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

        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
          • yes I have M8N and 6M, and the M8N is always lower HDOP , but i have had then switch in flight with no issue, seems to work ok for me in that regard and i have tested it too (by disconnecting the TX wire from GPS into Pix via a relay switch)....but i dont think the issue am having here is related to having 2 GPS necessarily...

  • Hi I have a quad done auto tune flies great with 3.3.1
    When in drift mode it can reach 50mph but is OK up to 30/35 mph but above that it starts to dive loosing height tried changing max angle for all flight modes to 30' but still losses hight above 35mph
    could this be software or does any one think frame/mechanic have reached its limit on forward speed and power to keep nose up enough to maintain hight
    It's not a barometer problem as I cover whole pixhawk in cling film to keep out wind altering pressure on barometer
    • Developer

      Hi stubugs,

      Can you provide a log please.

      • Hi did you manage to look at my log
      • hi please find attached log

        many thanks stuart

        2015-11-08 13-28-14.tlog
        • Developer

          Hi stubugs,

          Sorry, I need a data flash log.

        • Nice setup but it looks like you push the quad speed envelop to hard. Theoretical max propeller air speed with lowest measured bat voltage approx. 13.6V with 390kV motors and 5.5 inch prop is approx. 12.3m/s. To be able to move air faster increase voltage or change motors and propellers

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Aug 25