When the MKS TMC2208 driver is used in normal mode, please keep the 3 subdivision jumper caps of the motherboard. The pulse is calculated according to 16 subdivisions. The internal difference of the chip: the division is automatically extended to 256 subdivisions. measuring: current must be converted by measuring voltage, the of measuring voltage Vef, and the voltage between the knob on and the shell (gnd) of the USB interface, which is regarded as Vref. current can be converted by Vref through different drive conversion formulas. Adjustment: Vref can be adjusted according to the operation of the motor, and the knob above can be driven by adjustment (clockwise increases, counterclockwise decreases) note: Before adjusting the knob, it must be carried out under the condition of power off. After the adjustment is completed, perform power-on measurement to prevent or the motherboard from burning out. Drive current algorithm and adjustment 1. Vref measures the voltage at Gnd and the middle end of the potentiometer. 2. Be sure not to connect the motor when measuring the voltage, otherwise will be easily burned. 3. The power supply should be connected when measuring the voltage, and do not just connect to the USB power supply. Please pay special attention to the direction, do not insert it backwards! Instructions 1. When using on the printer control board, please keep the 3 jumper caps under the socket 2. Pay attention to the direction. 3. Can be used for MKSSGEN_ L, no need to weld the pin header 4. The direction of the motor is exactly opposite to 4988 and 8825. If you want to replace 4988 directly, please adjust the firmware or adjust the motor connection. size:10*10cm Material:pcb colour:Black + white Package Contents: 1 * TMC2208 stepper motor driver 1 * heat sink 1 * screwdriver Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.