基于stm32f4的按键消抖程序：包括配置系统时钟，按键端口初始化，设置中断模式，配置KEY连接的IO口及其中断，配置中断触发条件并使能。-Based on stm32f4 keys away shaking procedures, including configuration system clock, KEY port initialization, interrupt mode, the configuration is the KEY link of I/o port and inte