【摘要】 U SB总线是计算机外设接口的发展趋势,越来越多的设备使用U SB接口代替RS 232接口。区别于传统的RS 232总线控制投影仪的通讯方式,提出了一种方案,将RS 232接口转换为U SB接口接入PC机,使用U SB总线控制投影仪工作,使系统具有了U SB总线方便、灵活的特点。在系统实现过程中,PC机对设备的识别和控制投影仪命令的传输都由固件完成。另外,文章分析了U SB总线的通信原理,同时研究了系统软硬件设计方案。更多还原

【Abstract】 The USB Bus is the trend of computer peripheral interface and many devices have USB interface instead of RS232.Different from the traditional control system for projector that uses RS232,the new method convert the RS232 interface to USB that is used to control the Projector,and makes the system has the features of USB Bus such as facility and smart.The function of the fireware is to identify the device and achieve the data transfer.This article analyses the principle of USB communication and also designs the hardware and software.更多还原