这是一个由一个按键控制继电器工作状态的演示程序，当按下按键可以使原本关闭的继电器打开，也可使原本代开的继电器关闭。继电器的输出引脚请参见原理图。使用该程序可以方便的控制一个电机（外接）的起停。-This is a working state of a button control relay demonstration program, when you press the button to close the relay to open the original, but also allows the original generation of open relays closed. Relay output pin, see diagram. Can easily use the program to control a motor (external) start and stop.