控制蜂鸣器响，配置gpio管脚，达到按键控制蜂鸣器(Control buzzer sound, configure the GPIO pin, to achieve the button control buzzer)

KEIL开发STM系列芯片，建立工程繁琐，此版为裸机工程模板，打开之后直接撸代码即可(The development of KEIL STM series chip, the establishment of engineering complex, this project template for the bare metal, after opening the direct line of code)