//功能：使LED以1HZ頻率閃爍  
#define PIN_LED 13             //宏定義13號端口為PIN_LED  
void setup() {  
  pinMode(PIN_LED,OUTPUT);     //初始化13號端口為輸出  
}  
  
void loop() {  
  digitalWrite(PIN_LED,HIGH);  //13號端口輸出高電平  
  delay(500);                  //延時(shí)500ms  
  digitalWrite(PIN_LED,LOW);   //13號端口輸出低電平  
  delay(500);                  //延時(shí)500ms  
}