MWC红色Arduino板(之后的简称Arduino板)上有四个LED灯，分别为LED1~LED4。经过测试，发现其对应的引脚地址为：13,30,31,32.

需要注意：LED1为高电平灯亮，LED2~LED4为低电平灯亮。

pinMode 设置引脚的输入，输出模式；

digitalWrite向指定的数字引脚写入值；

delay延迟，参数的单位为毫秒。

int LED1 = 13; // HIGH level signal trigger
int LED2 = 30; // LOW level signal trigger
int LED3 = 31; // LOW level signal trigger
int LED4 = 32; // LOW level signal trigger
void setup() {
  // put your setup code here, to run once:
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  
}

void loop() {
  // put your main code here, to run repeatedly: 
  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  
  delay(500);
  digitalWrite(LED1, LOW);
  digitalWrite(LED2, HIGH);
  digitalWrite(LED3, HIGH);
  digitalWrite(LED4, HIGH);
  delay(500);
}