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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  • found an issue here. I did a hover test a while ago. Then I download the logs, performed a review on the logs to check on the vibrations etc. Then I tried doing an AUTO ANALYSIS. But something went wrong, here's the screen cap. I am using RC5 and the latest beta firmware of Mission Planner. Note that the HUD also states the EKF  PRED POS HORIZ ABS error.


    • Moderator

      There is a new release for MP (1.3.28) that fixes this issue. I had the same issue and the new release fixed it. The Auto Analysis issue that is.


      Nathaniel ~KD2DEY

    • I got the same error, probobly rc5? But it is a rc so maybee not suprising.

    • I tried clearing the logs and did another test flight. The same error occurs when doing autotune. It seems that this is a Mission Planner error though, not Arducopter error. 

  • I have been having one small issue ever since 3.3 RC-1. I have yet to see a landing detector disarm. I have been landing in loiter mostly. I just go to stabilize and disarm. I remember it working before with 3.2.

    I am also getting the vert ekf error, but the bad ahrs warning went away with rc5. Will test rc5 shortly. Yesteday was  rc4.

  • I am very much convinced at least one EKF error is a result of the recently updated MP. My large Y6 which is on r3 had zero errors after many flights. Today I connected to MP and right away a EKF error pops up.


  • I was recently flying my quad with 3.3 RC3 and it suddenly flipped into the ground. I have attached the log. I ran the auto analysis and it failed the brown out test. I never had this issue prior to the 3.3 update.

    Here is the log.

    Any help to determine the failure would be appreciated so that i might avoid this is the future.

    It is using a PixHawk with 3DR Power Module



    2015-05-12 18-38-29.bin

    2015-05-12 18-38-29.log

    • Developer

      Hi UAS_Pilot,

      I can confirm looking at the logs that the autopilot wasn't running when you crashed. It looks like you lost power to the pixhawk.

      Sorry about your crash!!

      • All connections were good on the airframe. Not sure why the brownout. I will be rebuilding it. I don't think vibration caused any issues, during this flight I was flying pretty hard whil in stabilize mode.

        Thanks for the information I will look over the system really good during the rebuild.
        • UAS_Pilot,

          From the log it looks like you didn't have a brown out, you had a black out! That makes the fault tree look pretty simple:

          1. The BEC on the power module failed (a second BEC connected to the servo rail will protect against this)

          2. The connection from the power module to the Pixhawk failed (loose connection, bad solder joint, wire on the connector not making good contact, e.g., bad crimping).

          3. The connection between the power module and the battery failed (bad solder joint, loose connector).

          4. Internal fault in the battery

          Good luck.

This reply was deleted.


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