本次课程设计主要实现的是对LED、步进电机和喇叭的控制。步进电机的工作原理是将电脉冲信号转换成角位移的一种机电式数模转换器。步进电机旋转的角位移与输入脉冲的个数成正比；步进电机的转速与输入脉冲的频率成正比；步进电机的转动方向与输入脉冲对绕组加电的顺序有关-The main course design to the LED, loudspeaker and stepper motor control. Stepper motor is the working principle of electrical pulse signal into angular displacement of a Electromechanical Digital to Analog. Stepper motor rotation angular displacement input pulse is proportional to the number; stepper motor speed and input pulse proportional to the frequency; Stepper motor rotation direction and input pulse on winding increase on the order of--