int Led=13;   //定义LED 接口
int buttonpin=3;     //定义按键开关传感器接口
int val;               
void setup() {
  // put your setup code here, to run once:
pinMode(Led,OUTPUT);//定义LED 为输出接口
     pinMode(buttonpin,INPUT);//定义按键开关传感器为输入接口
}

void loop() {
  // put your main code here, to run repeatedly:
val=digitalRead(buttonpin);//将数字接口3的值读取赋给val
    if(val==HIGH)//当按键开关传感器检测有信号时，LED 闪烁
        {
         digitalWrite(Led,HIGH)
        }
   else
      {
      digitalWrite(Led,LOW)
      }

}