Power Source Problem / Data-only Cable?

  • Hey Everyone,


    I'm still working on getting things set up and I think I might have a power source problem. Here's my rig:


    Pi Zero

    ZumYu HDMI Video Capture Card 4K

    WS2812B LED strip


    I've wired up a mini USB hub to connect my Pi to the network via ethernet (near the TV is a weak wifi spot) while using the main power supply. However, it seems that sometimes the capture card will pull power from the intended data connection rather than its own dedicated USB power connection. When it does so, the HDCP image will flicker, likely due to intermittent incoming low power.



    This also happens if I try connecting directly to the Pi.



    If I plug USB connections in using a "correct" order, the system works flawlessly.


    Is there a way to force the video capture card to only pull power from its dedicated power source? Can I create a "data only" USB cable by clipping the power lines between the video capture card and the Pi or are the power lines needed for data transfer?


    Just checking before I sacrifice another USB cable.


    Thanks again for your awesome help!!


    Phade.

  • Zur hilfreichsten Antwort springen
  • Hi Guy,

    first of all, you use a USB 3.0 Video Capture Card at a USB 2.0 Port (PiZero). Too low data flow...? Maybe.

    I think a USB hub for power is not a good idea. I see your capture card has an own Type-C port for power. Try this.

    Some cards take her current also over HDMI. Electrical current always looks for the shortest route. I think that's the problem.

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

  • Hey Mike,


    Thanks for your reply!


    Ya, I'm trying to avoid the red lines in the diagram and asking how to prevent them. I have both the USB-C and USB-A cables connected, but I want to force power through USB-C and prevent power from USB-A. Will cutting the USB-A power leads still allow data to work through USB-A?


    The data rate between the capture card and Pi is working fine; it's the HDMI signal to the TV that blinks out every once in a while if the device is not connected in the "correct" order for power allocation. I have a 1080p signal going through the HDMI ports (I got a 4K card for futureproof-ness) and the USB capture setting is set to a minimal widescreen resolution.


    Phade.

    • Hilfreichste Antwort

    Will cutting the USB-A power leads still allow data to work through USB-A?

    :thumbup:Should be no problem. Cut only the red wire (+5V), black, green and white must persist.

    I have also 1080p equipment and Live Streaming Videoaufzeichnung Unterricht Videokonferenz Live Rundfunk works fine for me.

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

    2 Mal editiert, zuletzt von Mike72 ()

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