U盘文件读写模块, 连接方式: 3线制串口+查询，因为使用U盘文件读写模块而不是使用U盘文件级子程序库,所以占用较少的单片机资源。-U disk read and write files module, connection: 3 wire serial+ query, because of the use of U disk file read write module instead of using U disk file level subroutine library, so less computer resource.