashed.  I was under the impression it was definitely a hardware issue.  Should this autopilot be retired?  The message has shown up 3 times this week.

    • Developer

      That error can appear for a few reasons so it's hard to be sure but if it only appears soon after startup then I wouldn't worry too much.  If it's appearing in flight then I would worry and would probably replace the board.  Looking at a dataflash log and checking the IMU messages's final two fields (AccHl, GyrHl I think) which have the accelerometer and gyro health would be good.  If it's changing between healthy and unhealthy or one of them is always unhealthy then it's most likely a hardware issue.

      • I'm a bit confused lol.  Do you mean AcHlt and GyHlt?  If that's the one, I'm getting a drop from 1 to 0 on GyHlt from IMU2 every few flights.  Also, anyone know what this "ERR: 195-129" is?  


        • Can't remember where I heard it or if its true, but something about the gyro does an internal calibration on power up and if the copter gets jostled during this time (like plugging in a xt60 main battery connector) it can throw this error. This would be different than the flashing red/blue partway through the pixhawk boot. Again not sure if accurate, maybe someone with the hardware knowledge can chime in.

        • Black Sheep (who I bought the pixhack from) says it interference...  Really?  Not the best answer.

      • ok, thanks for your comment :)

        Is it enough to have the LOG_BITMAPS = 958 to see that later in the dataflash log? (Pixhawk)

    • Hi,

      I can confirm this. (often the bad gyro health 'report')

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