ArduCopter-3.1 released!

After months of testing AC3.1 is finally available in the Mission Planner and GitHub.

Warning #1: If the vehicle is left landed (but armed) while in AltHold or Loiter mode for more than a few seconds, the vehicle may suddenly jump into the air the moment the pilot raises the throttle above zero.  The reason is the baro altitude may fall while the vehicle is sitting on the ground.  In AC3.2 this bug is fixed because we reset the target before take-off.

Warning #2: Motors will spin (slowly) by default as soon as the copter is armed!  You can switch this feature off by setting the MOT_SPIN_ARMED parameter to zero.

Warning #3: if you see "Bad Gyro" on the HUD then you may have a blown 3.3V regulator.  See this thread for details.

Warning #4: if you use a sonar set the SONAR_GAIN parameter to 0.8 or lower

Warning #5: Trad Heli users should now connect their main rotor ESC to APM's RC8 output

Warning #6: Trad Heli BUG causes loss of collective control in ACRO mode if swash type set to flybarred (i.e. not flybarless).  Will be fixed in AC3.2.


The major improvements over AC3.0.1 are (full list here):

1. Pixhawk support (Tridge & PX4 development team)

2. Autotune of Roll and Pitch gains (Leonard/Randy)

3. Drift mode (Jason)

4. Improved Acro (Rob/Leonard) and new Sport mode (Leonard)

5. Arming, Take-off, Land in Loiter or AltHold

6. TradHeli improvements (Rob) including:

a) support for direct drive tail rotors

b) smoother ramp-up of main rotor

c) reduced collective for better control in stabilize mode (STAB_COL_MIN, STAB_COL_MAX params)

7. Support for SingleCopter (Bill King)

8. Performance improvements resolve AltHold troubles for Hexa & Octacopters

9. Safety Improvements:

a) GPS Glitch detection (Randy)

b) Motors spin when armed (Jonathan Challinger)

c) crash detector shuts off motors if copter flipped for 2secs

d) batt failsafe option to RTL instead of LAND, gps failsafe option to trigger AltHold instead of Land

e) more pre-arm checks of inertial nav speed,

10. Bug fixes:

a) optical flow working again (although performance is still not great because not integrated with inertial navigation)

b) ROI working (use DO_SET_ROI command)


How to upgrade:
Click on the MissionPlanner's Initial Setup >> Install Firmware screen.  The version numbers should appear as "ArduCopter-3.1", then click the appropriate frame icon and it should upgrade as per usual.

Special thanks to Marco and the many beta testers on the AC3.0.1 thread who put their copters at risk during the testing of this new version and uncovered many problems so that you don't have to!  Here are some of their videos: loiter in wind, patio sonar, autotune, autotune2, roi, beach, acro, vrbrain, tricopter, train spotting, radio failsafe, the tree, double loiter


If you haven't seen it recently, please check out the ArduCopter wiki.


Feel free to post comments below and we're going to use the new APM Forum for support issues so please post your support requests there.

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        • ..probably not,there is no other way...but maybe he knows how stable 3.2 already is...

          • I fly 3.2 now and it is pretty nice. Just a couple small things getting buttoned up and I think Randy will drop 3.2-RC1 very soon.

            • According to the release note.

              EKF can be set AHRS_EKF_USE to 1 to enable or use Ch7/8 switch to enable/disable in flight. I want to try the ch7/8 switch to enable/disable ekf. however, it's not appearing in MP.


              • Sorry Jay.. I'm currently traveling, but intend to actually flip EKF_USE to 1 when I get back. I haven't yet tried it as I was working on tuning the platform as best I can first, but I think I'm at a place now where switching it should be fine.

                • Thanks Josh looking forward on EKF test.

            • Hi Josh, How's the EKF works on this release?

      • @Marco  Thanks, much appreciated, i am looking forward to its release and finally being able to take off in ALT HOLD LOITER like i do in STABILZE

  • Just Downloaded 3.1.4  I will erase then align and calibrate fresh. Using the PixHawk I've found that it requires a 400 Hz refresh rate to the ESC's as a mandatory capability to be solid to control the motors with little latency :-) So far the build is doing great.

  • hi. today i just got time to test my quadcopter after change my quadcopter arm. i tried my copter and i got fly away randomly not everytime in rtl and auto mission.. can anybody help me about this case? its really make me stress.. its fly away in full throttle i think.. thx for help..

    here i Attach my log when it flyaway in auto mission

    2014-05-08 13-47-49 FA in auto.log
    • I think I had the same problem today. I was flying an auto mission and lost all GPS signal.

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