Finished up my MPCNC PRIMO. Just some notes that things work great with Marlin 2.0.
I have sensorless homing, fine-tuned the default Marlin sensitivity but not by much, and I set my homing current to 200mA. Save me the switches and more important running more wires.
Spindle speed control is with a PWM to 10V converter found in the usual places. I run the PWM from one of the heater headers at 24V on the SKR. Direction and Enable pins from SKR using thermistors, as they have pull-ups, so spindle will be high and hence DISABLED when powering up based on the logic for the controller that came with my spindle.
#define SPINDLE_LASER_ENA_PIN P0_23
#define SPINDLE_DIR_PIN P0_24
#define SPINDLE_LASER_PWM_PIN P2_05
Wish Marlin had a pulse counter to check RPM. Otherwise works great!