So I know the catch is that only one device can use the tx and rx lines. I have two devices that require serial tx/rx communication. Is there a way around this problem? I was thinking a switch that can be switched on/off with one of the other digital pins? Thoughts? Thanks in advance.
Well, the Uno can Tx to both at same time.
Need a way to only Rx from one at a time.
What voltage levels are being used? TTL? RS232? RS485?
With TTL, you could use a pin as you suggested to enable one Rx line or the other thru their own 74HC125 buffer.