硬件构成：lpc2219+D13 软件功能：利用arm做主控，采用d13与usb接口做主机，通过主机向u盘中写入文件，当写文件完成后响铃提示-hardware : lpc2219 D13 software functions : the controlling arm, d8 using usb interface with the mainframe done by the mainframe to u sites writes the document, when the documen