STM32 signalling for RS-485 - DE?

[Justin1]

We are using the STM32F091RC to setup an RS-485 interface with the TI SN65HVD11. How do we connect to the DE control signal for the SN65HVD11?

I have currently selected USART3 -

• R - PC5 (RX)
• D - PC4 (TX)
• DE - PB1 (RTS)

Is this correct? Also what is CK_RTS, I could not find a pin description.

[Tesla DeLorean]

CK_RTS, pin that acts as clock in sync mode, and RTS in async ? Block diagram of USART should be illustrative.

DE needs to be high when transmitting, you could presumably use a GPIO if RTS doesn't drive for whole byte time, you'd want to review the Reference Manual, not actively using F0 parts here. Could also confirm with scope of TX vs RTS in the RS485 compatible mode.