// 注释  C/C++
// 函数
void setup() {  // sadsadasdsada
  // put your setup code here, to run once:
  // 设置 2 号接口/引脚 为输出模式
  pinMode(2,OUTPUT);
  pinMode(3,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  // 2 号引脚 输出高电平 -> led 亮
  digitalWrite(2,HIGH);
  digitalWrite(3,HIGH);
  delay(1000);      // 延迟/等待 1s = 1000ms

  digitalWrite(2,LOW);
  digitalWrite(3,LOW);
  delay(1000);
}