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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  • I started a thread about a condition that will cause some motors to start in an octo configuration with gimbal channels set to A7 and A8. Not sure if this is a bug. I'm using 2.9.1b and APM2.5.4

  • Latest from master flies great. Tested v3-rc3 with stock params on 3DR Quad and 880 motors.

    - Stab. flies as usual. Still gaining height when full forward and returning to level. (maybe tuning will help)

    - Alt Hold. Flew several accu's just in Alt-Hold. 1m above ground and 5m above ground. Is holding within 15 cm. When wildly pushing stick left-right-left the Alt Hold mechanism kick in is great to see. Holds great. In Stab, the copter gains height if not compensated with throttle.

    - Loiter, Untuned, best sofar with stock params.

    Will test RTL and maybe mission later.

    Found that still manual calibr. of compass and inputting inclination manually is giving the best stable results.

    Great job!


  • How can we re-map the motors to different channel outputs? I want to run my quad's motors using channels 5-8 rather than 1-4? I could do this in 2.5.5, but can't find the stuff in this version. 

  • T3

    I wanted to let you devs know that this works great!  My 4kg Octo flies like a charm with 2.9.1.b.  Default params worked pretty well for me.  I dialed down the forward tilt compensation so that cruising speed would be more steady between waypoints: flying at 80 meters up with the target speed set to 6.5 m/s and tilt set to 35, I am consistently seeing cruising speed between 7-9 m/s with nice slow changes. I also increased my ascent speed to 2.5 m/s and my descent to 1.85 m/s.  Keep up the good work, this copter is going to Panama in a few weeks to survey rainforest!

  • how far from the final release of the new FW are we looking?

    all the stuff is looking awesom.. whats the current issues that are trying to be overcome?

  • Guys. I need some help. I really dont know what I am doing wrong. I am testing the new beta firmware and I am trying to use the compassmot command. Problem is when I enter in CLI the compassmot command, I receive the regular message about increase trottle and etc... But the problem is my esc just keep beeping and I did not find a way to arm the motors. Throttle up doent work... So my motors doenst spin under compassmot. Any ideas? Thank you.

  • My reply was deleted due to have made contact  with seller.  It was vacation and problems with mail.

    Soon I will have the Quadcopter :-)

  • Admin


    Walter Olafsen, walthero is on the DIY Drones website.



  • Bonjour,

    j'ai testé v3.00rc3 cet après midi

    mode stabilise: exellent juste quelque réglages trims

    mode Alt Hold: exellent

    mode  loiter :exellent aussi bien que NAZA (voir mieux !) (tient dans 50 cm2! avec un vent de+/- 20 km/h

                      Les commandes sont très douces  & rassurantes

    mode RTL: a très bien fonctionné erreur de  1 mètre dûe certainement  à la qualité du gps

    ma config:

    cadre: TBS Discovry

    moteur 850 kv, batterie 2200mA

    GPS: NEO u-blox -6M  

    APM 2.5; paramatres: originaux

    Météo: couvert, vent: + / - 20Km/h3692727644?profile=original

  • Hi!

    Sorry to bother you all here but what's the current state of the sonar implementation? I just ask because i did some (hopefully) nice code to blend sonar (tested on MB1200 and cheapo HC-SR04 both running in pwm) hight data into baro/acc fusion on my other project. It's somehow conservative / soft because due to the baro/acc thing it's not neccessary to have a harsh sonar override anymore. I can leave sonar enabled the whole time without fearing severe jumps or drops when flying over high obstacles (monuments etc). The terrainfollowing is not as sharp and bumpy (smoothed by baro/acc) but works at decent flying speeds. From a brief glance at arducopters github repo concerning sonar the methods seem to be rather different. Perhaps it could be an alternative for the not so - die - hard - terrain followers. I think this function might give a nice boost while inspecting roofs etc .. without the fear of bumping into the object.

    Cheers Kraut Rob

    P.s.: Reworked the reply and added the core code. Implementing/testing with arducopter should be a 5 minutes job for someone who is familiar with the arducopter code.
This reply was deleted.


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