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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    • All good with rc2 for me, have tested multiple times on three aircraft with no concerns. In fact I am totally impressed with the accuracy and stability. I was able to control and safely land my 1 meter hex with a motor arm twisted 45 degrees. I have seen nothing on the forum that looks like firmware stability issues.

      Thanks for the product. RB
    • No problems here.   Stabilize, alt hold, pos hold, auto mission, land all worked fine no issues. 

      • +1, No more change mode issue

    • Hi! I have two problems since rc2, i think :-(
      1) when i raise the trottle stick, nothing happen till 90%. In the logs there is 90% thrIn and about 45% thrOut. Same with pitch and roll for example, the copter starts to do the action when the stick is shortly before its limits.

      2) since rc2, mission planner / tower says "check throttle threshold" and it is not possible to arm until i uncheck the receiver failsafe. It worked till rc1/rc2 I think

      Nothing changed in config, did the normal wizard to configure all.

      Would be very nice if you can help, randy! ;-)
      • Re-calibrate your ESCS and make sure your throttle hover is set back to 50% until you get it worked out.

    • +1 from me - I have done many flights on my QAV250 with rc2 good success. My only snafu was my serial settings getting borked, but I suspect that's a MP issue.

      BTW did you see my question about "Accelerometers not healthy"? I was flying one day with rc2 when it was much colder (0C rather than 15C) and I was getting these all the time. Does switching off IMU2 disable it for pre-arm checks also?

      • Hi
        Plugged mine in in the house about 20 deg went outside armed and flew then after a few mins would not hold position as it was 0degs
        started to slop off so I think gyros or accelerometers didn't like temp change
        Reconnected power outside and flew fine once it calibrated it's self at colder temp
        • you should ALWAYS ALWAYS ALWAYS let it acclimate before taking off. You are begging for disaster otherwise. The sensors NEED to acclimate. If it is warm inside and cold outside I always let it sit unplugged for a good 20 minutes before even thinking about plugging in the battery. These MEMS units are super sensitive and heat/cold can affect them in all kinds of scary ways.  

          • Is it possible to incorporate temperature calibration similar to the one that implemented in OpenPilot Revo? It seems that OpenPilot is essentially dead now, but they had lots of good ideas, which may improve APM, thermal calibration is one of them.

            • If using a hmc5883L it would [and most things are still using this] but if you are using a hmc5983 then I don't think it needed as it already incorporates temp compensation.

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