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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          • was it your 1st autotune try? did you change anything else?

            do you have a short log with stabilize and a poshold?

            i don´t see my problem optical....only in log and fpv cam


  • Dear Randy

    Please help me
    I have change new pixhawk to my iris+ and setup fw 3.3.1 and calibration all. What is happening now is that Altitude Hold and Loiter are unable to maintain a consistent altitude. When I keep the iris+ hovering in place (either by manually doing so or using loiter), I get an altitude change of +/-1-2 Meters or more 10-20meter. This is a bit of an issue but even more so is that when I fly it laterally, it loses altitude quickly when i switch loiter to alt hold and all of a sudden pitches/rolls violently then shoots up into the sky where I have to quickly change over loiter and back to land.

    thanks you so much !

    here is logs file.

  • Help!!
    I have Compass problems, calibrated OK but high offset on internal Compass. Have I done something wrong during config?
    As soon as I yaw I get EKF Compass errors it looks like MagY sometimes follows and sometimes mirrors?
    When I fly, land and disarm. and then try to arm and fly again I am not allowed due to EKF Compass errors.

    Should I try to disable the internal Compass?

    2015-11-12 14-06-59.bin

    • I disabled int compass and all works well now

  • hi, i have run into this issue that happens sometimes but only seen it in 3.3.x releases, where pix will not enter into a flight mode that requires GPS, but the GPS are ok (i have 2 of them), all I have to do is restart the pix and then it will work fine....log attached of the issue from today....I took off in manual, went to enter loiter or auto, neither would take giving flight mode error....but far as I can see both GPS seem to be working fine....any clues?

    2015-11-09 14-27-46.bin
    • The last recommendation I recall was to use one GPS until 3.4 addresses issues related to 2x GPS. Is that not correct?

      • Developer

        Yes, as DG says, the recommendation is not to use two GPSs until Copter-3.4 because of the jump if it switches the primary GPS.  Master's has about 1/2 the fix already so hopefully the full solution will be in Copter-3.4.

        • Hi I used to have two 3dr gps but it kept jumping say a couple of meters so I fitted a m8n which gets between 16 and 18 sats so there is no jump as the 3dr only gets 11 at most but should the m8n fail it hopefully will switch to the 3dr one and at that point I figure a jump would be better than no gps
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