ArduCopter 3.0.1 has been released and is now available in the Mission Planner,, GitHub and the new Downloads Area.

Warning #1: Compass calibration and reducing interference is far more important than with 2.9.1b

Warning #2: GPS glitches can cause sudden and aggressive position changes while in loiter mode.  You may wish to reduce the Loiter PID P to 0.5 (from 1.0) to reduce aggressiveness (see image below of where this gain can be found in mission planner).

Warning #3: optical flow is not supported but will be back in the next release (AC-3.0.2 or AC-3.1.0).

Warning #4: loiter turns does not maintain altitude.  This bug will be fixed in AC-3.0.2.

Warning #5: This release has only been lightly tested on Traditional Helicopters.

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 (get it here)

2. Click on the MissionPlanner's Hardware, Install Firmware screen.  The version numbers should appear as "ArduCopter-3.0.1", then click the appropriate frame icon and it should upgrade as per usual.

3. 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. Although not directly related to this release, if you purchased an APM prior to March of 2013, update your PPM encoder to the latest firmware (instructions here).

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

Numerous How-To videos are available:

Special Thanks to MarcoDaveC and the large number of testers on the pre-release thread who put 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.

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Oliver, i'm not sure the 360° yaw pirouette is a safe thing.

The problem is that during high or gusty wind conditions, if the user has an underpowered copter or badly set PIDs (something we see regularly from user logs) and eventually the batteries are near full discharge, then a pirouette can push the copter to the limits and cause a crash.

If i'm right a fence breach is reported through the telemetry link.

The APM taking full control during RTL or AUTO modes is a safety thing. We don't want the APM to be perturbed by user input during those flight modes.

You can still switch back to stabilize if you want toggling your mode switch.


Hi Randy and others,

Could someone tell me what the SIMPLE and GUIDED modes are please?

I also would like to know if a custom flight mode where it combines STABILIZE and ALT-HOLD could be defined.


Alt-Hold is Stabilise but with altitude maintained automatically. What are you thinking it is?

Simple mode is described here:

Guided mode is like loiter - but the loiter point is set via the telemetry link - so you can use MissionPlanner and send the copter to a particular point. It can be used to do 'follow me' if you update the guided point as you move, for example.

Alex, you will find detailed informations here for Simple / SuperSimple modes :

And here for Guided :

I don't understand your question about a combined Stabilize / Alt-Hold mode. Could you give some details about what you have in mind ?


Thanks for the info Rick,

 I did fly alot in v2.9.1. before switiching to v3.0.0. I always set my primary flight mode switch to ACRO>STABILIZE>LOITER... I tried the ALT_HOLD once or twice and never paid attention that it actually included Stabilize. I didn't use it much because I think you wouldn't be able to ARM the motors in that mode. Pretty weird that I never realize Alt-hold also combined the Stabilize!!!. I want my 3 main flight modes to be ACRO(manual), STABILIZE w/ ALT-HOLD (which means Alt-hold) and LOITER.

But I think in this case, the only flight mode that I can ARM would be the ACRO mode...

I can't use the GUIDED mode at the moment. Don't have telemetry. But I now know what it does.

As for SIMPLE and SUPER-SIMPLE; What happens when you pull the pitch stick all the way back in these two modes and copter reaches the launch point? Would it go behind you, or stop and hover over head?


Thank you Olivier. I already referred to those links.

About the Stabilize combined with alt-hold. There was a misunderstanding on my part as I explained above.

I always use Stabilize mode and stabilize mode does not include Alt-hold. So my purpose was to have a flight mode that has both Stabilize and Alt-hold at the same time.

You guys actually have a flight mode that I want. That is the ALT-HOLD mode. I tried that one as well but I just tried it once or twice to see how that works and then never used it again. Since I used it for such a short time, I didn't realize it actually had the horizontal stabilization combined with Alt-hold feature. Thus my question above came:)))

After reading Rick's reply, I realized that APM has what I want but under the flight mode ALT-HOLD not STABILIZE. So I will replace my STABILIZE flight mode with ALT-HOLD and be done:)))

However, I think I won't be able to ARM if I pick ALT-HOLD flight mode when I am on the ground. Correct?

Alex - you are correct that in 3.0, you need to be in acro or stabilise to arm.

However, in the upcoming 3.1 you will be able to arm in stabilise, acro, alt-hold and loiter as long as you are on the ground. This was done as part of Randy's improvements on taking off and landing in alt-hold and loiter. Really looking forward to testing this, just not had time yet.

Alex, for your Simple / SuperSimple question here is what it will do :

Simple mode : copter will come back to you (if you did not rotate yourself since take off and copter is in front of you). When it will reach the take off point, it will continue its course straight and will fly behind you indefinitely. Simple mode locks control direction according to yaw heading at take off. Location of the copter has no influence about control direction in this mode.

SuperSimple : copter will come back to you and will continue to fly behind you after take off point overshoot. But when it will overshoot the takeoff point plus 10 meters, it will update the control direction to the line between you and the copter, and the copter will come back to you again. If you keep the pitch stick backward indefinitely, it will fly 20 meters lines segments centered around the take off point indefinitely.

SuperSimple is like Simple inside a 10 meters radius. When you are outside the control direction is continuously updated. And when you enter again in the circle, the last updated control direction is kept.

The control direction is the direction the copter will go when you push the pitch stick forward.


Do these modes (Simple/SuperSimple) use ONLY compass or Compass+GPS?

Himm, I asked this question but as I think about it, I think I came up with an answer to my own question.

Simple Mode = Uses only Compass

Super Simple Mode - Uses Compass + GPS.

Am I correct?

As said by RickP you will be able to arm and take-off in Alt-Hold with version 3.1.

But it is mandatory to keep the stabilize mode for safety reasons if the pressure sensor has a problem, or if the weather or local flight conditions become so bad that the pressure sensor becomes fanciful.

Those difficult baro conditions can be sometimes met when flying near the ground or between large walls causing pressure changes.

Do not forget that the altitude baro is basically an atmospheric pressure sensor and because of that can be fooled by fast atmospheric pressure changes. Nevertheless this problem is mitigated by the APM inertial altitude control.


Simple use only Compass. Supersimple use Compass + GPS outside the 10m radius circle centered at takeoff location. It does use only compass inside.

If GPS is lost in SuperSimple, then the circle limit will not work anymore, SuperSimple will switch to Simple, holding the last control direction update. This can cause flyaways for untrained pilots.

There is a CH7 or CH8 function to reset yaw heading to the armed yaw heading that can be useful in this case.


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