该程序实现独立按键去控制 LED灯 的亮灭，并讲叙了对按键的处理方法。 独立按键相应的IO口平时为高电平，一旦按键按下，单片机便检测到低电平。-The program implements the independent button to control the LED lights off, and spoke of the right key approach. Independent buttons corresponding IO port usually is high, once the button is pressed, the microcontroller will detect low.