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R/C Freq Interference?-Drunk Inspire!

Discussion in 'Inspire 1 Help' started by tweaker, Apr 24, 2015.

  1. tweaker

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    Flying on latest Firmware today (safe to fly gps)when filming a wind turbine in a local quarry.
    First ten mins or so all good then a/c displayed "mc data error"
    Warning went off the a/c flew as if it was drunk!My input was hardly being recognised.Very hard almost impossible to control.
    Initiated RTH but now no gps signal.
    Switched to atti still same symptoms got it down PDQ.!!
    A/C flipped stoved in albeit not full force(controlled-ish forced landing)
    Foreign body ingest into rear motors only real damage was broken props.
    Just trying to analyse why?
    Quarry use two way radios?
    Quarry have trucks-CB Radios?
    Quarry use a wireless for machinery?
    I thought inspire frequency hopped frequency and if frequency dropped it RTh?
    Needing to learn lessons to prevent re occurrence of near heart failure!!!
    Any thoughts gladly hoisted on board
     
  2. The Editor

    The Editor Moderator
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    MC Data error is just the flight log full - This will clear out upon rebooting the AC so nothing to worry about there (just a bit disconcerting the first time you see it flashing red in front of you!)

    To answer your other question as to why it was flying erratically, please advise whilst doing you pre-flight checklist, what were your IMU mod values?

    Gyroscope.
    Accelerometer.
    Compass.
     
  3. tweaker

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  4. tweaker

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    Cant remember exactly.

    After compass calibration I went to do IMU calibration and it said it was not required or words to that effect.

    Thanks for prompt reply.

    Further info-once I forced landed changed and changed props-I took off again
    To test nothing was damaged and a quick function test stayed at 4-5m alt and a/c seemed to slightly toilet bowl.
    After function test decided to land as I wad not confident my 2.4ghz signal was being disrupted etc and a repeat perfomance was not imminent.
    What I am saying I lost my bottle!!!
    I think the a/c 2.4ghz signal was being "corrupted" with other signals in the quarry.
    Need to get another flight this afternoon to test theory....
     
  5. The Editor

    The Editor Moderator
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    If it was toilet bowling then likely a compass error which can make the craft fly 'drunk'

    Highly unlikely to be control link interference as the Inspire uses frequency hopping spread spectrum technology and every data packet transmitted and received from/to the aircraft has a unique 'identifier' and checksum prefix attached to constantly check for data stream errors and interference etc.

    Much more likely to be a bad compass calibration or IMU error.
     
  6. tweaker

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    Thanks again for prompt response just trying to understand what I saw and avoid a repeat of!!

    Compass calibrated before flight and just assumed as the A/C said IMU did not have to be updated it was fine.

    Just re confirm for me(as I am now confirming and double re confirming all that I thought was true!!) what acceptable tolerances are in IMU Check

    Will be totally anal with IMU Check in future......

    Every days a school day
     
  7. amkorp

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    Toronto, ON / Buffalo, NY

    I've seen The Editor mention this in SEVERAL threads, and I agree with him 100%. Everyone should be adding IMU MOD value check to their pre flight list. Such a simple thing can be very helpful before you take off as well as if you need answers as to why your aircraft behaved abnormally during flight.
     
  8. tweaker

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    Finally back in and reviewed my footage recorded on Nvidia Shield.

    My compass values where sitting at 800!!

    Now I know to check IMU values which I did do but because I performed a compass calibration before hand and it was successful when I opened up the IMU window I MISSED that it should be 1500. I can't believe that I looked at it and didn't see it!!! I mean I know what the values should be but I had a doh moment that luckily turne out ok in that there was no lasting damage to my A/C,pride(no one saw the erratic flying ) and most importantly no infrastructure or people hurt/broken.

    Thanks for feed back and I have learned in a perverse way from today

    1. Do not rush to get a/c airborne

    2. Print off pre flight checks,fable and stick to outs side of peli case

    3. Record on tablet as well as a/c to "after action review" flights both good and bad. Really good to see EXACTLY what was going on during flight-things to improve on,what went well etc etc

    Had a test flight later on today albeit with initially shaky confidence!! A/C sweet as a nut after IMU Calibration/Compass Calibration.

    Only problem I have is now I can not set RC Location as home point. I get message "weak RC GPS signal,cannot acquire location info". The a/c will land using its location as home point when RTH Button is pressed but will not return to the other RTH Point. Any ideas?

    Once again thanks for timely help with my drama today especially to the editor who was like greased lightning in his reply after my post.
     
  9. The Editor

    The Editor Moderator
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    Glad you got things sorted - and yes 800 for a compass mod value is way too far out of ideal range :eek:.

    The dynamic home point setting/weak GPS is a bug in v1.2.1.0 and is being looked at. In the meantime you will get this error when ever you try to set it.
    For the time being, as frustrating as it is - do not use dynamic home point.
     
  10. tweaker

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    Great Thanks.

    Will remember dynamic home point-no flights over water for a bit then!!

    Love this "Copter Stuff" even with all the mishaps!!!

    If things are to easy then generally they are not worth it-cannot remember who told me that.

    This forum is a top resource and its good that everyone stays tight and helps the other guy if they can.