Thanks, Andy.

Actually, there's nothing to it, really.

Just set up the Rx and Tx routines as shown in the graphic (substitute the pin you're actually using in place of the C.6 I've shown) and call Tx before each transmission, and Rx before receiving (or more accurately, after each transmission).

So, at any time, only one guy is transmitting.

And, make sure the pin you're using is set for digital I/O, of course.

Anand