ArduCopter-3.0.1 released!

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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  • Been out flying today with my octo, luckily I had my laptop with me as the APM 2.5 lost its accel calibration again and rolled its self into the ground on take off. Plugging in the laptop revealed the HUD leading over to one side on a flat surface.

    Last time it happened I just recalibrated and everything was ok for the last 4 or 5 flights.

    Did a rough calibration in the field and it flew ok, drifting one way but will recalibrate at home later.

    Is any one else loosing their calibration?
    It's costing me props each time it's lost :(

    Just seen a reply from Randy further back on this forum when I had the same problem.
    It sounds very much like you accidentally triggered the auto trim. It's somewhat easy to do because it's activated if you hold the throttle down and rudder right for an additional 10 ~ 15 seconds after the copter arms. I.e. if you're trying to arm the copter and hold the throttle down and rudder right far too long you'll activate autotrim. Then as you fly around for the first 25 seconds the trim will be adjusted by your roll and pitch stick inputs.
    You'd see -9 on roll and pitch because the autotrim has a max of 10 degrees that it will adjust level by.

    Don't think I would of done this as I count to 5 by which time it's armed and I let go the sticks. Would connecting the APM to laptop via USB with no tx on cause something similar? I did this around the time but can't remember if it was before or after.
  • Hi Guys I have noticed in MP when setting up Modes ... when i switch from Stab To AltHold and Loiter it MP does not report the switch position above the settings .. i.e ..the green bar moves to the correct spot , but the writing above does not report correctly ?  Any one else seen this issue ?

  • Optical flow is one I really need. Do you know when 3.0.2 or 3.1.0 will be ready?


  • I wish to change the maximum yaw slew rate when I am in Loiter for smoother AP work. I have tried to just use a little yaw stick and dual rates but it’s hard to get a nice smooth yaw rate.

    I changed the AUTO_YAW_SLEW_RATE and now it’s perfect for missions. What parameter do I need to change to do the same thing for manual stick inputs when in the Loiter mode? I looked at the code and it’s not obvious?

    Other than that V3.0.1 is working well.




  • One question about HDOP and PDOP:

    I can see in AP_GPS_UBLOX.cpp that hdop = position DOP  (PDOP)


    linie 264         hdop = _buffer.solution.position_DOP;


    HDOP and PDOP is not the same, right ?

    why i ask , is because the PDOP value i read in U-Blox Ucenter software is same as HDOP in mission planner 1.2.62,

    HDOP is 40-50% lower in ublox Ucenter.

    Don't known if is bug or not, it looks a little strange to me.

  • I just want to chime in that I have really grown to like 3.0.1 now that I have the tuning down, know how to read the logs and have gotten comfortable with the flight handling. I am by far no RC expert but I have now had 5 successful missions building up from stabilize to just flying loiter for the first time tonight.  

    Having read the recurring theme of stability issues with loiter and copters flipping I was really nervous to jump into this release.  At first I had my fair share of issues as well, including a few flips and some broken propellers.  I also lost a motor but I suspect that was something that was coming and had nothing to do with the flips I had.  

    I found that making sure the calibration of the compass and acceleromter, along with a good compassmot test were the biggest key. I have my quad flying as stable as ever now, exponentially more than at any other time since I started this hobby.  Additionally, finding a really good throttle_mid was also key because I was chasing the sweet spot pretty bad early on.

    I attribute the majority of this to Randy's updated documentation on the logs. That opened up so much more info that I am not guessing anymore. Thank you so much for that.   

    I haven't let the quad go to far away from me as of yet. On my last flight tonight I started pushing it out further.  I hit my battery limit and had to pull it back.  But I did several iterations of stabilize to loiter tests, I had flown successfully switching to Alt_hold last night that I felt comfortable going to loiter.  Every time it switched It dead stuck to its position.  One thing I did notice is that when I tested roll and pitch while in loiter it seemed very sluggish and not nearly as responsive.  I had seen others mention this feeling, but on some cases that was while it was in auto mode and switched to loiter. 

    I was surprised looking at my logs how well the quad performed, as I still need to improve my vibrations. They aren't crazy but it can be improved.  All in all I am very pleased with how this version has performed now that I am getting comfortable with the calibration.   

  • Hi,

    I have been having a small issue with all of my copters. what happens is when I release YAW stick the copter kind of  hop's up about 1/2 a foot, at worse, usually less then drops back down to the alt it was at. I am pretty sure it is a param but I am not sure which one. can anyone help me with this? 

      It seems like the faster I am yawing and how fast I bring the yaw stick back to neutral effects this jump. for example, if I bring the yaw back to neutral very slowly I get just a very small jump, hardly noticeable. if I go from full fast yaw spinning and just let go of the stick I usually get a pretty good jump.

    thanks for any help on this.

    BTW, I just did a maiden fight with my first Octa-quad, I have to say I was leery of trying this copter, turns out to be the most stable copter I have. I love it, you guys did a great job on this FW. I cannot get over how well it flys. also I was surprised to find it draws close to the same current as a quad I have with the same motors/esc's while hovering around anyway


  • Hi guys! I have an issue with this final 3.0.1 release! When it was in beta stage it was all ok, but when it came off from beta my ESCs wont arm, they do the lipo cell count and then they constant beep... Any idea what this might be? I have calibrated them individualy and the issue remains! Maybe hardware problem with the ESCs?

    By the way nice work guys! ;)
  • Hi,
    I saw somewhere instructions to update the ATMEGA32U2 (PPM encoder), really need to do this update?


  • possible logging bug or have my board already gone bad  :| ...  I can't graph my AccY


    2013-07-25 15-59 3.log
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