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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    • It will be nice once the Wiki catches up on all these changes. Just a shot in the dark here but what is your MOT_THST_MAX set at? Mine is 0.95.

      • Same, 0.95.
  • When upgrading from 3.3.1 to 3.3.2, is it necessary to recalibrate the accelerometers and compass or are the previous calibrations maintained?

    Thank you


    • I didn't do it.

      • Thank yo for your reply Cala

  • I make a little test because of high wind today.

    To reproduce the issue on my copter I take off in stab, , switch to pos hold, land, switch to stab, take off again in stab, try to hover in stab, switch to pos hold (there I loose altitude after update) and now works well, if the copter was climbing in stab and switch to pos hold, after update, there, he didn't do the issue. Thank's Randy to solve, tomorrow  better forecast I try again larger time.

  • I loaded up 3.3.2-rc2 on my QAV250 and flew a little in stab, poshold and althold in pretty windy conditions. All seemed well. Switching from stab to poshold and back again at hover throttle didn't result in any noticeable drop - seemed to work just fine. Wind holding was ok, somehwat limited by the accuraccy of my GPS. So thumbs-up from me.

    • Just an update. Seeing lots of "accelerometers not healthy" errors. Used to get these occasionally now all the time. If I set INS_USE1=0 does that stop the pre-arm checks on the 2nd IMU?

      Also what's going on here? Logs attached. clip0/clip1 have step changes. What would explain this? Are these values cumulative now?


      • if you are getting a lot of clipping then your vibs are too high and a lot of people are reporting it is because the bells on their motors have too much slop and removing the slop has worked wonders for them. I had the same issue on a hex with brand new motors. I've since sold off that hex and built a T960 and it no longer has the issue with the same flight controller :) Seems extreme lol but I was going to sell it anyway. The new frame and AVmount producrs nearly 0 vibs and 0 clipping.

        • No its not that. Here is a log from earlier, same copter, earlier FW. Vibes are about the same, but zero clip.

          And clip doesn't go up and stay there - look at the graph you will see what I mean. Something strange going on.


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