int LED = 13;
int BUTTON = 8;
int val = 0;//0為連通，1為被遮擋不連通
int lastValue = 0;//上一次連通情況
int num = 0;

void setup()
{
  // put your setup code here, to run once:
   pinMode(LED,OUTPUT);
   pinMode(BUTTON,INPUT);
    Serial.begin(9600);
}
void loop()
{
  // put your main code here, to run repeatedly:
    val = digitalRead(BUTTON);
    if(val == 0 && lastValue != val)//如果連通并且上一次不連通
    {
        num += 1;
        lastValue = val;
        Serial.print("當前孔數為：");
        Serial.println(num);
    }
    if(val == 1 && lastValue != val)//如果不連通并且上一次連通
    {
        lastValue = val;
    }
}