在编程软件的配合下，要求实现如下功能:单击K1，控制步进电机正转；单击K2，控制步进电机反转，连续按K1、K2，步进电机可连续旋转。(In cooperation with the programming software, it is required to realize the following functions: Click K1 to control the forward rotation of the stepper motor; click K2 to control the stepping motor to reverse and press K1 and K2 continuously. The stepping motor can rotate continuously.)