呼吸燈

材料

• Arduino
• LED
• 220Ω電阻

利用PWM控制LED燈的明暗

int ledPin = 9 ;

int brightness = 0;

int fadeAmount = 5 ;

void setup() {

  // put your setup code here, to run once:

  pinMode(ledPin,OUTPUT);

}

void loop() {

  // put your main code here, to run repeatedly:

  analogWrite(ledPin,brightness) ;

  brightness = brightness + fadeAmount ;

  if(brightness>=255 || brightness<=0) {

      fadeAmount = -fadeAmount ;

    }

    delay(30);

}