On Mon, 24 Feb 2003, Phil wrote:

*>What would you suggest for serial communications between PIC's
*>(16F877/876's) that are located about 200 feet (60 meters) apart and on
*>Cat 3 (or if I am lucky Cat 5) cable?  The data rate is slow, much less
*>than 1,000 bps.  I have looked at I2C but it appears to be limited to
*>only a few meters.  Did I miss something in the spec that allows it to
*>operate at longer distances and reduced data rates?
*>
*>I would prefer a "daisy-chain" interconnect but if necessary a star
*>topology could be implemented.
*>
*>Is it time for a roll-your-own interface?  Currently I am not I/O
*>limited but that may change :~)
*>
*>Data, Clk and Vss would seem to be the easiest and minimum number of
*>signals.

Send RS232 modulation using RS485 interface chips.

Peter

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