Enable the extra UART on SKR PRO 1.2

Does anyone know how to enable the additional UART near the bottom right of the board, or is it enabled by default? (in the Marlin config)

AFAICT the USB (virtual) serial port is -1, the TFT 1 and the ESP01S port is 6. I could not, however, find out, which one the UART is.

On a related note, does Marlin support 4 serial ports? I know 3 ports was added semi-recently, but I’m planning to add some peripherals to my MPCNC :grin:


That is the serial UART that the RepRap firmware port enables on the SKR Pro for the PanelDue.

I know that you can enable that one instead of the touch screen port… but not sure why you’d do that.

Sorry, doesn’t answer the original question, but at least confirma that the UART works…

Seeing as that is labelled UART3 I think I would try adding -

#define SERIAL_PORT_3 3

to your Configuration.h

It (if it works) will talk at the same rate as serial port 2 ie 115200 or 250000 depending on what your #define BAUDRATE xxxxxxxx is set to.