Remote arming and mode override

Hi all,

I'm involved with an amazing ardurover/boat project that is kicking some major goals.  However, there are a couple of things that I would like to chat about.

1. Remote arming.  I know this is possible via MP, however, the times we have tried it, it's failed.  The message is "Error: Arm message rejected by MAV".  There was a time on the weekend where the boat was stuck on a sandbar and power safety switches has tripped.  Pixhawk rebooted, telemetry established and was going to put it into manual as we needed to reverse the boat off the sandbar (about 700m away) but wasn't possible.

2. Is it possible that when the Pixhawk is rebooted, that whatever mode it is in (say auto), we can get it to override the radio transmitter and default to manual mode?



You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • Developer

    Hi David.  Not quite sure what your after - but this might help.

    On my radio transmitter I have a 3 way switch and a 2 way switch bound to different modes.  It looks like this

    SW1      SW2       MODE

    UP        UP          Manual

    MID       UP          Training

    DOWN   UP          FBWA

    UP         DOWN    RTL

    MID       DOWN     Loiter

    DOWN   DOWN     AUTO

    Even if the Pixhawk rebooted I would be able to use these switches to put the vehicle into any mode I needed - well any of the 6 modes above.  Is this what you are looking for?  This page describes how to set it up.  Its for copter but its the same process.

    Would this help in your scenario?  You could flick the boat APM into manual mode, reverse if off the sandbar and then flick the switches back into auto mode.

    If I've mis-understood what your looking for please clarify and I'll do my best to help you out.



    • Moderator

      Thanks for the response Grant.

      Re the failure to arm point, i'm not sure that would fix it.  We can see the Pixhawk reboot and connect to it with telemetry, but when doing remote arm through MP, it comes up with that error.  We have reverse on RC pass through so once it's armed it shouldn't be a problem.

      As for the second point, the boat is in the hands of non-technical people, so it's quite possible that despite being trained, they would leave it in auto mode - hence the override.

      The boat is in caustic water so unfortunately manual recovery isn't possible.

      I'm happy to have a Skype session if that would help.



    • Developer

      Hi David.  Rover at the moment doesn't support remote arming but I am looking at adding it.  However, I think what your referring to is the safety switch that you press when powered on before the output controls work.  There is a parameter you can set to disable the safety switch.  BRD_SAFETY_ENABLE.  Set this to 0 and reboot and it should come up armed immediately.

      With a boat I'd recommend being careful with this.  It will mean the boat's prop is live as soon as it powers on which could be dangerous.  Its probably safer if you create a procedure to disable the safety switch when you have a problem as you have described rather then having it disabled all the time.

      Regarding overriding the radio transmitter I assume you mean the RC Transmitter?  If your transmitter switches are set to auto however in a GCS you set it to manual then it will be in manual until you either change a switch on your RC Transmitter to a different mode or send a different command from the GCS.

      Thanks, Grant.

    • Developer

      Skype sounds like the best option.  I'll PM you to arrange.  Thanks.

  • Admin


    I have alerted Grant Morphett, our Developer/Programmer, to your issue with the remote arming of the Pixhawk.



This reply was deleted.