单片机读写U盘源码 基于51单片机和国产USB芯片CH374，挂载FAT文件系统、USB海量存储设备驱动，读写使用FAT文件系统的U盘。-Disk read and write single-chip U-source and based on 51 single-chip USB chip made CH374, mount FAT file system, USB mass storage device driver, read and write using the FAT file