Feature: Stepper motor driver board with ULN2003. A, B, C, D four-phase LED indicates the status of the stepper motor work. Stepper motor with a standard interface, when used directly pluggable. 5 Line 4 phase can be driven by ordinary uln2003 chip can also be connected in phase 2 development board. It's used for supporting the use of a direct plug and easy to use stepper motor used in the development board.