marlin - How to calculate the Vref and X_CURRENT for a TMC2130 stepper driver, knowing the rated current of the stepper motor? - 3D Printing Stack Exchange
Stepper Calibration: Tune Your VREF, Steps for Perfect Prints! » 3D Printing for Gaming and More
Short tutorial to tuning the Vref of the A4988 and DRV8825 drivers
3D printing guides - How steppers work and how to adjust their drivers - YouTube
Tuning & Upgrading the Stepper Drivers [The Unofficial JGAurora Wiki]