THVD1552: Running full duplex transceiver in half duplex mode?

Thanks for the quick answer.  My uncertainty was mostly focused on the part of the question related to tying RE to DE.  Since one is active high and the other is active low, only one node would indeed have an active driver at any given time, but the switchover would essentially be instantaneous.  (However, one or the other driver would be sucking about 0.5mA the entire time...). If you were willing to suffer this power loss, would this work?  I have a shortage of GPIOs.  My MCU is an STM32G4, the USART unit of which gives me a DE, I guess its up to me to either wire DE directly to RE, or to use a GPIO to control RE in software.

Both implementations (i.e., keeping DE and /RE separate versus tying them together) are common.  Some factors to consider are:

 - Does a transmitting node need to be able to receive its own data as it is being sent (i.e., a "loopback" or "echo" function)?  If so, then the ability to have DE high while /RE is low is needed.

 - Does the system need to go into a very low power state where neither transmit or receive functionality is used?  Is so, then the ability to have DE low while /RE is high is useful.

If neither of the above cases apply, then it probably makes sense to tie DE and /RE together in order to save a GPIO.

By the way, I realize one of my earlier statements could have been misread.  When I said that only one node should have an active driver at a given time, what I meant was that at most one node could have an active driver at a time.  It is OK for the bus to be "idle" (all nodes receiving) with no drivers enabled.

Regards,
Max