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

      Bill, can you please post the log file with your test.  None of us have actually tested it in a mission so it is quite possible it does not work.

  • I was pretty excited to try the new autotune in 3.3rc3 with yaw, but what I got was strange.  My Rate Roll was .32 .93 .021 and Pitch Rate was .28 .71 and .02.  Make for a really shaky flight.  Before I was at RR .25 .1 and .004 which seemed to fly fine.  Strange thing is I found that autotune in 3.2 would match the P and I values and now the I values are way higher than the P's.  I've heard from others the I value should be lower than the P.  The yaw seems pretty good, aggressive but works well.



    Tarot T960

    Foxtech 5101 motors

    DYS40a esc

    18" props

    6s22,000 battery


  • There seems to be a problem with auto analysis of logs produced by 3.3 in MP. I get errors saying "NSats" and then "Bad input file" and no auto analysis. 3.2.1 is fine. I put an issue here


  • Thanks for the all the work with the updates.

    I just loaded RC4 and now getting a Bad Gyro Health warning on mission planner. RC3 worked fine.

    Any suggestions?

    • Me too...on both multi with original Pix I have...gps is 20 cm or so away...

      "Read the ublox binary format specification and learn how to find and interpret the noise, jamming indicator, and agc values in the UBX1, UBX2, UBX3 messages as well as the estimated position and velocity errors reported in the log"....?????

      I didn't know we all have to be experts in gps electoronics to be able to fly our multirotors

    • When did you buy your pixhawk?

    • I was getting bad gyro health yesterday as well.  Not there today.  Stange.

      • When did you buy your pixhawk?

        You could try my patch to see if you get these in flight:

        If you want I could put up a build of rc4 with this in.

        • I believe this Pidhawk is about a year old.  I've got so many it's hard to keep track lol.  I presume this patch is added to record GyrHlt and AccHlt under the IMU section...  Yea, I have no idea lol!  Just have to learn how to add a patch of code the the current build.

          • It would be a good data point to know which IMU is failing. For me it is IMU2 which I believe is the lsm303d which makes no sense to me, since re-reading the "Bad Accel" thread it's clear that the MPU6K is the culprit and lsm303d issues only occur on non-3DR boards. Is yours a genuine 3DR pixhawk? Could it have been purchased in July 2014 (I know that's a bit less than a year, but that was the start date of the bad batch).

            Maybe this is just software, but it is something since there are three of us (at least) with this issue.


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