APM Copter 2.9.1.b has been released


APM Copter 2.9.1.b has been released to the Mission Planner and is also posted in the downloads area.
2.9.1b is a maintenance release incorporating changes to 4 default parameters that have been optimized since 2.9.1 was released.  There are also 4 minor bug fixes.  There are no code function changes or additional features.
The changes are:
1) reduce default INS_MPU6K_FILTER to 20hz
2) reduce InertialNav Z-axis time constant to 5 (was 7)
3) increased max InertialNav accel correction to 3 m/s (was 1m/s)
4) reduce yaw_rate P default to 0.20 (was 0.25)
5) bug fix for alt_hold being passed as int16_t to get_throttle_althold_with_slew which might have caused problems if you climbed over 320m.
6) bug fix for throttle after acro flip (was being kept at min throttle if pilot switched out of ACRO mode while inverted)
7) bug fix to acro trainer to do with roll correction 
8) prevent cli from being entered more than 20seconds after reboot.
Users are recommended to:
    Update Mission Planner to 1.2.41 and
    Update their flight code to 2.9.1b from the Firmware tab on Mission Planner. There is no need to go through a new configuration process in the Mission Planner.


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  • Developer

    *** For those testing AC3.0-rc5 ***

    We have found an issue with the CIRCLE mode initialisation code in which the copter can twitch violently just as circle mode is initialised.  We know the issue and will create an -rc6 to resolve this issue but this may take a couple of days.  Until then please do not use CIRCLE mode.


    This message is only for AC3.0 testers.

  • Need some help!

    First flight this morning didn't end well!  I have flown my DJI 450 quite a few time testing Stab, Alt Hold, Loiter modes successfully.  This morning my goal was to test RTL.  I set RTL as the third mode switch and went flying.  Once I selected RTL the quad turn toward home and went to 15 meters altitude, then started to head "home".  Once it got close to home it started to pitch or roll back and forth aggressively, I was unable to switch out of RTL to Stab mode in time.  It appears to me that I had lost all GPS sats just as the quad got close to home.  Can someone help me to confirm this?  Also what would cause the GPS Sats to be lost suddenly?

    I have attached the logs.

    Thank, Todd

    2013-06-10 08-36-00.tlog

    2013-06-10 11-23 66.log

    2013-06-10 11-23 66.kmz

  • I'm having a problem with not being able to arm because of mag field error message in HUD. I'm using APM2.5 and my magfield reading in MP is 126. I understand it should be higher than that. I've done the live calibration dance several times. Also did the level in MP that goes through each axis. Not sure if that is necessary if you do the live calibration. I know I can disable the prearm checks but what can I do to fix the magfield error? Is it necessary to do the CompassMot also? My Loiter is very good and heading is accurate.

  • Hi All,

    I have strange problem on my board.
    It keep reset to default parameter/factory every time I disconnect and reconnect the lipo or USB.
    any parameter changes stored while it was on power, but will reset to default parameter everytime it powered on using lipo or usb.

    Any suggestion on how to resolve it?

    Thanks in advance.

  • Guys,

    Im flying 3.0RC5 and till Friday it was very pleasant. But then "something" has happened and Im unable to get back in that "sweet" state. On Friday morning it refused to get armed. I tried everything what I know, but iy refused to cooperate. So I erased EPROM and reinstalled firmware. Went through whole calibration process (RC calib, Compass Live calib, Compassmot, Level, declination fixed 3.14 for our location). Enabled IMU log (see picture attached). It works as expected (just slighly more shaky than before), Althold keeps altitude, but anytime I switch loiter, it started to fly in circles, still bigger and faster (is that what you mean by Toilet Bowling?) and it finalize circles by flyaway like Apollo heading Moon. Im able to manage it and get back by Stabilize, but as it happen anytime I switch loiter ON, it makes Loiter unusable. Strange is, that last week, before that "something", I had not just loiter reliable, but Circle as well. With the same hardware. Any idea, what can be wrong now?


    param list.jpg

    PID 30 default.jpg
  • Looking for the log_bitmask parm in MP.

    I'm setting up another PC and I can't remember how to generate the list of parameter in Mission Planner... I'm missing the log bitmask (log_bitmask) parm in the "Advanced Params" screen...


  • I'm not finding anything in the wiki about pre arming checks, probably because it's a new feature. What's happening with me more than 50% of the time, is it's refusing to arm. One time I saw something about mag check on the HUD so I redid the live calibration 60 second dance and then it armed. Then I fly some, land, change batteries and it doesn't want to arm again. Where can we see in MP the reason it refuses to arm? It doesn't always show up in the HUD. I'm using 1.2.53 of the planner. I know it's not a GPS issue as I have 10 sats. Loiter and Alt Hold are perfect. v3rc5.

  • Just flew the newly rebuilt quad that abruptly visited the roof the other day. Tweaked the parameters some and tried it out. Alt Hold is virtually still in the air and loiter is very good. Only the wind is moving it around and the altitude variations I think are due to pressure changes in the enclosure that I need to work on. Video shows a brief bit of it in a stiff breeze (watch the trees in the background in the latter part of the video). Excellent work guys.

    Oh yea - and it no longer tries to land 12 miles away :)

  • Hi Randy and Dev Team,

    Rock solid loiter and alt hold on RC5 are finally achieved.. Thanks for your hard work.

    Below is my vibration values, is it on normal range?



  • Discovered the problem. I'm using this dome.

    It has the 4 ovaltangle cutouts at the bottom and it has some thin slots near the top. Maybe 10 of those. Maybe the baro has more authority v3 than in 2.9.1.b? Without this top and with the tuning I had, which I hadn't spent much time tuning, was very solid. I had some TBE but I know that can be tuned out with declination tuning. I just wanted to get these wild ups and downs figured out and it looks like it was creating some strange pressure changes in the dome.

    I thought before I cut some more holes in it, I would tape up all the holes. After doing that, it definitely got better but I still had some ups and downs but very tame compared to before.

    I think what could be happening is either a gust of wind comes in from below or it starts to descend into it's own air and that is causing a rise in pressure inside the dome so it quickly tries to compensate in a more violent way.

    By closing all the holes on the top. I still have the problem of pressure differential but because the outflow of pressure was being contained, making the changes calmer. Like when you live in a windy location like a beach. If you open all of  your windows then it gets very violent inside but close all and leave one or two open on the side of the wind and it's much calmer.

    So is the solution only cutting up the top to help it breath better? It's easy to do but not sure how far I will have to go. I don't it should need much to release the pressure.

    Also my APM2.5.4 is not in it's case. It has a nice isolation screw system and the baro is NOT covered. Even with it not being covered and the clear dome off, the alt hold and loiter was great!

This reply was deleted.


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Aug 25