• I also have this problem. What works is logging in via NSH and rebooting the px4flow driver:

      -Use mission planner

      -Enable advanced mode, then click the Terminal tab

      -Select NSH


      -Type "px4flow start"

      -px4flow status (or was it info) should tell you the driver is running

    • Horsj--

      I've had the exact same bad altitude problem on my quad (w/PX4Flow and Lidar Lite).  Same as you, I've had the altitude value slowly/steadily climb while the quad is sitting on the bench and while hovering as well (at a height 1-3 meters).  On the GCS HUD, the quad reports a slow and steady climb in altitude and ultimately stops at 40,000 meters, even though the rangefinder is reading accurately at <1 meter on the bench.  The issue only occurs sporadically and, on 2 occasions, I didn't notice it happening on the HUD while hovering the quad. I put the quad in Land mode and the quad literally fell out of the sky (seemed like full motor stop).  Perhaps because the quad thought it was at 40,000 meters?  In any case, I've destroyed 2 optical flow sensors from the impact :)

      What flight controller are you using?  I was using a PixMini and had assumed it just had a bad barometer.  If I see it happen again, I'll try and post the logs.   

      • Mine fails consistently, if it is not powered with the USB first, so I guess it is easier to reproduce the problem and debug. I have calibrated it as far as I can, but don't really feel like flying it knowing there is some strange, potentially unpredictable stuff going on.

        My setup is Lidar-Lite V1, HKpilot32, both of which work really well, and the PX4Flow is from HK too.

  • To Summarize,

    PX4 Flow on ArduCopter does not work with GPS due to the required Parameter Setting

    EKF_GPS_Type = 3

    in Mission Planner. 

    The PX4Flow ordinary firmware has received a major update I understand, one or two months ago,

    containing an LPE software filter:

    but of course we need to use a different Firmware for the PX4FLOW on Arducopter,

    which as been developed in December 2014:

    I hope these improvements will find their way on the Arducopter platform.

    What does EKF setting mean by the way? Is it also some sort of Filter?

    How will Flight Modes that ordinarily require GPS behave 

    and how will it be possible to do Waypoint navigation (Auto Mission) when the Px4Flow is connect / turned on,

    as both are not supported together yet?

    Thank you

    PS I have also updated this comment:

  • Hi Paul,

    I'm not clear with wiki on how to calibrate OF. It just says "calibrate" but not more explanation. Could you help me to get further information on calibration?

  • Hello Paul,

    It would be very nice to have the redundancy of both the Optical Flow and the GPS.

    Do you know when this will happen?

    So If I am not mistaken, GPS  *WITH*  Optical Flow does not work together yet?

    So when doing an Automission using waypoints, it will soley rely on GPS but not on Optical Flow?

    Also the Custom Firmware was built in December 2014

    but the "common" firmware for the PX4Flow for the pixhawk has received

    a major update recently

    Do you this willwill be incorporated soon?

    Thank you

  • Thank you Paul, as usual, for useful information!

  • Sorry if this was already addressed, but what is best suited for use over water or even snow/ice, which is where I like to fly for video/photos? I recall asking this in another thread but not the answer.


    • Developer
      Optical flow is no good over water... Sorry... :(

      As its tracking what it sees, it may either track wave motion, or the clouds above... But either way, not what you want.
  • Gotcha. Thanks again. 

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