呼吸灯

void setup() {
// put your setup code here, to run once:
pinMode(3,OUTPUT);
}

void loop() {
// put your main code here, to run repeatedly:
while(1){
for(int a = 0;a<=255;a++){
analogWrite(3,a);
delay(5);

};
for(int a = 255;a>=0;a--){
  analogWrite(3,a);
  delay(5);
};

}

}