Home Page Forums Raspberry Pi Shields use GPIO pins instead of the USB port on the 4G/LTE Shield Kit

This topic contains 6 replies, has 4 voices, and was last updated by  mikehotel 2 months, 1 week ago.

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  • #38868

    michele.bagarin
    Participant

    Hi,
    is it possible to use Raspberry’s GPIO pins instead of the USB port on the 4G/LTE Shield Kit?
    Thanks

    #38921

    Saeed
    Moderator

    Yes, It is possible but not recommended. This will limit your connection speed.
    You will need to solder/bridge the UART resistor pads available below the shield.

    #38922

    michele.bagarin
    Participant

    So if I have the long header do you mean to bridge pins 8 and 10 in this image?
    pins
    and in the installation process what PORT name do I need to enter?

    #40701

    mikehotel
    Participant

    Hi Michele, not sure if you’ve solved this yet, so apologies if you have. If you look at the underside of the 4G shield, near the header block you should see four pads labelled ‘UART Resistors’. I believe it’s these need to be bridged.

    Also, did you get an answer about what /dev/ttyXXX interface to use? I would like to know this also.

    Thanks

    • This reply was modified 3 months, 1 week ago by  mikehotel. Reason: typo
    #47305

    michele.bagarin
    Participant

    So it has nothing to do with the header, there are 4 UART resistor pads, do I need to bridge them all together?
    I didn’t get an answer about what interface to use

    #47314

    Dave Matthews
    Participant

    I am douing a similar thing, Using the Quectel Eval board everything works as intended, but replacing this with the 3G-4G/LTE Base Shield V2 and it doesn’t register the SIM card, I have tried soldering 330 ohm resistor across the UART pads with no success. Does anyone know the recommended value of the resistors and am I correct in thinking they align in parallel to the header socket?

    #49459

    mikehotel
    Participant

    Hi Michele/Dave, With the GPIO block along the bottom edge, if you look at the tracks on the board that lead to/from the UART pads. It appears as though the top left and top right pads should be joined together and the bottom left and bottom right pads should be joined together. I don’t believe there should be a connection between top and bottom pads as they appear to be two separate tracks on the board. From the response from Saeed (see above) he didn’t mention any in-line resistors being needed, so maybe just a solder bridge or wire link should work.

    It would be nice to get confirmation before modifying the board. 🙂

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