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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  • Hi,

    I am wanting to monitor voltage and current on a PX4, I also have the PX4IO and want to use the virtual pins 100 and 101.

    I found the pin 101 for current but I am not sure where the pin 100 for voltage is? It doesnt say where the virtual pin 100 is in the wiki like it does for the pin 101?

    the wiki says


    • PIN = 100 A virtual analog input pin for voltage of a battery connected to the 6V to 18V input of the PX4IO voltage regulator.
      • This is the normal pin to use for LiPo monitoring on the PX4IO.
      • If using this pin then set VOLT_DIVIDER to 1 for correct battery voltage reading.
    • PIN = 101 A virtual analog input pin for a battery current sensor connected to the “current” pin next to the power connector on the PX4IO.
      • This pin can accept up to 3.3 volts.
      • WARNING: If voltages higher than 3.3 are used there is a risk of causing the PX4IO to malfunction, forcing the PX4FMU to reboot.
      • For use with a current sensor, a 0.1uF capacitor between this pin and ground will help reduce “noise”.


    also, is it ok to use the current monitor output from the 3dr power brick on pin 101 for current? (with the .1uf cap?

    thanks for any help,


  • Can I upgrade the PPM encoder on my apm 1.4 or is it only for apm 2.5?

  • Hi, has anyone idea how to fully remap channels without changing mode in radio ?

    I have JR radio and FRsky. I'm using PPM.

  • Hello All. First off, thank you to all who have worked so hard for this community!!

    I just had an event happen with a new quad I assembled.

    I know the setup was incomplete on this quad. I had intended to fly only in stabilize to test my camera gimble.

    I had an RTL trigger with a resulting significant crash and would like to know why.

    If someone could please help analyze my Flash log(no telemetry during this flight) for clues, I would greatly appreciate it.

    My setup is as follows:

    APM 2.5 with ublox and seperate external compass.

    Dji 450 motors and arms and 10x4.5 props with a custom spider style frame.

    30amp simon K flashed f30 speed controls from RCmanchild

    Tarot Gopro gimbal with separate 1000mah 3s pack

    Single 2800mah 3s main pack(incorrectly setup as a 5600mah dual pack in apm)

    FRsky tfr4-b receiver with ppm single input to apm

    Futaba T8FG transmitter

    900mhz 3dr telemetry( Not connected during this flight)

    The flight went like this. powered up quad, turned on Gopro(in wifi mode) and took off to get an aerial shot of a bus leaving an event. It was windy, but quad was quite stable. I got up to about 100 feet alt and about 100 feet away and quad did a piroette(spelling?) then stabilized momentarily, then pitch hard forward and away it went from 100' to the ground at about a 25degree angle. I know the logs show RTL triggered. Can someone tell me specifically why?

    What I assume was a Radio failsafe. But it appears to me the roll in and pitch in are still registering my stick inputs.

    Thank you for any help on this,




    2013-09-07 20-41 6.log.gpx

  • Could I have a few thoughts on ‘flashed’ ESCs.

    On my first quadcopter build I used some pre-flashed simonK 30A escs. They were ‘fit & forget’ as all has been OK with them and the copter can be tuned very well.


    Now I am on an octa build using the same motors MT4008-12. I have bought the t-motor 30A opto pro ESC, which although advertised as ‘fast’ and optimised for Multirotor but still have ‘jack of all’ firmware. The octa will be big and heavy so Im guessing a super fast response is less important than with a 450 size. My new ESC use the silabs chips, which I don’t think can be flashed with simonk but can take the BLheli. Its not easy to do so is it worth it?

    Basically I wanting to hear that many people are getting on fine with standard ESCs, especially on larger machines.


    By the way, what are others doing as far as power distribution is concerned on big machines? If the autopilot demands full power that will be 240A. I suspect the APM power module will not be happy with that.


  • Hope that this is the correct forum for 3.0.1 questions on traditional heli. I'm flying a Trex-450 and have the APM at 3.0.1. I've tried to set the cyclic servo minimum and maximum values from 1000-2000 to 1100 and 1900. However every time I save / write the parameters and power cycle or reconnect via mavlink they revert to 1000-2000. Is this a know bug or might I be doing something wrong? 

