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GPS loss issues

Discussion in 'Cinestar Misc' started by Dave King, May 6, 2013.

  1. Shaun Stanton

    Shaun Stanton Active Member

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    Colin

    One things I noticed is that you took off with both hold modes on. In practice I don,t think its a good idea. Because of the issues you have experienced. You never know when your GPS may burp on you and could command the aircraft to do something stupid like crash into you. As for the altitude hold, with the old system you could get away with it but they explicitly recommend to take off and stabilize. Even if you have the old system, you never know when that sensor could get an erratic reading, especially low to the ground. Some systems may allow for the hold modes to on, but MK does not really do a good job. The only time I will let the autopilot land is if I have to in an emergency. Either a lost link situation where I have no choice or a low battery where i will put the hold modes on and find a clearing and hope get it to the ground before it shuts off. Ideally its been general practice in aviation to stabilize the aircraft then put the auto pilot on one mode at time so you can react if it does something weird. If something happens on takeoff you might be in trouble. I usually takeoff put the A/C to 20 feet then AH on if I need to use it. Its something to consider since these systems are not redundant and have proven to not allways work as advertised.
     
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  2. Dave King

    Dave King Well-Known Member

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    Very helpful and my mind is spinning. :confused: o_O
    Going to book mark this page for reference. Great info.
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Don't worry, Dave. Nobody really knows what time is, so it's hardly surprising that nobody knows how to measure it! :)

    Andy.
     
  4. Colin Snow

    Colin Snow Active Member

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    Thanks Shaun. I'll check that out.

    Not true. Check out the data again. Look at Altitude not Elevation. I turned on AH at ~10ft and PH later.

    Colin
     
  5. Shaun Stanton

    Shaun Stanton Active Member

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    My sorry I was looking at the OSD and saw it on. I did not scroll through the actual data lines. Disregard ;)
     
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  6. Colin Snow

    Colin Snow Active Member

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    The battery was bad and I ordered one here: http://www.mouser.com/Search/Produc...virtualkey62800000virtualkey628-MS621FE-FL11E

    Unfortunately while attempting to replace it I ripped the positive solder point complexly out of the board. My Facebook post for that day reads:

    Replacement button battery for my kopter's GPS navigation board - $2.10. Replacement GPS navigation board because I broke it while soldered the battery on - $137.30​

    Colin
     
  7. Shaun Stanton

    Shaun Stanton Active Member

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    That sucks, Yeah I hate these things a little stupid component becomes unsoldered and your screwed. The GPS still should be functional it just will take forever for the satellites to acquire. I use some benched batteries that are no longer flight worthy, to plug in the copter for hours once a week to allow that little battery to get a good charge.
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Can you post an image of the damage, Colin -- it might be possible to use some very thin wire-wrap wire to rebuild the trace. I have some that I can pop in an envelope if you don't want to experience the full on, close range, Fry's Electronic experience.... :)

    Andy.
     
  9. Colin Snow

    Colin Snow Active Member

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    Hi Shaun - Yes the board was still functional but like you said it took forever to acquire. Can you explain how you use those batteries? Do you just plug in the whole kopter? If so, how do you stop the beep?

    I have also heard that you can plug in the USB to overnight. Anybody tried that? Which connection point?

    Hi Andy - Here's a pic. Thanks for the offer , but IMHO it's not worth the effort. As you can see there are other "user induced anomalies."

    Colin
     

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  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Thanks Colin (nice image!)
    It might still be possible to repair that board, but that's your call.
    To charge the battery up, power the copter up with the main flight LiPo and just let it sit. As Shaun says, all it does it provide battery backup to the last known GPS coordinates to save time the next time you power up the GPS board.

    You can use MK Tool to check the GPS board and whether it's operating correctly even without that battery.

    Andy.
     
  11. Shaun Stanton

    Shaun Stanton Active Member

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    The USB will work as well. I have my bird in the garage so I just plug in a standard main Lipo to the system and disconnect the Buzzer that I use a JST for, so that way its not chirping the insidious lost link beeps because the RC controller's off.

    I never tried connecting the USB directly to the GPS, I suppose if it lights up its getting power. It is low powered battery it doesn't much to charge it, hence why it goes bad if left unattended for a long periods of time.
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    If your copter's buzzer doesn't have a connector, just go into the firmware upgrade window without actually doing the firmware upgrade -- it stops the beeping.

    Andy.
     
  13. Colin Snow

    Colin Snow Active Member

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    Hi Andy. Thanks. I am not going to attempt that repair.

    I replaced the board with a new one (soldered the shield on no problem) and recalibrated the compass. I flew and had no problems. It acquired SATs right away and I confirmed PH and CH. However, when I use MK Took and click on the MKGPS tab Ms. Graupner says "Error GPS". Pic attached of that screen. Did I miss a step in the replacement? Any idea where to look / what to do next?

    Colin
     

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  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Did you by chance get a GPX file? Just curious as to what error flags it might be showing -- it seems contradictory that PH would be working fine without a GPS....

    Andy.
     
  15. Gary Haynes

    Gary Haynes Administrator
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    Colin how are you connecting to the copter with MKTool? If wireless your screen shot is normal. You likely will not see the bars but the right side does show you have sats and signals.
     
  16. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Good point, Gary. I'd forgotten that you had discovered that anomaly. I also connect by hard-wire so didn't think to ask.
    Thanks
    Andy.
     
  17. Colin Snow

    Colin Snow Active Member

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    There were no errors at all on the GPX file. I connected hardwire through the OSD board. That is how QC has instructed and labeled. But I just tried direct through the Navi Board and I get this image and now a spoken "Error GPS" voice when there are less than seven SATs. I was thinking it would make sense to here an error if it was than six. Even so, why the message?

    Colin
     

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  18. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Can you confirm that you downloaded the most recent MK Voice file into the Graupner, please Colin.
    I'm pretty sure it's this one: http://www.mikrokopter.de/ucwiki/en/HottUpdate

    In the past, I've some mismatched voice announcements if you don't have the correct voice file.

    Thanks
    Andy.
     
  19. Colin Snow

    Colin Snow Active Member

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    Hi Andy

    I was down rev on the mx-20 so I updated and now at 1.171. I loaded the English_Mikrokopter_V2.vdf file.
    Strange on second power up (after an hour) I had to re-bind.

    So, I still get the same "Error GPS" when I access that tab in the MKTool and there are less than 7 satellites acquired. The message on the bottom of the mx-20 screen is 05:GPS communicatio [sic].

    Also, for the first few times I did not hear the voice say "Mikrokopter" (or anything else) when powering on the kopter. However, I do see the work Mikrokopter it on the telemetry screen(s). It works now and I take great comfort for the same random bug I had before with "Altitude On" or "GPS Home" spoken on power up also (even though they are off).

    Colin
     
  20. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    In Mk Tool, there is a setting for a minimum number of satellites to acquire before takeoff. What do you have that set to?
    It's on the Navi-Ctrl Tab, "Min. Sat." On mine that's set to 6.

    Not sure about the lack of Mikrokopter voice -- I do think the MK voice technology might have a slightly uneasy relationship with the Graupner radios.

    Andy.
     

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