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

      Hi Pomaroli,

      Looks good to me. I can't see anything that makes me worry about it. And if it flies well, that is the acid test. Enjoy!!

      • Leonard, yes it's pure fun. Next step should be to make pixhawk full 3D, (motor inversion)

        Did you see on the beginning there is the EKF error, is this normal or do i do something wrong ?

        Shall i try the new parameters ? What do you would recommand for 4s high performance ?


        • Developer

          Yeh, I saw that.

          That is pretty normal. 

          For 4s I would use

          MOT_THST_BAT_MAX 16.8
          MOT_THST_BAT_MIN 14
          MOT_THST_EXPO 0.65
          MOT_THST_MAX 0.95

          You will probably need to auto tune again after changing these parameters though.

          • normally i set battery low to 13.5V to gain enough Flight time.

            Is it important or shall i leave MOT_THST_BAT_MIN = 14 ?

            • Developer

              Hi Pomaroli, this is just for the throttle curve. It doesn't effect flight time or battery fail-safe. 

  • So... what has changed in 3.3-rc7 for tricopters?

    Had a reasonably well-flying RCExplorer V3 with 3.3-rc5. Updated to 3.3-rc7 this morning and now I have a whirling ball of death with a broken battery plate. Response of the servo to being picked up and yawed by hand seems to be excruciatingly slow (like, takes maybe five seconds for the servo to go hard over). PIDs have been changed since I reset to default but it used to be flyable with default settings (it wasn't pretty, but it also didn't approximate the Tasmanian Devil).

    While troubleshooting, I reset to defaults. That didn't change anything. Nor did switching RC7 to reverse. Nor did switching the yaw servo to output 3 (I know Rob had been talking about making that change not too long ago).

    I don't see anything in the changelog. Maybe I missed something in the 165 pages of discussion? It's getting to be a miserable pain to fish through that. Anyone have any thoughts?

    • Hello SwissFreek,

      I'm not completely sure what the issue is, but I noticed the same thing back in 3.3-rc5. It has something to do with ATC_ACCEL_Y_MAX.  leonardthall reviewed my log and found this setting to be at 9000 and suggested setting it to 27000. That did the trick. (the discussion was back on page 107) I recently settled on 40000 and the yaw is very crisp to my liking.

      But there is still a problem as when you run a Yaw autontune, it will default back to 9000. You'll have to go in enter the value you like.

      • I don't think that's my issue. GCS says my ATC_ACCEL_Y_MAX is 27000. When I said my tail was sluggish, I just meant when I was wagging the tail by hand (with the props off and motors spooled up so the yaw correction kicks in) to confirm that the tail servo was actually working, not in flight. In "flight" I now have zero yaw control, and as soon as the copter leaves the ground it goes into a high-rate flat spin, and there's nothing I can do to stop it besides slam it back into the ground.

  • RTL via GCS in 3.3 RC7

    When finished  auto-mission with the copter hovering at the last waypoint I can´t switch to RTL via GCS (Tower) - i have to use the RC.

    I´m quite sure it has been possible in 3.2.1 and in the first RCs of 3.3 even with flightmode auto still switched on on the RC.

    Also after finishing the auto-mission gimbal control with RC channel is switched off - i use it to turn the lens of the camera upwards to protect it from damage during land.

    Is this the correct behaviour or is it a bug? - providing logs is only possible via cloud because of size so I have to upload the .bin to dropbox what takes about an hour or two with my slow connection.

  • As I received all replacement parts after the rc6 crash I did a few runs today with rc7. No rc6 problem (but it happened only during the 3rd battery last time) so fingers crossed.

    Generally very smooth experience with some comments:

     - with strong wind loiter position hold was very nice; however position hold mode correction was absolutely different - very twitchy and nervous;(my PID from rc6 tuning)

    - switching from loiter to pos hold resulted in climb ... it was my feeling/POV but could not find it in the logs

    - I had the strange feeling that in loiter I could manage the quad orientation in FPV very well, but in position hold it arrived siding or even with wrong yaw.


    video log1

    video log3

    Furthermore - minimOSD/mavlink info so strange ("disarmed"; speed info etc.) that dont even check on the 2nd video.

This reply was deleted.


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