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FDC1004: how to enable read-out of 12-channels with FDC1004

Alex Semeniuk
Intellectual 300 points
Part Number: FDC1004
Other Parts Discussed in Thread: , MSP430F5528, FDC2214

Hello friends,

I need to read out 12 channels with FDC1004EVM (or with  just FDC1004 chip), which has only four inputs.

Could you please recommend the best way of how to set it up.

Thank you in advance,

Alex

  • 0
    TI__Genius 17440 points

    Hi Alex,

    To measure 12 different channels you'll need 3 FDC1004 devices. Each FDC1004 will need its own I2C bus, because it only has one I2C address. You can also use an I2C expander if you need to conserve I/O pins on your MCU. You could potentially connect the I2C expander to the MCU side of the FDC1004EVM, but it might be easier to start from scratch with a new PCB (or even a breadboard for quick experimentation). You would also need to write custom firmware to read from all of the devices, but you should be able to leverage this sample code. 

    Regards,

  • 0 in reply to Kristin Jones93
    Intellectual 300 points
    Hello Kristine,

    Thank you for the sample code. Would you recommend any particular TI MCU and I2C expander for
    this project (preferably already mounted on the breakout board:) ?

    In the link below they used FSUSB74 multiplexer with MSP430F5528 (same as on FDC1004EVM).

    www.ti.com/.../TIDA-00509

    Should they work with FDC1004 as well?
    For our project, the sensitivity is crucial.
    I tried running FDC1004 with arduino uno, but got too much noise in comparison with FDC1004EVM.
    This clearly indicates the importance of the right components.
    Please advise,

    Kind regards,

    Alex
  • 0 in reply to Alex Semeniuk
    TI__Genius 17440 points

    Hi Alex,

    I would definitely recommend modeling your schematic after the TI Design you mentioned. Unfortunately TI does not make I2C expanders, but both the MCU and the multiplexer used in the TI Design should work for you. The MSP430F5528 is the MCU used in all of our EVMs and demos, including the FDC1004EVM. 

    If sensitivity is extremely important to your application, I would also recommend that you experiment with the FDC2214, which is more noise immune than the FDC1004. 

    Regards,

  • 0 in reply to Kristin Jones93
    Intellectual 300 points
    Great, thank you)

    Alex