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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      • I don't know if this helps, but whenever I plug in the USB and also have the flight battery hooked up, the USB voltage is added to the flight pack voltage. so whatever voltage is showing, say 21v for example, as soon as the USB is hot from the PC the voltage display goes up about 4v.  Unplugging USB the pack voltage goes back to normal correct reading.

        so whenever i am calibrating pack voltage reading and making adjustments, I do it via 3DR telemetry to MP.

    • Developer

      Hi Joe,

      Could you add some photos of your test setup and some details on how you are doing your reference measurement.


      • Not too much to show.  I am measuring at the power module input solder points.  Using a multimeter to measure voltage.  The power module is mounted in a copter.  Components are stock 3DR with exception of the power module BEC not being used.  

  • hi, is it possible to connect a brushless gimbal (not servo!) to my APM?

    thanks for any help.

    • answer is yes and no ! only Storm32 BGC supports the Pixhawk can be connected in that way! all other BGC must be connected to RC Rx directly. 

      • Developer

        BTW, we also support the AlexMos gimbal using serial but we've never documented how to do it.  On the Pixhawk side it's very similar to the set-up for the SToRM32 but I'm personally unsure where to connect the serial lines on the gimbal controller which is why I haven't documented it.

        • Hi Randy, is there any progress on the Z1 Tiny2 gimbal to connect to AC?

      • Hi OG, that's not correct, pixhawk supports almost all gimbals:

        • Hay Fnoop! well that why I mentioned Yes and No !

          One channel that's can be used for tilt only ! not support at all ! Alexmos, Mrtenez and Tarot also have other channels ?  there are 3 channels 3 axis on a gimbal? 

          Storm32 is supported fully! all other brush less gimbals are not supported as pas thru!

          • Hi OG

            I just checked to be sure.  3 channels are supported, there are even pretty pictures to setup in the GCS :)

            I've used AC-Copter 3.3 with Storm32, Alexmos and three gimbals with pwm support only (Tarot 2d, Feiyu mini-3d, Zhiyun Z1-Tiny2).

            Z1-Tiny2 is the most super awesome gimbal btw :)

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