ArduCopter 3.2 ready for wider use

After months of testing, ArduCopter 3.2 (aka APM:Copter) is ready for widespread use and we invite all users to give it a try.  In order to manage the support load at first it will be available only through the Mission Planner and APM Planner2's Beta Firmwares link.  This link is visible from the regular "Install Firmware" page if you check the "Advanced View" on the Config/Tuning >> Planner page.  On APM Planner2 the "Advanced View" it is under the File menu.

In about two weeks we plan to replace AC3.1.5 with AC3.2 as the default version dispensed by the ground stations.

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 ssupport 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 the 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 CommandYawThor's Zombie Run&FollowMePhanivyas's Test, Rob's TradHeli, Christian's Test1&Test2Balloon'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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  • Developer

    The PM fail can be ignored (PM = PerforMance).  What's happening there is the PM messages aren't ignoring the delays that occur during the gyro calibration when arming.

    The GPS issue is unlikely to be a firmware issue.  It's more likely that the vehicle really didn't have GPS during the flight.

  • This has me worried:

    Size (kb) 8554.380859375
    No of lines 114684
    Duration 6 days, 22:11:00
    Vehicletype ArduCopter
    Firmware Version V3.2
    Firmware Hash c8e0f3e1
    Hardware Type
    Free Mem 0
    Skipped Lines 1

    Test: Autotune = UNKNOWN - No ATUN log data
    Test: Balance/Twist = GOOD -
    Test: Brownout = GOOD -
    Test: Compass = GOOD - mag_field interference within limits (8.12%)

    Test: Dupe Log Data = GOOD -
    Test: Empty = GOOD -
    Test: Event/Failsafe = GOOD -
    Test: GPS = FAIL - Min satellites: 0, Max HDop: 99.99
    Test: IMU Mismatch = GOOD - (Mismatch: 0.62, WARN: 0.75, FAIL: 1.50)
    Test: Parameters = GOOD -
    Test: PM = FAIL - 17 slow loop lines found, max 7.20% on line 108374
    Test: Pitch/Roll = GOOD -
    Test: Thrust = GOOD -
    Test: VCC = GOOD -

    In the logs there are no gps issues (NSat and hdop). I don't know what PM is.

    Took off in stab (no simple/ss), switched to poshold to test before flying a mission, then it started twitching and drifting. I was able to land, but will not attempt again until knowing what is going on.


  • The problem of the unleved fly was corrected. I had to calibrate the accelerometers with the APM outside the copter. 

    I did another flight today with APM with arducopter 3.2 and another crash like the one reporter before. The quadcopter was flying in stabilize, I was moving it to the left and then it turned left and fall into the ground.

    I don't have any clue where is the problem. Can someone try to analyse the logs?

    Here they are:


  • MarkM: That makes a lot of sense. It's explained why this happened. Because in the first flight, the COG was a litle out of correct point.

    And regarding to the cause of the crash. I tried to run it securing in a table and it's all working well. But I don't thrust on it to fly again without discovering what is wrong.

  • AHRS_TRIM_X and AHRS_TRIM_Y compensate for the flight controller not being level in the frame but both of these are set automatically when you do the 1st position of the accelerometer calibration. Hence why they won't be 0 to start with and why the quad has to be perfectly level for the very first step.

  • Where I change the trims to zero?

  • If you look at the parameters, there is already trim built in by default. I didn't know that when I first got the 3DR Y6B and it kept pulling to the right and forward. Being a noob on that much copter gave me fits getting it in the air without rolling over. It so happened I also had the copter CG off in the same direction as the default trim, which compounded the problem.

    So my suggestion would be to first make sure the trims are zero in Mission Planner, then balance your copter by whatever method, and it should take off straighter assuming everything else is set up correctly.

    I ended up using scales to balance my Y6's. If the idea is to have equal weight distribution, it works great. .$8 on Ebay.


  • I will try after with that COG.

    For the tests, maybe I will hang the quad to a table and try to increase the throttle.

  • I fly a Discovery myself (I also use the V frame setting) and you have to get the COG right before flying it. The mark on the bottom plate is wrong and so is the one in the picture above, imo, which is 13-15mm forward of the marking. The motor layout forms a parallelogram so I did the maths based on that rather than just using a median.

    In stabilise mode with no wind my quad just sit's there and that's with 0 trim applied just the initial accelerometer calibration's and the gyro calibration on power up. Using the COG from that pic my quad would constantly pitch forward.

    Have you tried flipping the props over and moving them round the quad one motor position and powering up the motors? That way they will be pushing the quad into the ground meaning you can load the motors and esc's to see what they do at higher throttle positions.

  • This guy had the same forward drift issue.

    RC Groups - View Single Post - COG vs COT and Implications
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