Pixhawk and mavlink problem


 Is there a trick getting the pixhawk to connect over  USB/mavlink.

 I got a new board arduplane firmware is complete but just can't get it to connect at all.


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  • I sitting here with everything hooked up. I have the six wire going to the GPS, so that isn't the problem. If I fire it up without the I2C line plugged in it will boot fine. Soon as the I2C is connected it will fail to boot and give me those two depressing long beeps indicating startup fail right after the startup success sound.

  • Definitely the magnetometer.

    When I boot up the pixhawk with magnetometer, I get no big flashing LED. When I boot up without it, all good.



    • Well,

       I formated the SD card, I deleted the *.log file and I re installed the firmware a couple of times with no success.

       Suprisingly if I upload the PX4 firmware I could connect via mavlink in mission planner but what I need is the arduplane. So this would suggest it being a software rather than firmware problem.

       nevertheless the engineer at 3DR suggested to send the Pixhawk back to them.

      • Ok, says mag is the problem, but try this...   for me it was the plug for the GPS.  I had the five wire plug (same exact size as the 6 wire plug) in instead of the six wire.  Just count your wires going into the gps.  it should be six.  fixing that and now no problems.  why the frick they would put the connector in there and send it with the ublox when someone buys a pixhawk at the same time...   Find the same connector that came with your pixhawk and connect your gps with it and then the compass as normal.  It worked fine here.

        Mark Miner

        do let me know if it works for you too.

        • Moderator
          Hi mark, firstly thanks for the info- you saved me much head scratching!
          Interestingly my initial connection was ok but was having difficulty in calibration. Following that I started losing the link after 20 secs or so, it could only be restored by unplugging/ plugging the USB. I checked the wire after finding your post and it was the five wire;-) changed it for the six and hey presto- all good!
          Owe you one mate,

        • My six wire connector came with the pixhawk.  The five wire one was in the package with the ublox.

          Mark Miner

          It is in there, or at least it was with mine.  remember, use the six wire.

          • Brilliant!


            Used the 6 wire for the GPS and now all good. Thanks.


            I have the SBUS working.


            Now just have to calibrate everything and work out why all 8 DJI escapes just keep beeping at me!



        • You are probably right,

           Is it a failsafe that no heartbeat will be sent unless all vital components are live (ie compass gps etc)

           I hadn't connected the GPS precisely because I didn't have the right cable, (as you mentioned they send the wrong cable with unit).

           Which basically is going to set me back I dunno how many weeks before my PX4 ships to CA and then back to UK , oh dear !

  • Mark,

    Thanks so much for your post. I had the exact problem.

    I struggled to connect with teh supplied USB cable to load the firmware, "unrecognised USB device", then after a couple of hours, tried changing the cable and worked.

    Tried to connect to MP to configure and no connection.

    Unplugged the magnetometer and it worked perfectly.

    Did you find a solution to get it to connect WITH the magnetometer?


  • I just set mine up.  Take the card out and look at the boot log.  My flash went fine then no mavlink hookup.  Mine is because it would not recognize the external magnetometer.  (  U blox failed, just the compass portion.)  If I unplug the mag part it will connect.  Do you have the success sound and then two beeps at the end?  For me it was the ublox magnetometer.  I will ask on the forum here and then maybe I can plug it back in.

    Mark Miner

This reply was deleted.


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