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

              The backup is only used pre-arming as a consistency check to ensure the external compass is oriented properly.  Also there's no easy way to physically remove an internal compass so because it's there we might as well take data from it.

              • Thank's Randy to clarify, In other way, is interesting to have the int compass chance, It's help me to fly until I recive the ext one and looks usefull in airplanes too; I have the gps near the motor (skywalker)

                • Developer


                  It's not clear that switching to the internal compass would help and it's likely on some vehicle it would make things worse.  The gyros drift but the drift is quite slow so even without the internal compass, the heading could remain fairly accurate (i.e. within 30 degrees) for a minute or longer.

                  •  thank's for comment, now I know that isn't only my problem, (worse with simple mode) , I'm only flying near me now, to tune, check all things, etc. (...anxious) because I notice that, this week I have to pick up my new gps-ext compass and perhaps it's better to disable the int one.

                    PD: But I notice too, that this issue is much less with the pix and 3.3 than the 3.21 and APM

        • I understand that if you have both compasses with 1, the controller uses the ext one to navigate, if ext stop working or disconnect, the pix switch to the int one automatically but, if you have the two enable, the controller check if both readings are consistent, if not, gives an inconsistent err; perhaps, if you have int compass interferences it's better to disable int one? I'm waiting an ext one to try, if you do it after, please share your results :)

          (please tell me if my understand is incorrect)

          • Yes that makes sense thanks Cala!

      • Oh I got it wrong then. I thought that *_use was for internal and *_use2 to external.

        Thanks Randy for clarifying it

    • That's a common question I wish that was in here

  • If anyone wants to use this lua file for FrSky telemetry from PixHawk to a Taranis radio, please feel free. A very nice person wrote this up for me and it works pretty good. drop this into your [model name] folder under /scripts on the taranis SD card.

    in MP make sure you set telemetry to use FrSky protocol, D or S depending on your RX (I have a D8R-XP). No teensy required, For a D series RX you will need a simple TTL to RS232 converter between the FC and the RX.

    With this script you get:

    • current flight mode
    • current heading (direction arrow plus N/S/E/W)
    • vfas lipo pack voltage
    • rssi
    • gps sat count
    • gps lock status (No fix, 3d fix, 3d dgps, etc)  - (right click link and "save link as" then choose to save as "all files")

    • Thanks!!!! I will give this a try. 

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