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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    • Just to give a hint, i take off in EKF error, LED is flashing yellow/Red not blue as usual.

      • I didn´t watch the LED when taking off, but in the log there is an EKF_CHECK Error. Normally this error is cleared after a few seconds, but without GPS it remains.

        • Developer

          Ok thanks.  So this is an item to fix!  We need to think of a way to not trigger the EKF failsafe in cases where the pilot isn't using a GPS at all.... perhaps we should only enable the EKF check after the EKF has initialised it's position estimate.  Issue raised here.

        • ok don't seen the log. did you just hover or flown around ?

          To explain the error, it is like you are giving a short roll input and then it's remaining on this angle not going back to level, like it's assuming this is level.

          Roll and Pitch feels inconfident.

          • Flew around a few meters to test roll & pitch response - copter always returns to perfect level.

    • With GPS (3dr ublox) detached i get bad compass health - no readings from external compass - perhaps powerd by serial port of GPS. Switched off GPS in params - no change in flight behaviour in stab and alt hold. Perhaps problem is caused by compass autodec (wrong or changing without GPS-Position)?

      2015-07-14 07-58-04
      • Developer


        great, thanks for testing!  It does appear to be flying fine.

        I totally forgot that the compass is powered from the GPS's 6-pin UART cable so if that's detached it won't have a compass anymore.  One way to disable the GPS in software only is to set GPS_TYPE to "0".  That'll basically turn off the software driver for the GPS which is good enough.

        • Randy,

          that´s what I did as you can see in param GPS_TYPE.

          The copter flies exactly like it does with GPS (and so EKF also) switched on - of course GPS-using flight modes don´t work.

          Many thanks for your great software!


  • I have an odd problem after loading rc7.   I have a quad with a QAV550 frame, has 12 inch props, runs 6S with 380KV Tmotor's and have never gotten it to fly with a solid stability. If there is no wind, it flew pretty good, but I have been waiting for no wind to do an auto tune.  I updated the firmware from rc5 directly to rc7 over the weekend and now it is practically unflyable.   (I seems to have no stability at all in stable mode.

    I will include 2 flash logs.. the first is after flashing the firmware to the 3.3rc7 and no changes except for these settings: 


    I doubt that is my problem, because subsequently I reset the board to defaults and redid all the calibrations and setup, and when I tried to do a test flight, i was just as before, unflyable.. To define unflyable, I really couldn't get off the ground because it was determined to pitch forward, or back on its back. Both attempts, (before the reset, and then there flight several hours later after re configuring)  ended in the copter flipping onto its back.  

    All the motors are spinning the right way and the props are on correctly.  It is as if I am trying to fly with no gyro, or accelerometers . I will attach the logs.  The 13.bin is the first flight on 3.3rc7 and the second 15.bin one is after I reset to defaults and redid my setup leaving the PIDS at factory.

    More about the copter:   It weighs 96 ounces 2.72 kg.   I'm set up for fpv with a go pro feeding video for FPV using 1.258MHZ. I am using a tarot gimble and of course the 3DR PIXhawk, early version.  I and using EZUhf on 433 with diversity, Taranis and using 915mhz 3DR radios for telem and a minumOSD,  I love the way it works when it is working! 

    Any help figuring this out would be fantastic! 



    • Developer

      Thanks for testing with AC3.2.1 'cuz that shows that it's really a general setup issue rather than AC3.3 related.

      It looks like some kind of mechanical issue to me although it's hard to say what the issue is.  Maybe an issue with the back left motor or esc but it could be ESC calibration is required, one motor is not starting, a connection to an ESC is broken, prop or motor spinning backwards.

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