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Logical Channel detection

  1. Dec 23, 2014 #1
    I am designing a PCB with multiple 2-pos DF13 connectors in it (Like 50+).
    at the end of the board there is a 10 pos. cable.

    My intent is that the user (me) connects up to 9 channels in any position I like (I have 50 possible choices). However, this board is connected to another PCB that runs on DV connector that can only read 9 channels.

    I wanted to know if there is a simple way to have some sort of logic IC (or maybe some other simpler way?) so that 9 channels get routed into the output of the board. Also, if there is a way for this IC to always number them in the same way (say top left is no. 1 , and go incremental row-wise or column-wise).

    That way I can know which channel is which and I wont have to be testing each one everytime i use a different combination of positions (out of the possible 50).

    Im assuming it is related to how TVs work (using a giant matrix of pixels) but this is a very small matrix of sensors that might or might not be in use.

    Thank you!

    Attached Files:

  2. jcsd
  3. Dec 23, 2014 #2


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    How does the circuit know which channels are used? Do you program it? Do you have to change that frequently?

    50-->9 can be done with 9 multiplexers, and if you can program them you can get every possible routing.
  4. Dec 24, 2014 #3


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    What are the channels conducting, and what is permissible in the switching array? Are you switching Logic, analog voltage? analog Current? As you scan the inputs, how might you tell whether something is connected? Can you program a micro controller to scan the array and make decisions? Does it need to remember the settings through a power down? Are you switching 1000 volts? 200MHz? How fast do you need to decide? ETC ETC ETC

    What are you really trying to do?

    There is much you have left out that makes it impossible to answer.
  5. Jan 5, 2015 #4
    Each channel has a thermistor in it, so it only reads resistance. So analgo voltage I would assume.

    Yes i could add a micro-controller to scan and make decisions, however I would like to keep it as simple as possible. I am looking for the simplest solution.
  6. Jan 5, 2015 #5


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    again you fail to adequately describe what you are actually trying to do. Nothing about the selection process, how you want it to work. Try drawing a diagram with switches that show selected and unselected channels and where the control information comes from.

    It may be that a uC IS the simplest, but it's hard to be sure with no real specification.
  7. Jan 6, 2015 #6


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    There are commercial mechanical switches with relays. I guess electronic multiplexers don't help if you want to measure resistances on those channels.
    Where is the "logical"?
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