  • OK, my quad is just a little piece of trash I bought just to see if I liked this sorta stuff. I've been flying RC planes and Helis for just over 40 years and decided to give quads a try. Darn, I was hooked. I already had an APM 2.5 in one of my planes so I ordered one for my little junk 100 dollar eBay special. After loading 2.9.1b and flying for a month or so I decided to load up the new 3.0.1 firmware on it. Big improvement. Same day, the little quad was attacked mid air by a large bird. Result, no damage to the bird but the quad was found three feet under in clear water. After drying everything out and checking for what was usable and what was not, I order 4 new SimonK ESC's and a new "Combo" uBlox GPS/Magnetometer.

    Man what a difference the off-board Compass makes. We have some guys at our flying club running the Naza stuff and I was always very impressed with the "GPS Hold" and how rock solid it was. They were equally impressed with my way-point navigation ability but not enough to give up their Naza.

    Well, that is, until they saw it with the new GPS/Compass. Their Naza hasn't got anything on my little junkyard dog. That thing is unbelievable. I mean it when I say rock solid in loiter. Even in a fairly strong wind you would almost need some type of mark on the ground to see if it moves. Just WOW, and also excellent work on the new 3.0.1 firmware to compliment the new GPS module. Thanks to all who put in their hard work to make this possible.


  • First time in a while that I post something in this thread again. I'd need some advice.

    I changed the drive train on my copter. Before I had 2830-800kV motors with 10x4.5 props. Now I have 4822-390kV motors with 15x5.5 props. I didn't change anything else - also didn't retune yet. At first glance, the copter seems a bit overtuned, showing some wobble in ground effect and some bouncing when letting the stick loose from extreme left or right. Otherwise, it seems ok. Loiter without wind is fine, wind in loiter causes slight wobbling and wandering around, although the latter might have been caused by bad HDOP. Forward flight shows partially ugly wobbling.

    I do see a massive increase of vibration in the log but it's generally still well within the limits.

    Now, my questions:

    • What kind of PID change would I have to expect from this kind of change in the drive train? Rather higher PIDs or rather lower PIDs? When retuning, in which direction shall I rather go?
    • My guess is that much of the new vibration comes from the overtuning, because the wobbling comes mainly with wind in loiter or appears in forward flight. Is this a reasonable assumption?

    Logfile is attached.

    2013-09-08 16-53 2.log

  • Hi Randy, ok did alot of testing on the bench

    Test 1


    Laptop running MP 1.2.75  RFD 900 on ground station using a 2cell lipo through a 5v reg.  

    current quad octo config, 

    5v reg supply for apm and reciever

    another 5v reg for RFD900 (grounds are tied, 5v seperate)


    RFD settings are 57600, air rate 64 (back to default config)

    Connects fine through modem. (no usb cable in sight...)

    I can wiggle the vehicle around and see Artifical Horizon (AH) responding pretty quick.

    Ok so now I arm the vehicle, and raise the throttle to hover point ~50% and wiggle at similar rate as before..... AH getting limited data though, I am lucky if it moves every 5 seconds.

    NEXT test...

    Install current firmware (3.0.1) from MP for quad

    Std Quad-X config on apm (2.5,) 

    (this is a same setup but secondary unit to the one above.)

    APM on the bench, connected with RX (ppm sum rx, frsky), RFD 900 NOT Connected at this stage.... 

    Connect via USB, ARMED,..... throttle up, no problem (as expected)

    DISCONNECT USB, Connect rfd900, Connect, arm throttle up no problem.

    Next test Hexi config. ran through same procedure as last one, same results

    Now the interesing one. 

    Std OCTO config.

    Connected via USB,.... wiggle and AH ok..... ARM raise throttle and HELLO we have a slowed AH again. much quicker than through RFD but none the less slowed.  Same test through RFD and very unresponsive.

    I use these for photogrametry work with many waypoints on missions, It would be nice to find a solution.

    Can the dev team do the similar testing for themselves and tell me if they see the same thing... Don't think the type or frequency of modem is an issue, just the fact that it is there...

    BTW I am a avionics tech who has been operating UAV's professionally for many years (over10....)

    I am pretty sure this is in the code somewhere....

    Any help would be much appreciated!\



  • Randy,

    Quick question: my Quad descends almost exactly at the set speeds. However, my Octo simply does not want to go down. It will go down, but as a snail on a threadmill going backwards. I've tried a variety of settings: Throttle Accel, Throttle Rate P & D. Do not know what it is. Alt-hold is just fine. 

    I admit that I did not do the compass mot on this, nor did I look at vibrations. That is also the reason that I did not include a log file as I don't want to waste your time looking at it, however, a brief reply with some ideas would be appreciated.

    Alex P.

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