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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  • hi all. please help.

    i just build new quad 250 pixhawk and tx gx7 JR, i can fly good with mode stabilze but i can't control and take off or control with alt hold mode. because the mode alt hold only work with thorttle, picth and roll and yaw not working.

    can someone help me fix this ?

    • Better if you can share

      • a log, easier to help

  • I'm using copter v3.3.3 on a tricopter as shown in the diagram below. My yaw servo is plugged into a Pixhawk main out 7.

    I don't seem to have any control of the yaw servo when the safety switch is armed or when the tricopter is armed. Should I expect the transmitter yaw stick to control this servo on the tail motor? Are there any settings I may have missed to select a tricopter other than when downloading the firmware?

    Thank you...


    • as Hubertus mentioned only FC controls that servos, try raising throttle to about 20% aand you'll be able to. 

      also, there are a few settings to set for proper yaw control on a tricopter, otherwise it will be "laggy".

      ATC_RAT_YAW_FILT = 20 
      ATC_SLEW_YAW = 18000 
      ATC_Y_MAX = 100000 

      these are for ac3.4, so to find them in ac3.3 just omit the "ATC" part.

      if you encounter "wagging tail" try lowering yaw_stab and yaw PIDs. D needs to be 0 for the "manual like" yaw control, otherwise AC controls yaw too much and it gets slow... 

      • Ok, thank you for the suggestions guys. I forgot to mention that I have a 5v regulator plugged into Pixhawk main out 8 and the motors 1, 2, and 4 are opto ESCs that all work fine. The yaw servo seems to be energized but I wasn't sure about the APM operation. Based upon your suggestions, it may be the laggy feel I am experiencing.

        This is my first tricopter, which is also a tilt wing, called a CL-84 from Hobby King. I flew it fine using SimonK ESCs and the stock controller allowed for yaw stick to move the yaw servo. While I wait for Tridge to make some special tilt rotor code for the CL-84 transition servo, I thought it would be cool to try Arducopter v3.3.3 and have it hover in place like a real autonomous vehicle. We'll see what happens...

        • You guys were correct. I re-tested and I do have yaw control, but it is real sluggish. I found the RATE_YAW_FILT parameter and changed it from 5 to 20. However, the other two parameters elude me. Could the names be different in v3.3.3?

          RAT_YAW_FILT = 20 
          SLEW_YAW = 18000 
          Y_MAX = 100000

          • try searching for "slew" and something related to acceleration over Y axes. 

            setting those will give you the "manual" like yaw control. 

            also, it helps to properly set servo endpoints to something like 1100-1900, defaults are really minimal. 

            do not forget your servo midpoint, i find that setting it slightly off center to counter natural yaw helps, but since it is a "plane" not sure how it will affect the fixed wing mode. 

            • That's much better. I found the params in v3.3.3 as follows and set them to your values. I have yaw control now. Thanks for the tips!

              RATE_YAW_FILT = 20 
              ATC_SLEW_YAW = 18000 
              ATC_ACCEL_Y_MAX = 100000

              • My CL-84 VTOL is hovering quite nicely in some wind now after adjusting some PIDs. This was just a test while I wait for Tridge to release some new Arduplane code for the CL-84 tiltwing. I also updated my Tarot 680 Pro hexacopter from Copter v3.1.4 to v3.3.3 and after re-calibrating the ACCs and GPS, it flies perfectly!


                CL84 with APM Copter Test 2 from Gregory Covey on Vimeo.

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