Question: for the nRF52840, if I configure a GPIO pin as an open-drain output (DRIVE setting of S0D1) and then select this pin as a UART transmit pin, does the open drain setting persist or does the UART peripheral change the DRIVE setting?
Background: I would like to use a single wire to communicate (half-duplex) between a nRF52840 and another microcontroller. My concept was to have an external pull-up on the line and make the UART output from each micro open-drain. I could do this with additional hardware, but it would be nice to do it with a simple pin configuration change in the nRF52840.
I found MartinBL's post in this thread that says the GPIO DRIVE setting affects the pin operation even after the TWI module takes over. However, the post is 2 years old and I wanted to verify that this would apply to the UART peripheral as well.
Thanks!