Communications between 2 or more units.

Hi ..
I have been developing my own home controller for heating .
But now i must make my system bigger ..
Then i had thoughts of how to communicate between these units should work .
Is XIN and Xout between units a good way of doing it ??
Or should i chose serin and serout for this ...
I am planning to make one "master unit" and one in-module and some
out-modules.
Does anyone have some advice ??
// Nizze

how bout rs485 networking

hansknec made an earlier post about networking pics. He uses them to drive stepper motors. He posted code and pseudocode. It's not exactly your application but it's worth looking at. You'll need to scroll down almost to the bottom of the page.

http://www.picbasic.co.uk/forum/show...light=hansknec