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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  • Thanks Paul, I'll do some reading :)

  • How do we calibrate the channels 9-12?  I already set the parameters for those channels. but in radio calibration tab, only channels 1-8 can be calibrated for end points. 

    • Developer


      There's currently no way to calibrate those channels and from what I know it's not necessary because the RCX_MIN and MAX parameters for those channels aren't used.  For example if using them for auxiliary switches, the pwm ranges are hard-coded so <1200 is low, >1800 is high.  If using them as a passthrough to the servo outputs then there's also no scaling required (what comes in from the receiver is just directly piped out to the corresponding output channel).

  • since RC3.2 release the pixhawk has become more sensitive to vibrations (for better filtering). it is very important to have tuned foam pads which are only available form 3DR. what is important is the damping effective of foam when pressed and released. they may look to be same but 3DR has tested the foam on vibration machine (I think so). I had a problem of vibrations when I upgraded form 3.1.5 to 3.2. by changing to 3DR foam the issue got resolved. also the FC should not be touching any part of the frame. and most simple and important step is to balance the props.

    • Don't this this is a pad-type trouble for my case. This is *constant* spikes, do not depend on throttle, movement speed.

    • Developer


      Thanks for the input.  I also recommend the 3M foam that 3DR sells.  Paul Riseborough thinks the HobbyKing ping foam (sorry I don't have a link) may be even better but it's not sticky on both sides so it's a bit more trouble to use.

      We really don't think that copter should be more sensitive to vibration between AC3.1.5, AC3.2 and AC3.3.  We're attempting to make it less sensitive to vibration by increasing the accelerometer range from 8g to 16g, improving the fitering, increasing the read rate from the accelerometers, etc so I really hope that's it's not getting more sensitive.

      If you really think it's more sensitive we'd like to see a log.  I know it's hard to prove it's more sensitive, it probably requires using a borderline vehicle and running back-to-back tests that show bad behaviour on the new firmware but not on the older.  I know it's a big ask but I've never seen such a test done.

      • Sorry for my ignorance, but I just bought Zeal pads for my Pixhawk, and it seems, reading posts here, that Zeal isn't anymore the recommended solution.

        Why is that?

        I had almost no vibration with them on my other APM2 quad.

        • Developer


          I think Zeal pads are probably ok as well.  I haven't used them personally but I've heard some good things.

          • Can you have over damped solution? I have $_12.JPGand zeal under it and flight controller attach with hobbyking Flight Controller Mounting Pad

  • From logs, I see what only IMU1 has such spikes. IMU2 looks better. Where is IMU1 and 2 placed? One on Pixhawk, and second?
This reply was deleted.


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