在JX44B0实验箱上实现功能键盘1实现步进电机正反转，2为使能键，3使步进电机加速转动，6使步进电机减速转动，9为退出键。-In JX44B0 test box to achieve realization of the stepper motor function keyboard 1 inversion, 2 to enable key 3 rotate the stepper motor acceleration, deceleration turn the stepper motor