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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          • @Fnoop thanks for education. I am using FollowMe since its introduction extensively in my DIY stuff and with Solo, and know how it works.
            Call it whatever you like, but having the drone speeding away when you hit Pause is not what you want.

            @Randy thanks for having a look, if you need more data let me know.
            Here is a short video about the incident
            • Developer

              Stephan (sorry for the incorrect spelling before),

                   I've recreated the problem very easily and I'm digging into the cause but I haven't figured it out quite yet.  I'm not even sure yet if it's in Tower or Copter.  I'm going to be off this afternoon and tomorrow so unfortunately this bug is going to survive another 48h but it's top priority so it won't make it 'till monday I predict.

                   Thanks for reporting this!

              • Thank you Randy for looking into this.
                Please take all the time you need.

                Btw it worked perfectly well with 3.2 and also no issues with Tower along with Solo.
                A recent change on my end was to add a LidarLite via PWM.
                warm regards
                • Developer

                  I'm pretty certain the bug is within Tower and not Ardupilot.  I've created an issue for Tower here and although I haven't been able to again recreate the issue exactly, I've been able to make the Pause button cause the vehicle to fly off if I first make the vehicle report a bad GPS position.

                  Pause button causes Copter-3.3.2 to fly off · Issue #1695 · DroidPlanner/Tower
                  I&#39;ve reproduced this problem just now after being reported by Stephan on the Copter-3.3-beta testing thread. I&#39;m looking into the cause as a…
                  • Randy, please find the tlog file attached. 

                    Let me know if you have any further questions 

                    Best Stephan 


                • Developer


                  Strangely, although I produced the problem once very easily, I've been unable to reproduce it again despite hours of trying.  Also we do not record the commands received from Tower in the dataflash logs (I will add them) so I cannot see if it's caused by Tower or ardupilot.

                  Could you try and find the .tlogs from Tower from this incident?  I tried myself but there were no logs recorded on my tablet.

                  The logs can be found by connecting the tablet to you computer, then (if you're using Windows) go to the file manager and look for the tablet's name.  open that up and under ../Android/data/ you should see a bunch of tlog files dates in the filename.

            • Developer


              I didn't get to this today but tomorrow for sure!

            • I wasn't trying to lecture you, just point out the fault might be with Tower not APM and it's not uncommon to hit glitches in the more complex modes.  Hopefully Randy can narrow it down from the log.

  • Ran into a strange defect with AC 3.3.2 and Tower latest release today. Was my fist set of flights in FollowMe with 3.3.2

    1. Fly in Guided (Follow Me)

    2. Press pause, the copter will accelerate immediately and fly off, can only be saved by switching into another flight mode via RC control - Loiter in my attached log.

    The defect is fully reproducible, I tested this twice in 2 separate flights after a power cycle in between.

    Very annoying and dangerous. W/o the RC transmitter in my hands the drone would have gone straight off and crashed somewhere. Log file attached.

    • Developer

      Thanks for the report.  I don't see your log file attached..

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