ArduCopter-3.0 ready for wider use

ArduCopter 3.0 is ready for widespread use.  To make the transition easier, this time we are asking people to voluntarily upgrade from 2.9.1b for the next month or so before we make 3.0 the default firmware downloaded by the mission planner.  The new version can be found in the Mission Planner's Beta firmware's link,, GitHub and the new Downloads Area.

Warning #1: A bug was found in the FENCE in which if you lost GPS it could lean at extreme angles as it tried to maintain an invalid position.  This is fixed in AC3.0.1-rc1.

Warning #2: This release has not been fully tested on Traditional Helicopters

Warning #3: GPS glitches can cause sudden and aggressive position changes while in loiter mode.  You may wish to reduce the WPNAV_ACCEL to 100 and Loiter PID to 0.2 (from 1.0) to reduce aggressiveness.

Improvements over 2.9.1b include:

  • Inertial Navigation for Loiter and Auto meaning much more accurate control (Randy,Leonard,JonathanC)
  • 3D navigation controller follows straight lines in all dimensions between waypoints (Leonard,Randy)

         WPNAV_SPEED, WPNAV_SPEED_UP, WPNAV_SPEED_DN, WPNAV_ACCEL allows configuring speeds and acceleration during missions

  • "compassmot" to compensate for interference on compass from the pdb, motors, ESCs and battery.  (Randy,JonathanC) (Set-up video here)
  • Safety improvements:
    • simple Tin Can shaped Geo Fence
    • pre-arm checks to ensure all calibration has been performed before arming (can be disabled by setting ARMING_CHECK to zero).  (video description here)
    • GPS failsafe - switches to LAND if GPS is lost for 5 seconds
    • stability patch improvements to stop rapid climbs in very overpowered or overtuned copters
  • Circle mode improvements including "panorama" when CIRCLE_RADIUS set to zero (Randy,Leonard)
  • SONAR_GAIN parameter added to allow better tuning of sonar surface tracking
  • CH8 auxiliary switch (same features as CH7)
  • works on PX4 (some minor features still not available) (Tridge,PatH)

How to upgrade:

1. Make sure you are using Mission Planner 1.2.59 or newer.

2. Click on the MissionPlanner's Firmware screen and click the "Beta Firmwares" link on the bottom right.  The version numbers should update to "ArduCopter-3.0.1rc2", then click the appropriate frame icon and it should upgrade as per usual.

3691031698?profile=original3. Reduce the Loiter and Alt Hold PIDs if you have modified them from the defaults.  The modified PID values for the 3dr frame can be seen in the image below.

Note: Nav parameters have been combined with Loiter so do not be concerned if you can't find them.



4. If you purchased an APM prior to March of 2013, update your PPM encoder to the latest firmware.

5. Try out the new version in stabilize mode first, then alt-hold, then loiter and finally RTL and Auto.

Special Thanks to MarcoDaveC and the rest of the beta testers for putting their copters at risk during the extended testing period.  Some of their videos can be found hereherehereherehere and here.  Thanks also to MichaelO for the MP changes required for this release.

All feedback welcome.  Please put your questions, comments (good and bad!) below.  

Added by Craig:

Please watch Randy's videos on setting up and flying APM-Copter 3.0 before you go flying.  They are excellent!

3DR Quad Set-Up Suggestions
AC 3.0 "Live" Compass Calibration
AC 3.0 CompassMot Setup      
AC 3.0 Pre-Arm Checks            
AC 3.0 Fence                               
AC 3.0 Maiden Flight Checks   

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  • Moderator

    I have now replaced all my ESC's, from Hobbyking Super Simple 25A to Hobbyking 20A UBEC ESC flashed with SimonK firmware.

    My compassmot level then dropped from 173% to 62% and later to 32% with the APM raised 10cm above it's normal position (2cm above the horizontal prop line and 10cm above any current carrying wires). The motors are definitely smoother and noticeably quieter with these ESC's.

