How to wire up the SKR mini V1.1

On V5 and later versions, the Revolver is not being used anymore, so no stepper driver is plugged into the Y-Motor socket. Instead, this is where you attach the servos for Lid, Wiper and Cutter, according to this instructions. The Revolver endstop is not being used as such and has now become the Relay board control port.

Serial 1 (a.k.a. TFT) is being used to communicate with the 3D printer controller. If you're using the OctoPrint plugin / Klipper extension to control the SMuFF, it's recommended to connect via the USB Serial for convenience purpose and a more stable communication. Since both connectors (USB and TFT) connect internally to the same UART on the MCU, only one of them can be used at the same time. If you attempt to connect and use both, you'll run into communication issues.

Don't forget to setup the MS1, MS2, MS3 jumpers according to the stepper driver you have and the microsteps you want to use. Also, adjust the Vref on the stepper drivers before you attach the stepper motors.

Please keep in mind: This board doesn't support UART driven stepper drivers, such as the TMC2208 or TMC2209. Those drivers will still work but they have to be configured in "Standalone" mode (the old Pololu or A4988 Step/Dir configuration).

EXP1 / EXP2 are being used for the display, whereas it depends which display you have.

The Z-Motor socket can be utilized as an additional serial port (Serial 3) by making a custom adapter. This additional port comes in handy when you need a separate serial communication channel, like for the SMuFF-WI for example.
If you're on a Duet3D controller board and want to pass the JSON data coming from the Duet to the PanelDue, this serial port can be configured to do so in the firmware. The latter option makes the additional SMuFF-Ifc obsolete.