RADIAN Tilt Problem

Discussion in 'Radian' started by Andrew-Crinson, Aug 17, 2013.

  1. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I emailed him but he is several timezones away, so give him time to respond. :)
    Andy.
     
  2. John Cunningham

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    Hi Guys,

    Sorry for the delay - I'm busy preparing to go back to the UK later today.

    I think they key point is the yellow LED going out. This means the Radian is not receiving data from the daisychain link for some reason. It could be wiring or an internal radian issue - the trick is to diagnose it by swapping stuff out. Remember it could be the roll radian sending the data, the wiring or the tilt radian.

    The first thing to check is if only the tilt yellow light goes out (pointing to the roll->tilt link) or does it go out on the roll radian as well ? (pointing to the pan->roll link).

    As mentioned, the Spektrum should plug into the Pan radian. As I recall, once the inter-radian daisychain link has started it does not stop if the receiver goes into failsafe so we can rule out the RC radio/receiver side of things (I'll double check that).

    JohnC
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Thanks, John.
    Andy.
     
  4. Andrew-Crinson

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    Hi John.

    We have swapped out all radians (same firmware 1.03 41-99) and even changed from spektrum to Futaba S-BUS, and we still have the same problem. However your right though, when the un commanded movement on the tilt occurs the roll radian yellow light goes out for a moment along with the tilt. This happens with new radians and with the Futaba as well. When the spektrum was in use we did have the satellite receiver plugged into the pan as per normal. I have listed the setup earlier in the thread and we have also changed and relocated the 5v UBEC.

    The wiring is correctly daisy chained from pan to roll and on to tilt, and we are using the leads supplied with the radians. This happens approximately 4 mins on the bench and in the air whilst in slew mode. It also happens with or without an led shutter trigger. We have also tried putting the power into port two on the pan but the problem persists.

    All the best

    Andrew
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Andrew:
    Thanks for the summary. Using Sherlock Holmesian thinking, that raise the question of what you have not changed and pondering whether whatever has not been changed could possibly be the cause of the problem?

    Also, if you were to have ONLY the tilt axis active does the problem still happen? This would mean wiring the Rx and power to the tilt Radian and Servo. If it works, then add the other axes back in one at a time just to see at what point the failure returns (assuming the failure to be deterministic).

    Sorry my ideas are not very specific, but those are the diagnostic strategies I would use.
    Andy.
     
  6. Andrew-Crinson

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    Okay Andy we will work from the tilt backwards. Good thinking. And the only other thing that's not been changed are the radian leads...
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    OK Andrew. Keep us posted. As you say, you start to question whether the wires are acting like wires or whether there's an internal break and dodgy contact somewhere. It's happened to me, so there's a chance....

    The good news is that the fault seems reproducible, so you know that if you can work backwards and take stuff off/out of the situation and it starts to work, then there's a high probability that what you last removed was the cause.

    We'll cross the bridge of "Well it's still happening and I've changed *everything*...." when we come to it! :)

    Andy
     
  8. Chris J Ayres

    Chris J Ayres Member

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    Ok tried some of the testimg suggested. Isolated titl radia and plugged power and receiver in it. Ran a test fro 10 mins and no problems. Then repeated adding in the roll and again after 10 mins no problem. Introduced pan and then the problen happens. So i then changed the cable between pan and roll and the problem still happens. Then i put the spektrum receiver into roll but left power coming from pan and it is working fine. Of course no pan control.

    So what next?
     
  9. Chris J Ayres

    Chris J Ayres Member

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    This must be software?
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Chris:
    So just to confirm, it's something to do with the Pan radian being on-line that's causing the problem.

    This is one of those issues where it would so much easier for us to help if we (and I mean forum members) were standing next to the copter on the bench -- so might it be possible for you to take some images of the installation of the pan Radian, servo, and receiver in the configuration where the problem happens. Also, can you take screen captures of the Radian software for pan, tilt, roll in the configuration where it fails.

    At least we have now got to the point where you can make the problem go away and re-appear -- that's a giant diagnostic leap forward because it's no longer an intermittent problem that you cannot reproduce. That said, now we have to hunker down and figure out what about the pan axis is causing a problem.

    Apologies for asking you something you may have already answered but it's hard to keep all the data in my head -- have you tried swapping the pan and roll Radians (with appropriate re-programming) to see if that makes the problem go away?

    Andy.
     
  11. Chris J Ayres

    Chris J Ayres Member

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    Andy,

    Yes all radians have been replaced. Attached are the config screens for each radian. The failure is momentary and there is nothing evident in the diagnostics screen. The only difference in the diagnostic screen is when the problem occurs and I have the TX stick other than centre. In this case the SLEW % in the diagnostics screen would not show 0.00% as in the example attached but a - or + % depending on which direction and by how much the TX stick was being moved. Also note that the new SLEW % in such a case would be the position that the Radian returns to as what it thinks is its rest position. Hope that is clear.
     

    Attached Files:

  12. Chris J Ayres

    Chris J Ayres Member

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    Andy, Here is another shot of the TILT radian as the problem occurs. Also a youtube video. Notice the slew and mode bars are red not green as when working normally. It is as though the TX has sent a signal to switch to stabilised but not slew mode.

     

    Attached Files:

  13. Gary Haynes

    Gary Haynes Administrator
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    Also it loses SBUS connectivity when the mode changes.
     
  14. Andrew-Crinson

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    Great work Chris. But chaps before we start blaming the spektrum we have already tried Futaba S-BUS and had the same issue. What is interesting is that its only the pan radian that says spektrum valid. Just thought I would make this statement before we get side tracked.
     
  15. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Any reason for not checking the "Off unless using Spektrum" box?

    Andy.
     
  16. Andrew-Crinson

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    Hi Andy can you just explain that check box please?
     
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Sure. If you're using Spektrum, check the box. :)
    Sorry to sound smart-arse, but, but I really don't know any more than that -- I suspect it's to correct something in the firmware. I've seen reference to it earlier on the forum but cannot find the correct thread.

    I'd just check it, write the config back and see if it works.

    Andy.
     
  18. Andrew-Crinson

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    It can't be that simple lol... Okay do we check the box on all Radian? Thanks Andy
     
  19. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Just remembered -- I think it was to reduce some noise issue re: Spektrum or to reduce twitching.
    Andy
     
  20. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Yup. Check da box. :)
    See if that alters anything.

    Andy.
     

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