Hi
I have a requirement to transmit low rate (9600bps) half duplex data from a PIC
based slave device back and forth to a main controller via a single coax,
preferably via FSK, GMSK etc as apposed to shifting voltage levels as this will
allow us to multiplex other signals onto the cable at the same time.

I have looked into embedded modem devices but the problem seems to be the
conversion from asynchronous to synchronous data. As the UART within the PIC
does not allow access to RX and TX clock lines it makes it difficult to hook up
the single chip modems that I have been able to locate.

There is always the bit banging method, but as the UART is there it would seem
sensible to use it if possible.

Has anybody ever found a solution to this? Any ideas or pointers would be
greatly appreciated.

Regards

Simon