"READY. Note: When inserting the A4988 module, must be careful not to insert opposite. Stepper motor wiring as follows:
2A, 2B is a group (red, green), 1A, 1B is a group (blue, yellow), if want to change direction, can be change the position of one group , for example 2A, 2B mutually exchanged
UNO for Arduino---expansion board 8 --- EN ( stepper motor driver enable , active low ) 7 --- Z.DIR (Z -axis direction control ) 6 --- Y.DIR (Y -axis direction control ) 5 --- X.DIR (X -axis direction control ) 4 --- Z.STEP (Z -axis stepper control ) 3 --- Y.STEP (Y -axis stepper control ) 2 --- X.STEP (X -axis stepper control )"