Simple, direction and enable based stepper tester for BTT SKR V1.3 and V1.4
Moves all stepper motors back and forward repeatedly. Assumes active low stepper driver enable pins. Uses fan0 port as a LED to indicate activity.
Pre-built binaries are in the prebuiltbins directory. If you don't want to build you can just just copy the appropriate firmware.bin to your sd card and reboot the controller with the sd card in the controllers sd card slot.
