STM32F030的GPIO操作，寄存器的方式设置IO的输入输出模式，实现扫描法读取按键并控制LED的亮灭。可直接用在STM32F0308-Discovery上。-STM32F030 GPIO operation, register set IO of input and output model, realize scanning method to read the buttons and control the LED light out. Can be directly used on