mega128+ch375实现读写u盘功能iccavr源码，支持fat32格式-mega128 ch375 achieve disc read and write function u iccavr source, support fat32 format

SD卡文件格式读取工具，FAT32文件系统格式查看非常方便-SD card reader tool file format, FAT32 file system format is very easy to see

STM32使用硬件SPI接口读写SD卡并移植上开源的FATFS文件系统以实现SD卡按FAT32文件格式读写。-STM32 hardware SPI interface SD card reader and transplanted on the open source FATFS file system to the SD card FAT32 file format reader.