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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      • Randy,

        The last time this occurred it was because of slow loops due to new code. Although not much has changed it is a recompile and some things have changed - I wonder whether this is a timing issue again and whether you need to adjust the loop timings.

  •  Which parameter take the place of INAV_TC_Z in arducopter 3.3


    • Developer


      I think it's EKF_ALT_NOISE.  I personally never change it but I think that's the one.

      Extended Kalman Filter (EKF) — Copter documentation
      • Thanks for confirmation Randy, I searched and finally this morning I found it in other 3d

        I have some problems of altitude loss

  • No, 3.2.1 is the last for APM 2.5/2.6/2.8

    • For copter this is correct that 3.2.1 is the last version that will load on APM, but plane is different. I think AP 3.3 is the last that will load on APM

      • For plane, 3.4 is the last APM release.

        But as this is the copter 3.3.beta thread I didn't think it mattered too much.

  • 3702217713?profile=originalJust updated to 3.3.3 and get "Prearm: inconsistent compasses"  when plugged into my desktop.  Doesn't show up in the few flights I put on, but keeps popping up while reviewing log files.  Is there something to worry about?  The graph is from it's last flight and the prearm clip is currently what's showing up on the desktop currently.3702217669?profile=original

    • Developer

      If it's only happening on the desk then it's most likely just some metal around that's causing interference.  Not sure what version you were on before the upgrade but we haven't changed much regarding the compass in any of the Copter-3.3.x releases.

      • Hi, :)

        we just upgraded two hexacopter from Copter 3.3.2 to 3.3.3 .

        The first connection and flights shows different behaviour than with the former version.

        1* Do we have to re- calibrate the Pixhawk's after this update??

        Also it took very (!) long to make the AUTOTUNE procedure.

        At a landing in manual mode the copter bumps slightly up and down a few times before coming to rest.

        In RTL mode, a copter bounces very hard up and down.

        2* What parameter makes this bouncing happen?

        Another copter suddenly shows compass inconsistency (with disappeared with a compass re- calibration).

        So.................... shoud we re- calibrate all again?

        Thanks for some input regarding this questions :)

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