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  • Stephen Gloor February 21, 2013 at 11:48pm

    @Christiaan - Wow two autopilots.  I think that you may be over-complicating it a bit.  I fly planes so I do have a manual control option which is why I wanted the MUX so I really have real manual control rather than the psuedo one in APM2.5 after it was taken out.  The problem with two autopilots is that they may not be in sync and/or initialised when you switch over.  Tridge flies with two however he has a watchdog that detects if one dies and then switches to the other I think.

    I just want dual, really clean power to the APM and have real manual control.  Your diagram looks good however as another commentor said you may have over complicated it and made it less reliable, not more.

    @Bill - the only reason I tied the negative is, with just running a signal line from the RX to the MUX I was not sure they would reference the same negative and the signal would distort.  Connecting SIG and NEG from the RX to MUX would introduce a loop and potentially noise.  I think they are tied together in the sharer I bought.

    I totally agree with the hardware manual which is why i want the MUX.  The rationale is that quads do not have a manual control option so taking it out only disadvantaged the arduplane users who could (and do) still use APM 1 however that is becoming harder and harder with the new software.  The MUX is fairly easy to integrate and I am surprised that more arduplane fliers don't use it.

  • Christiaan van Vollenstee February 21, 2013 at 10:19pm

    @Gary no the FPV is not critical, what is critical is the camera taking airial photos of an area. I am not even relying on the FPV to have signal most of the times all I want when something goes wrong is the plane must switch over to the other APM and return to landing and I will see this once MAVlink is broken. I am going into an industry where failure is not an option.

  • Christiaan van Vollenstee February 21, 2013 at 10:14pm

    Can you draw us a diagram of your setup?

  • Gary McCray February 21, 2013 at 10:23am

    Re Peter Meisters response to me:

    Peter, I knew Batshare was not a BEC I was just saying that using one of those was better than paralleling BECs.

    Possibly I switched subjects too quickly to make that clear.

    Also, Christian, that is a truly elegant redundant system manually switched, if you are using it over great distances I presume your FPV is critical you might want to consider switching it's power in parallel too.

  • Christiaan van Vollenstee February 21, 2013 at 9:55am

    It is good you tell me because I just want 5v at 1amp to power the AMP and sensors, it will be much cheaper.

  • Rob_Lefebvre February 21, 2013 at 9:05am

    Great ideas here guys.

    Christiaan, are you planning on using 2 2S2200 Lipos to power just the APM and not the servos?  If so, that it total overkill.  The APM will run for several days like that.  It will run for over an hour on a single 2S 370 mAH.  And several hours on 800mAH.  I'd suggest just using a pair of 800's.  You'll have lots of capacity, but 2200 is getting into silly territory. 

  • Christiaan van Vollenstee February 21, 2013 at 8:42am

    @Bill: The sensors is only going to work on one apm as the other apm only needs to do rtl as I am planning to do great distances with an expensive camera. The body is going to be an x8 and then later on x10 so space is not an issue.

     

    As with the batshare a discussion previously stated that there has been testing with expensive equipment.

     

    What do you mean that in the APM 2.x the feature was dropped?

  • Developer
    Bill Bonney February 21, 2013 at 7:09am
    The problem I see with batt share is that not being open hardware it's really hard to integrate it into a system, as you don't know how it will behave in a real world setup. Electronics can be a strange beast when you wire it up in what theoretically works, as at the end of the day, theory is a set of approximations and assumptions. Real world characteristics can cause problems in edge cases.
  • Developer
    Bill Bonney February 21, 2013 at 7:02am
    @Christian: that's an interesting design. The challenges I see are how you share sensors?

    That design also raises the question about complexity vs cost. With such a system, the cost and complexity are more than just two seperate planes with autopilots. Testing the more complex system to be sure the fail safe work is also quite the task. With the cheapness of these drones, deposibility is not an issue. Light weight foam planes are also not as big a safty concern as well. ( a golf ball is probably more dangerous! ;-) )

    I do think, as per APM1.x, switch to manual control using a MUX is a good feature for planes. Unfortunately that was dropped from APM2.x
  • Developer
    Bill Bonney February 21, 2013 at 6:38am
    @Stephen: what type of servos do you have? From my research servos draw 400-500mA no load. So under load it's a bit more. The APM/RX/3DR telemetry radio takes about 250mA, so if that's on the 1A supply only you should be ok.

    You should test the negative lines, I suspect they are common anyway. You may not need to connect them.
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