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lightbridge + P2 - no telemetry data

Discussion in 'DJI Lightbridge' started by gaucho, Apr 14, 2015.

  1. gaucho

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    CASE DESCRIPTION
    the phantom 2 is connected to a lightbridge.
    the ground lightbridge is connected to futaba T8FG for commands (by means of the training port)
    the ground lightbridge is connected to android smartphone for video and telemetry display.
    I can fly and control the phantom2, so commands are flowing from the futaba to lightbridge and finally they arrives to phantom2.
    I can see on the android phone the quality of the received images, so video is decoded from lightbridge to android phone.
    THERE IS NO CAMERA ATTACHED TO THE VIDEO SOURCE IN BECAUSE THE ORDERED GOPRO CAMERA STILL IT IS NOT ARRIVED)

    PROBLEM
    I can not see on the android phone the available battery charge, the radio channel quality, the heading of the phantom. It seems that telemetry is not arriving on the android phone.

    NOTE
    all components are updated to last available firmware revision.

    REQUEST
    Could we dentify and solve the problem?
    How could i know if the flying part of the lightbridge is receiving the telemetry data from the phantom?
    Could i connect to it with some tool? the assistant software has no information about telemetry.
    I'm electronic expert, i can follow also complex procedures. Feel free to ask to me whatever you want at my own risk.

    i checked the lightbridge cable with multimeter, it seems ok.
    I also tried to connect the usb to lightbridge and then to open hyperterminal to see what it prints but i was not able to obtain usable information.
     
    #1 gaucho, Apr 14, 2015
    Last edited: Apr 19, 2015
  2. mohan

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    There is only 2 cables to connect to the phantom

    1. Control wire - 2 wires connecting to Naza controller. This is ok as you are controlling phantom
    2. Black cable which feeds video and telemetry. Either your cable is faulty or there is a fault in the Lightbridge air station.

    On my LB as soon as I get video I get telemetry
     
  3. gaucho

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    Is it there a method to understand if naza sends telemetry?
    Is it there a method to understand if lb receives telemetry?
     
  4. mohan

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    You need to buy mini iosd and hook the video feed to a monitor. mini iosd is relatively inexpensive
     
  5. gaucho

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    dear mohan, thank you for your support.
    yes i could buy mini iOsd to check if naza is sending data, but if i can i will prefer to don't purchase it.

    (within 2 weeks i will have back from my friend a miniosd, i don't know if it works also with phantom; now my friend uses it on a ardupilot).

    NEWS: today i had 2 news:

    1) the german support said that there is a flag to enable data on the lightbridge but i'm not able to find any flag on the assistant.. i'm going crazy..

    2) i connected a A2 flight controller with a brand new lightbridge and the result is exactly the same: i can send commands from the radio to the A2 but i'm not able to receive telemetry on the android smartphone.
     
  6. gaucho

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    finally I found the solution by myself:
    I could do a test with a camera (the one that i ordered still didn't arrived)
    I found that: without video source the lightbridge transmits empty video frames (and it shows their quality), but the telemetry information are not sent. As soon as the lightbridge reveals the video source, it starts to send the telemetry information. The telemetry stays enabled even if you later disconnect the video source.
    So there was no problem.. you just need to know this fact (or to write it somewhere on the manuals)I
     
  7. ianwood

    ianwood Taco Wrangler
    Staff Member

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    This is most likely because the telemetry is encapsulated in the video stream. LB doesn't transmit audio so likely it's taken over the audio channels for telemetry.