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


          I think mission planner is always reporting the status of the first GPS on the HUD instead of the primary GPS.  Ardupilot should report which GPS is primary so MP but it doesn't yet.

          • Hi Randy. Something related to this? In MP you can see the MagField for the compass being used by the FC. But what about the other one? Is there a way to read it? Maybe APM PLanner or Tower can show them?

      • I've been noticing something similar with -rc10 and the tower app. When I power up and connect tower will read NOFIX, then after the usual time it will annouce '3D lock', then I arm and take of and a minute or so later it will say "no 3d lock" even though it still has 12 sats and HDOP of 1.2 or less. The copter still flies ok in gps modes (Not great but it is never great... I have some tuning to do)

        • As far as I'm aware, it's because there's a new fix type of 4 which indicates a sbas fix. The old version of tower doesn't know this yet, so when your fix type goes from 3 to 4, tower says no 3d lock, but it will fly fine as the lock is better than a 3d lock.

          • Ahh great thanks Glenn and Randy, that will give me some more confidence when i'm in flight and my phone announces "Lost 3D Lock". :)

          • Developer

            Yes, Glenn's right I think.  I've raised an issue with the Tower guys here.

            Ensure Copter-3.3 GPS status 4 is processed · Issue #1588 · DroidPlanner/Tower
            recent ardupilot versions including Copter-3.3-rc10 will report a GPS status of "4" when they have both 3D fix + SBAS. Tower may currently be crying…
          • That’s some killer orientation skills when it knows where it is on a 4 dimension basis in a 3 dimensional world! 3.3’s getting better all the time! :]

        • I just had some thing weird happen with the Tower app ( not resently updated). I changed the mid throttle from 600 to 450 through the app, ( changed props from 13 to 15in) when I tried to take off  I forgot to push the arm button on the quad, but attempted to arm from the controller.

          I got the normal arming tone even though the  motors did not arm. I am use to getting the arm failure tone when I make this mistake.

          I pushed the arm button on the quad but got no conformation tone. The motors stopped pulsing and beeping so I armed the quad with the controller. In AltHld I raised the throttle above the dead band and the quad shot in to the air and I pulled the throttle to minimum and the quad stopped about 30ft up.

          With throttle at minimum the quad was barely desending taking 2 mins to decend from 30ft. I had control of roll and pitch and yaw. Thankfully I got it back on the ground safely and disarmed normally.

          The log from that flight would not download.

          • Get it from the SD card directly. Would be interesting to take a look at that. 

    • If I remember correctly dev explained that they use overall health of the GPS coords which include GPS accelerations (can be mistaking here) but the error messages is still generic GPS fix for all GPS problems... M8Ns are usually the ones having such issues as they are waay too sensitive and pickup EM noise from the copter. 

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