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P2 / H3-3D Memory Defect

Discussion in 'Phantom 2 Discussion' started by ianwood, Dec 5, 2014.

  1. ianwood

    ianwood Taco Wrangler
    Staff Member

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    I've found another defect in the P2 firmware that causes problems in the H3-3D gimbal. If your gimbal has problems with a drifting horizon, this issue probably effects you.

    [​IMG][​IMG]

    Some important things to note:

    • The Phantom 2 supplies inertial movement data to the H3-3D to help it stay level.
    • The Phantom 2 had a change to fix declination offset in firmware 3.06 and up.
    • The 3.06 firmware adjusts compass data for declination offset and remembers it between flights.
    • The H3-3D will exhibit loss of level horizon when the compass data is poor. Videos of TBE show significant loss of horizon in the H3-3D.
    • The H3-3D works normally if used in the same location.
    • The H3-3D will exhibit horizon drift if you take it between areas of different magnetic declination - e.g. from LA to Chicago to NYC.

    Conclusion:

    • Compass adjustments stored in memory by the Phantom 2 are causing horizon drift when the Phantom is used in different areas.

    This has been tested and confirmed on two different Phantom 2 / H3-3D systems. Both exhibit exactly the same behavior. Used in one location, the horizon is consistently level. Once used in an area with a different magnetic declination, the H3-3D will exhibit issues with horizon drift.

    I will experiment with reseting the FC on the Phantom 2 to see if that removes the memory effect on the gimbal.
     
  2. QYV

    QYV

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    I was having this issue, so good to know. Did you do a compass calibration at the new location?
     
  3. ianwood

    ianwood Taco Wrangler
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    Yes, compass and IMU calibrated after any significant travel. Looking for other inputs from other uses who travel and have seen gimbal issues. Also looking for information on reseting the FC safely. I don't want to brick my FC!
     
  4. wkf94025

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    Ian,

    I shoot mostly in Cabo (southern Baja) and Napa Valley, and don't have much of a clean horizon in Napa by which to judge the tilt issue. In Cabo, on the other hand, plenty of blue water horizon by which to judge. Whether science or voodoo, I am fairly religious about using a bubble level and wood shims to set my black case / launch pad up flat and allowing the P2 to face North (approximate) for powering up. Despite religious voodoo startup sequence, I still sometimes get substantially tilted horizon. Maybe 20% of the time? Sometimes simply powering off and back on will reduce/solve the issue. I haven't run enough controlled experiments to determine which factors cause/contribute to horizon tilt. But subjectively, it seems fairly random to me. I travel between Cabo and Napa almost weekly, and don't always recalibrate compass in Cabo. Happy to start tracking/logging details of each flight to help contribute to the body of knowledge and diagnosis.

    How does one reset the FC? You first... ;-)
    Kelly