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,

              Any advice setting up the Z1 Tiny 2 in APM Mission Planner?  What gimbal type do you select?  (I assumed servo since that's the type of input that the tiny 2 would accept from a normal receiver).  For whatever reason when I try to connect the input pins for the Z1 Tiny 2 to my Autopilot (driven by ppm from receiver) it just buzzes and doesn't care about what inputs I'm giving from my radio.  If plug it in directly to the receiver it behaves like it should (slews to where I have my radio set to).  

              Thanks in advance,


              • Hi Fnoop and or Jeremy,

                Did you have any result allready on the setting for the Tiny2?

                I'm looking everywhere to find something about the wiring from my PixHawk to the Tiny2, but didn't find anything usefull yet :-(.

          • Well I have a 3 axis brushless. Elev and azim are on pass throughs from pixhawk. Elev can be controlled by pixhawk too.
    • Only if you have a brushless gimbal controller between the brushless motors and the APM.

  • hi, is it possible to connect a brushless gimbal (not servo!) to my APM?

    thanks for any help.

  • I reflashed all my ESC's (RCTimer 16A) to BLHeli 14.1 with damped-light, medium high from SimonK and now I get a serious wobble/vibration in flight. Is this just a case of needing to run autotune again or should I be looking for something else? This is a QAV250 setup. If it needs retuning what should I change manually to get it to a more stable place where I can confidently run autotune?

    • Developer

      Hi Andy,

      The motor breaking probably means you need lower Rate gains. I would say drop your rate gains until you don't get oscillation then do autotune again.

      • Hi Leonard,

        Can you tell me which setting this is?


        • Developer

          Hi Andy,

          Drop Rate P, I and D for roll pitch and yaw by 25% at a time until you stop oscillating. And make sure Stab P is about 5.

          I am assuming your wobbling is fast and not slow....

          • Hi Leonard,

            Thanks that was it - amazingly I had to drop them about 75% to get a stable hover again.

            It was a fast rotating wobble, a bit like a spinning top just before it falls over.

            Is this because the motors are more responsive now or something else?

            I've read to the end of the RCTimer 20A thread and it seems a lot of folk are unhappy, but these have flown fine on SimonK for a while now.

This reply was deleted.


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Aug 25