Chroma blade spectrum no GPS signal

Discussion in 'Blade Chroma Series' started by Tijs Van Puyvelde, Mar 10, 2021.

  1. Tijs Van Puyvelde

    Tijs Van Puyvelde New Member

    Mar 10, 2021
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    Recently my Chroma blade spectrum crashed from very high altitude (no known reason), and broke its GPS.
    I bought a new GPS mast (the big version now: BLH8629) and installed it.
    On the GUI, it now reaches multiple satellites, but whenever I try to start the drone, it is entering smart or AP mode and stuck in this cycle. It will not go into GPS lock.
    upload_2021-3-10_17-51-48.png

    All the other sensors seems to do fine.

    Somebody has a similar experience?

    Thanks in advance,
    Regards
     

    Attached Files:

  2. WTFDproject

    WTFDproject Active Member
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    Oct 3, 2018
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    I'm not sure how many the Chroma requires, but it is usually in the 8 to 10 range as a minimum.
    The image above shows 10 satellites, but only the six in green have good enough "quality" to be used in the calculation. This is pretty typical of being indoors, and since it was attached to a computer at the time, I assume that is where you were.
    Have you taken the Chroma outside, with a clear view of a large section of sky?

    You mentioned you replaced the mast. Did you also replace the GPS unit inside the mast? A new unit will not have an acquired GPS almanac stored. To acquire a fresh almanac, you have to leave the Chroma powered on outside for about a half hour or so. The almanac is broadcast each 12 minutes. It might take a couple of broadcasts before your unit records it. There is also a small battery on the GPS unit that is used only to retain the almanac between uses. A new GPS unit may have been in storage long enough for the little battery to go dead. It takes forever for the little battery to recharge if completely dead. Depending on how low the voltage is, it may take several hours or even a couple of days to recharge it. (Usually a couple of flights is enough.) Until the little battery recharges, the Chroma will loose the almanac every time it is shut down. It charges from the main flight battery when the Chroma is powered up.

    And the bad news. Many, many incidents of GPS failure are related to problems on the flight control board. If it comes to that, the only fix is to replace the Chroma's mainboard.
     
    Tijs Van Puyvelde and Pier2162 like this.
  3. Tijs Van Puyvelde

    Tijs Van Puyvelde New Member

    Mar 10, 2021
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    Thanks for the reply!

    I replaced the GPS unit together with the mast.
    - I have tried the drone outside, but always in between buildings so it could be that it didn't have enough satellites (the printscreen is indeed taken inside)
    - The drone was not yet powered on for such a long time to recharge the battery
    - It also was not placed yet for 30 minutes in the clear sky to acquire the GPS almanac

    Inside the mast, a red LED is blinking, maybe this a signal for the GPS not being charged?

    I'm gonna try this weekend to place it in an open spot for over half an hour.
    I'll keep you updated.
     
  4. WTFDproject

    WTFDproject Active Member
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    Oct 3, 2018
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    There is a red light flashing in the right rear corner on mine, and GPS works fine. It's possible that it may have pattern codes to it, but I suspect it's just letting you know the board is energized.
     
  5. Tijs Van Puyvelde

    Tijs Van Puyvelde New Member

    Mar 10, 2021
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    The problem is solved exactly by doing as you said so.
    Thanks!
     
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