Quote Originally Posted by Bruce View Post
The USART TX pin idles high, so a simple inverter circuit should be all you need to hold the RF transmitters data in pin low during idle periods.

Attachment 4465
Then an inverter will be needed on the receiver side also ???

I still think since you are basically building a transceiver you will want a way to turn the transmitter off when not in use. Does the module have an enable pin?