ArduCopter 3.2 Released

ArduCopter 3.2 (aka APM:Copter) has been released as the default version replacing AC3.1.5. This is the exact same version that we invited all users to test two weeks ago.  Users who wish continue using AC3.1.5 can find it under the "Pick previous firmware" version on the MP's Install Firmware screen.

The full list of changes can be found in the ReleaseNotes but here are the highlights:
Flight Mode Enhancements:

  • PosHold flight mode: similar to Loiter but with direct response to pilot input during repositioning
  • ACRO mode handling improvement EXPO (for faster rotations)
  • Drift mode uses "throttle assist" (similar to AltHold)
  • Smoother transitions between flight modes (i..e when entering Loiter or RTL from high speeds)

Mission Enhancements/Fixes:

New Sensors/Devices:

Safety Features:

  • EKF/DCM check will switch to LAND mode if heading error > 60deg for 1 second
  • Baro glitch detection
  • Pre-arm check for Gyro calibration success
  • Pre-arm check that internal & external sensors (gyros, accels and compass) are consistent (Pixhawk only)
  • Parachute support (Pixhawk only)
  • Feedback to Pilot when taking off in AltHold, Loiter, PosHold (i.e. motors spin up a little as throttle is raised)
  • EKF (new attitude and position estimate system only used for reference in this release)

Bug Fixes:

  • Pixhawk GPS driver buffer overflow that could lead to missed GPS messages
  • Pixhawk I2C bug that could lead freeze up if I2C bus is noisy

Known issues/Warnings:

  • Pixhawk users will need to recalibrate their compasses
  • PosHold won't show up as option on FlightMode screen if you have an old version of mission planner. Please select Help > Check for Updates.
  • Landing detector is more strict meaning it may take longer to disarm after RTL, AUTO.
  • Set THR_MID parameter especially if you have a very powerful copter because "Feedback to Pilot" raises throttle to 1/2 of THR_MID
  • Spline twitches slightly as it passes a waypoint especially if WPNAV_SPEED is set > 500.
  • Dropped support for NMEA and SIRF GPS on APM boards (ran out of Flash space)
  • Dropped support for sonar for MultiCopters on APM1 and TradHeli on APM1 & APM2 (ran out of Flash space)

If you hit issues, please post them in the APM Forum and include a dataflash log file if possible.

Special thanks to Marco and the Beta Testing team from the AC3.2 beta testing thread who put their copters at risk in the pursuit of a smooth, safe release. Here are links to some of their videos: Marco's DJIs900, Holger's Water Tower, Josh's Acro, Ray's TradHeli2&FPV, Raph's Hawaii, PhillS's CommandYaw, Thor's Zombie Run&FollowMe, Phanivyas's Test, Rob's TradHeli, Christian's Test1&Test2, Balloon's Spline, JimJ's FPV, Ultrojo's ROI & Spline&FollowMe1&FollowMe2, Troy's Mission

Thanks also to the code contributors to this release including Tridge, Jonathan, Leonard, RobL, Paul Riseborough, MichaelO, Julien Dubois, David Dewey, Andrew Chapman, Emile, Allyson and many more. If you want to get involved check-out our dev wiki.

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  • I believe that there was a problem with Mission Planner in that it didn't get listed as a possible download.

    Try downloading the newest beta version of Mission Planner because I believe that Michael Osborne mentioned that he had rectified this.


  • After running Autotune with 3.2 my quad was extremely wobbly. I was going to re-install 3.1.5, but the previous version is listed as 3.1.4.

  • @Randy i figured you were pretty busy i will have to look at the power module set up again. thanks so much for taking time out of your day!!

  • Developer


    Yes, I've been buried under an impossible number of pings.  It looks like the battery voltage is dropping a lot when the throttle is raised.  Perhaps the battery has been damaged?  The other possibility is that the battery monitor is not reporting the correct voltage.  There's a video on the power module wiki page that goes through how to confirm the power module is reporting correctly although in short, it involves using a stand-alone voltage meter and compare vs what the power module is reporting to the mission planner.


  • @Randy

    did you get my pings ok? i am sure you are buried with a ton of pingls, i just wanted to make sure i was still in the line? please let me know

  • I really appreciate the spline feature. I can't wait to try the laser!

  • @Randy, sent you the requested logs.  Hope they help!

  • Tnx for all the work Randy. Will try it as soon as the weather gets better :)

  • Many Thanks for Leonard that is the exact answer that I was looking for. Well Done. And yes I did hit it with Autotune and also got a slight improvement after some further tweaking. Now I am ready to attach some different camera systems bearing in mind the effects of low frequency secondary mass interference. Onwards and upwards as they say. Am I correct in thinking that a higher IMAX values would be required as larger gimbal weights are used. 

  • Developer

    Hi Denny,

    IMAX is the maximum value that the integrator term can grow to correct for offset CG. It is also important for fast forward flight where there is a constant torque trying to rotate the copter away from the oncoming airflow. You can control your maximum airspeed by reducing IMAX. So when it is low, say 100 or 200 you should find that you can't get the copter to go very fast but you also need to make sure your cg is in the right spot or the copter will lean one way or the other.

    Richard Kennedy, that reminds me. If you want to limit the maximum velocity in stabilize you can reduce IMAX until your maximum velocity is near what you want.

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