class LedClass
{
  public:
    int pin;
    void on(void);
    void off(void);
    void flash(void);
    unsigned long lastTime = 0;
    int freq = 2;
    int flashStep = 100;
    int drct = 1;
};
void LedClass::flash(void)
{
  analogWrite(pin, flashStep);
  if (millis() - lastTime > freq)
  {
    if (drct == 1)
    {
      flashStep++;
      if (flashStep >= 255)
      {
        drct = 0;
        flashStep = 255;
      }
    }
    else
    {
      flashStep--;
      if (flashStep <= 0)
      {
        drct = 1;
        flashStep = 0;
      }
    }
    lastTime = millis();
  }
}

void LedClass::on(void)
{
  digitalWrite(pin, HIGH);
}
void LedClass::off(void)
{
  digitalWrite(pin, LOW);
}

LedClass led1;
LedClass led2;
LedClass led3;
LedClass led5;
LedClass led4;

void setup()
{
  Serial.begin(9600);
  led1.pin = 3;
  led2.pin = 5;
  led2.freq =  random(1,9);//闪烁的速度，数值越大，呼吸变换越慢
  led1.freq =  random(10,200);
  led3.freq =  random(40,200);
  led3.freq =  random(40,200);
  led3.freq =  random(40,200);
  led3.pin=9;
  led4.pin=10;
  led5.pin=11;
  pinMode(led1.pin, OUTPUT);
  pinMode(led2.pin, OUTPUT);
pinMode(led3.pin, OUTPUT);
pinMode(led4.pin, OUTPUT);
pinMode(led5.pin, OUTPUT);
}

void loop()
{
  led1.flash();
  led2.flash();
  led3.flash();
  led4.flash();
  led5.flash();
}