Pixhawk Mini No Yaw Control


Recently, I decided to get two PixHawk Minis and integrated one for my 250 quad. Everything is built, software loaded and able to get the vehicle armed and hovering however, the quad is not responsive to any yaw input while in hover. Oddly enough pitch, roll and throttle work just fine. Something seems off since I able to arm and disarm using the yaw/rudder input. This feature is consistent even for the second PixHawk Mini that I purchased. Also, I observed the same effect for two different receivers. I also tried reloading the firmware for both the Pixhawk Mini and the ground planner.

So my setup is as follows:

  • Pixhawk Mini with 1.6.5d firmware
  • Quadcopter “X” configuration
  • QgroundControl version v3.2.4
  • QAV 250 frame selected in QgroundControl
  • Spektrum w/Dragon Link transmitter and receiver with V3 software loaded - and - tried Spektrum DX8 with Orange Rx R820X V2 8Ch DSM2/DSMX receiver

Current Key Parameters:

MC_RollRate_P 0.114
MC_RollRate_I 0.045
MC_RollRate_D 0.004
MC_Roll_P 6.00 1/s

MC_PitchRate_P 0.114
MC_PicthRate_I 0.045
MC_PitchRate_D 0.004
MC_Pitch_P 7.00 1/s

MC_YawRate_P 0.200
MC_YawRate_I 0.020
MC_YawRate_D 0.000
MC_Yaw_P 4.00 1/s

Any thoughts for a remedy…probably something simply I overlooked. Thanks all.

Can you share the log?

@dagar here is a link https://www.dropbox.com/s/1bljpp4khtcq6mc/Log%20Files.zip?dl=0 I am using a Windows machine, APM Planner 2.0 is somewhat buggy so I pulled then from QGroundControl. Log File log_3_2017-10-15-16-16-52 should have good data. Thanks for the cross check.

I posted the largest log here. https://logs.px4.io/plot_app?log=91ec9d22-bfe8-487c-8b05-92c354ce623e

I believe it’s an estimator issue. Without a valid yaw estimate you can’t control yaw.

Why is the GPS so bad? Was this inside?


Thanks for the log plots, I really appreciate the in-depth data, a couple of questions and comments:

(a) how would one go about fixing an estimator issue, sounds like a bad sensor – my Pixhawk Mini is mint new fresh out the box? Any way to change parameters for how the yaw estimator is functioning?
(b) what tool did you use to convert the QGroundControl logs into those awesome plots?
© GPS was bad most likely because I did the hover check in the basement. The 3DR GPS/Compass usually works really well when I bring the system upstairs or outside. In the basement I can occasionally get a few good satellites.


I don’t think it’s a bad sensor. Give it another try outdoors with good GPS.

For the nice plots grab the logs from the sdcard and upload them here. https://logs.px4.io/