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!

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


      • Thanks, it definitely does it without the motors being powered.. I can rotate it in my hand and it does it. 
        But, it's really random.  I'm doing it now.   Powered up, only about a pixel of green showing at the bottom of the EKF compass meter.  I rotated it 180deg, and it went all orange.  It slowly dropped back into the green over a minute or so.  Now I'm rotating it around in the exact same spot, and it's staying in the bottom 1/2 of the green. 

        Well, I'm not asking for help, so I'll drop the subject.. I just wanted to mention it, in case it was an issue or other people were having the same thing happen. 

        • The issue you methioned happens here with My Autopilot, with Copter V3.3.2, the EKF status of compass just goes red on my desk when I just rotate the autopilot by 90degrees.

          Have you resolved this issue yet?

          • Make sure you have your compass orientation set properly. At some point in AC releasese devs changed default compass orientations, so what it usd to be roll_180 now is orientation_none. 

        • With good calibration I cannot get it above 0.5 even when turning it quickly. If it happens when you turn it slowly then something is up - either calibration or local interference. Hard iron and computers are bad - but you only have to be a meter away or so for this not to matter much.

          What FC do you have, have you run compass mot?

        • Are you doing this indoors anywhere near say a PC or speakers or anything else large and metallic?

          Does it do so outside when you're not around anything such as a car or anything else metallic?

          • It does it when I'm up in the air, so it's not a metal object causing it. 
            I have done a compass mot, and I have recalibrated several times. 
            It's an auav-x2, with external gps/compass (currently, csgshop).

            But, sounds like others aren't having the same issue.  So like I said, I'll stop talking about it here in the beta section. 

            I probably just need to drive somewhere else to calibrate..  Every room in my house has speakers. (I build hi-fi amps as another hobby.)  My yard has metal sheds and porches.  Mostly aluminum, but some iron poles. 

            Sounds like these could be causing some calibration issues.

            Thanks Andy and Craig.

            • Make sure you don't have the problem I had - AUAV-X2 + ACPS3 give spurious current readings when the battery is not connected. This means that the MOT offsets will be applied even though there is no interference - leading to a very unhappy EKF when on USB power. Try setting COMPASS_MOTCT to 0 just to check.

  • Hi,

    I have a problem with the beta firmware on a VR μBrain 5.1

    when I try to put the new firmware 3.3-rc12 on the VR μBrain it shows in mission planer as 3.3-rc8.
    Anyone else with a VR μBrain come across this ?

  • I have tried 3.4 dev (master) and i have problems with compass calibration on Raspilot v1.1

    i have a external compass connected as well as the internal (s).

    Anyone else using Raspilot ?

  • I don't know if this is a Pixhawk problem or build problem but I can not get an acceptable compass calibration. I have done just about every method even spinning in an office chair. At the end of 20 minutes of spinning and 1700 data points I still end up with compass 1 with -931 613 -2655536 and compass 2  314 -195 -44 After restart I still have a double flashing yellow on the pixhawk, error compass variance in MP and a red EKF for compass on the HUD. This is with RC12 and the latest version of Mission Planner on a 2104 3DR quad frame and PDB with a M8N GPS/Compass from Ebay on a 6in extender.

    Any suggestions or will have have to keep playing spin the chair with my son? He for one enjoys it.  

This reply was deleted.


David Hori liked Isabella Domi's profile
Jan 12