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  1. #1
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    serial multiplexer

    Hi all,

    Which is the better way to multiplex the microcontoller serial port. I'm using a PIC with only one serial interface and have to use it to communicate on a 485 network and with a GPRS module.

    Thanks in advance.

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  2. #2
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    serial port multiplex de

    One way is to use a SPI/parallel port to UART converter if the PIC microcontoller has a port free. Else you could use any multiplexer or bus switch that operates at least UART speeds, which is in KHz. As of my Knowledge there are a lot of such devices in the market. The output of the mux/ bus switch would be enabled by the PIC based on the need.



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  3. #3
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    74244 multiplexer

    or maybe i can disable the 485 driver when communicating with de gprs module and use the hardware flow control pins (cts/rts) of the gprs module to disable it when communicating with the 485 network.

    I don't know if it works yet...



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  4. #4
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    serial port multiplexing

    As long as the pins are tristated at the second end it should work. Even multiplexer or bus switch does the same Job. As the GPRS and 485 driver has enable pins you could choose that option. But ensure that the pins of the corresponding pins get tristated when disabled.



  5. #5
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    multiplexing spi port

    hi
    I am doing the serial port multiplexing with 74244 between two devices.
    control pins are enabled or disabled by the micro-controller. software should know about which device needs to be enabled.



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