    I set declination back to auto and did the compass dance again. The toiletbowling unfortunately is still there so any nav. mode is pretty terrible.

    My positions declination and mag field details:

    3692758140?profile=originalDespondency looms large...

  • Has much testing been done with it on APM1? I think I will load it onto my crash quad and give it a run

  • On the APM 2.5 I have connected two LEDs:
    Engine LED 4 (arm) on pin A7
    Engine LED 3 (GPS) on pin A6

    Does anyone know the corresponding PINs on the PX4?

    regards Peter

  • The compassmot routine went sideways on me.

    I have 11cm of separation between any current carrying wires and the APM2.5.   It had been giving me compensation vectors of about 30-70%, which when looking at the mag logs post flight, were sending them way out of tune.  So after about 10-15 times of running compassmot and doing captive hover tests in different orientations to try to get it tuned right, compassmot suddenly started reporting 700% to 1200% comp vectors. So I gave up on it and manually tuned my compass_mot values until mag vectors in the logs remained consistent when unpowered or powered. (this took several hours..)   My final values are:

    compass_mot_x: 0

    compass_mot_y: -3

    compass_mot_z: 0.  

    The magnitude of the compass compensation vector during flight is about 50, vs the about-306-magnitude vector of the unpowered (or compensated) earth-field.  That's a comp vector of 16%, more what I would expect from my separation and 16 amp hover current. 

    I'm not crying over spilt milk but I wonder why compassmot would be so far off in my platform? I wonder if other people are unwittingly experiencing the same issue, not knowing because they never examined the mag logs in detail? 

  • Developer

    I'm "glad" because some users are experiencing the problems with V3 like in my tests with beta before release, I'm sorry but some problems had already been reported but not fixed before the official V3 release.
    This means that the group of beta testers is working well, and I'm not drunk... :P
    The problem of small wobbling during Loiter is also related to the mass of the drone, in this S800 that uses ESC with SimonK are not tangible, but it is also possible that only with some SimonK ESC's is more obvious.
    Even the problem of "not relaxed accelerometersor excessive drift of the barometer can genereare some small overshot to the motors (a sorta of glitch) when traveling between waypoints or when fly fast in alt-hold, and not disarm off the motors immediately after the automatic landing (see this video and the other one with two drones).
    The hope is that in V3.1 these problems, already documented in my videos, are completely eliminated.

    However i remind all that remove the vibrations to the board and cover the barometer with this release is imperative, not optional.

    Bests, Marco


  • Hello
    Command ROI.
    I would like the copter with a WP-circle always turns to the center point.
    which command in the MP-flight Planner?

    Thank you for reply


  • Just uploaded this new FW...done calibration..hovered inside my house, is fine..will fly tomorrow outside... I have an external LED, the green led light for dis-arm and arming and blue led for GPS ...notice they blink together simultaneously , both goes solid when armed... Blue led goes solid even though there's no GPS lock as shown in MP,..then blinks when this normal...

  • Those of you using the TBS Discovery frame where is your APM located and what interference are you getting? I have mine located right behind where the TBS Core would be located and I got 55% at full throttle.
  • Hi,

    Got a question about PID setup. I see a very stable Stabilize. No oscillations, overshoot and so on. Feels and looks good. Switching to Loiter it holds position and altitude very well but starts wobbling in x and y. Even in very calm conditions. Which is the right PID parameter to start adjusting? From my limited understanding of the control loops I'd say it is the roll/pitch rates. But why is it stable in Stabilize and oscillating in Loiter then?



  • Hi Randy,

    I just ran a CompassMot per your suggestion, and the results were very disappointing.  I ran the test twice (while indoors), and the results were 160% and 168%.  I have nowhere to move the APM (SteadiDrone-QU4D).  Could the results been skewed by the fact I ran the test indoors?   What do you suggest? 

    (remember, my APM board has to use the relaxed Accell Calibration parameters in 3.0.1)

    Is the 2.9.1b firmware as sensitive to this interference?  (Wondering if I should revert back.)

    Thanks in advance for your assistance.


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