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  1. #1
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    USB Hubs with FDTI is not working

    Dear all,

    I have solved lots of my problems here and I am stuck again in one situation.

    I have a terminal pc with 2 usb port and I need to expand usb and need to convert rs232. One hub has 4 usb connector and other one has 5 ftdi232rl to convert usb to rs232.

    Terminal uses GL850G to expand usb on terminal.

    I designed to board because of limited area. and connected one above the other. and made the 8 pin connection between them for data lines and 2pin power supply. My problem is they are not working correctly.

    I assemblied 3 board and I have 3 different situatin on them. Fisrtly I connected the board and pc saw the USB hubs but did not see the ftdi converters. Second board saw the 1 hub with ftdi converters. and last one saw the only one hub with usb connectors. I also tested the first board which saw the 2 hub something like this, I removed one ftdi chip because I read something enumeration of the FTDI chips and but it did not see the other ftdi chip. only one chip was connected to boards.
    I supplied them from therminal and external supply but nothing changed.

    Could you please help me about this situation.

    Thanks
    Best Regards

    Here are the schematics
    Board 1.pdf

    Board 2.pdf

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  2. #2
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    Re: USB Hubs with FDTI is not working

    Sure the connection of pin 17/19/26 is correct? Which schematic are you referring to?



  3. #3
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    Re: USB Hubs with FDTI is not working

    Hi,

    VCCIO is not connected
    RESET is not connected


    Klaus



  4. #4
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    Re: USB Hubs with FDTI is not working

    Dear FvM, I found a schematic on web and I made whole thing according to it.

    KlausST, what should I connect them, 5V or any other voltage?

    Thanks for your replies.
    Best Regards.

    Hikmet



  5. #5
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    Re: USB Hubs with FDTI is not working

    Hi,

    KlausST, what should I connect them, 5V or any other voltage?
    If I had to decide this, i'd look into the datasheet.

    Klaus

    - - - Updated - - -

    Added:

    Generally: Don't leave any signal input floating.


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    Re: USB Hubs with FDTI is not working

    FT232R RESET can be unconnected in bus-powered application, VCCIO must be connected either to 5 or 3.3V, in your design obviously 5V.

    I don't know if missing VCCIO blocks device enumeration. I also don't know if the shown FE1.1s schematic is correct. Having it picked up somewhere from the internet doesn't actually answer the question.


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  7. #7
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    Re: USB Hubs with FDTI is not working

    Dear FvM FE1.1s circuit is correct I have corrected it with the manufacturer. I did not connected the VCCIO.
    KlausST told me to look datasheet for the VCCIO and Reset connection and there is a voltage divider with 4.7K and 10K resistors. So it gives 3.3v to Reset pin.Also VCCIO is connected to 5V supply and I made a test like that, I mean I connected 4.7k and 10k to reset and Connected a wire between VCCIO and VCC, it worked.

    Thanks for your help KlausST and FVM.



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