How to adjust current via VREF on Creality Mainboards

Adjusting the VREF (reference voltage) on your Creality mainboard allows you to fine-tune the current delivered to your stepper motors, helping to resolve issues like overheating motors, missed steps during prints, or excessive driver noise. The adjustment method depends entirely on your mainboard version: boards with A4988 drivers (such as the V4.2.2) require physically turning a potentiometer with a multimeter, while boards with Trinamic drivers (like the V4.2.7 with TMC2208) typically have current set via firmware . This guide covers identifying your board type, locating the correct potentiometers, measuring VREF safely with a multimeter, and recommended voltage ranges for X, Y, Z, and extruder axes.

TABLE OF CONTENTS

• Written Guide: 
  • How to change the Current using Vref
  • Example:
• Video Guide: 

Written Guide: 

How to change the Current using Vref

Reading the current supplied to stepper motors can be challenging. To determine this current, we utilize the Vref value, a voltage reference measured in VDC, which can be obtained using a multimeter. This value is crucial for setting the output current of the stepper motor driver.

Different 3D printer mainboards employ various stepper motor drivers, and each type has its own formula for calculating the required Vref to achieve a specific current. Here are a couple of examples:

• TMC stepper drivers.
  The formula for these drivers is Vref = ( I * 2.5 ) / Imax
  Where I is the target current value measured in A; and Imax is 1.77 on regular mode and 1.2 on SilentStepSticks mode.

• Pololu A4998.
  The formula for these drivers is Vref = I * 8 * R
  Where I is the target current value measured in A; and R is the Sense Resistor value, that depends on what board are you using. Melzis use 0.1,the Creality Silent boards use 0.15, ...

Example:

For a desired current of 0.5A, the resulting Vref would be 0.6V on a Creality A4998 board.

0.5 * 8 * 0.15=0.6

Video Guide: