Hello all:

For the next phase of my PIC project (home security), I want to have remote
keypads communicating (only) with the master control unit.  I originally
wanted to use RS232, but was under the impression that RS232 is difficult
to deal with when using long runs (i.e. through a house) and multiple
interface nodes.  For future expandability of the "network", I am leaning
toward RS485, using a Maxim interface chip.  However, I will not run it as
a multi-drop configuration, but as a star-type configuration, with the
keypads running (throughout the house) directly to the master.

My question is:  is my impression of RS232 unfounded?  If so, why?  Has
anyone used RS485 in the way I want to use it?  If so, did you use a
terminating resistor as each node to minimize reflections?  Any other
information you could provide would be very helpful


Regards,

--John