Finally I got it working properly. Reading SDcard was very awesome for me for first time, so I decided to make a library for STM32F4xx devices and post it to my website. It’s basically just communication interface between STM32F4 and FatFS library by

平衡小车，两个步进电机，加驱动器、好好学习，天天进步，加油(every night in my dreams i see you, i feel you, that is how i know you go on far across the distance and spaces between us you have come to show you go on n.)

stm32f10x adc驱动代码，自己写的，在项目中已经使用过，可以运行。(Driver for stm32f10x chip's adc module, I have used in my project.)