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. Your thoughts and suggestions are appreciated. Phil -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body