利用stm32f407作为测试板的，功能为利用硬件I2C来驱动OLED。里面有字库，但是字库是网上拷的并不是自己制作的。-Stm32f407 use as a test board to take advantage of hardware I2C functions to drive OLED. There are character, but character is the online copy is not to produce their own.