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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  • Whould it be possible to add a small delay, when Pixhawk is expecting new firmware, before it proceed to wake-up?

    The problem I have is a competition between the laptop recognizing the USB and Pixhawk booting up. Sometimes it requires many attempts to flash new firmware with Mission Planner.
    The stationary, also running Windows 7 Pro 64-bit, recognizes USB quicker and usually manages to flash.

    I guess I'm not the only one having this kind of problem.



    • Developer
      Please keep in mind this discussion is for copter testing.
      Are you using Mission Planner in A virtual machine?
      • No! This happens every time I try to upload new firmware to my copter, or any other Pixhawk.

    • No, your not alone on that. Sometimes I've used the reset button on the Pixhawk to get around this instead of yanking the USB cable out and back in (IIRC) ...

  • Hi Randy and Paul Riseborough.

    I'm testing 3.3RC5 using PIXHAWK and PX4FLOW. And I have 2 question

    1) I have completed all the steps in this guide , but parameter EKF5.meaRng is always 0. In QgroundControl parameter ground_distance changes correctly and is the actual distance to the ground.

    2) I’m set the EKF_GPS_TYPE parameter equal to 3 and trying take-off in Loiter mode. But copter lost YAW control via transmitter and autopilot also cann’t control YAW.

    I read reply zhang xu and all comments but he hadn’t had same problems.


    Help me please with my questions. Thanks in advance

    2015-06-02 14-56-45 2.bin.log

  • Perhaps this has been already mentioned but I haven't seen it.

    Testing 3.3 RC5: The old TRIM_THROTTLE value which i used to copy in THR_MID isn't available in 3.3 RC5.

    The THR_MID stay at 500. Was wondering which parameter replaced TRIM_THROTTLE?

    Thank you in advance.



    • Developer

      Hi Henri,

      We found there was three parameters when their only needed to be one. So to answer you question, Thr_Mid is what you set to your hover throttle.

      • Hi Leonard,

        TRIM_THROTTLE was set by FC, so all we had to do was hover for a while, land and set THR_MID to the value found in TRIM_THROTTLE. Simple, easy. and precise.

        Now we have to look in the logs and approximate the value from the log.

        I miss the old way too.

        • @Leonard: Actually when changing payload it was easy to check if TRIM_THROTTLE had changed a bit or more.. Just a little hover and it was possible to adjust THR_MID.

          Actually it could be done automatically by the FC? (Or is there hidden trap?)


          • Developer

            Hi Henri,

            Sorry I lost your reply. I hadn't thought of that as I am always looking through logs. I would personally be happy with doing it automatically. Randy has been careful and kept fixed. We will probably automate it on the next release after a good amount of testing to make sure it is safe.

            Sorry for the inconvenience. I will talk to Randy about it.

This reply was deleted.


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