usbio通信PC端底层源代码，很适合USB初学者的底层驱动学习，配合VB或VC编写的3灯控制简易程序，使PC界面上的3颗灯或下位机上的3颗LED灯随对应的按键或控件动作而变化。-usbio Communications PC-side underlying source code, well suited to the bottom of USB drive for beginners to learn to cope with VB