开发板教程：内置示例（fade）

完成

完成

完成

int led = 9; // the PWM pin the LED is attached to

int brightness = 0; // how bright the LED is

int fadeAmount = 5; // how many points to fade the LED by



// the setup routine runs once when you press reset:

void setup() {

// declare pin 9 to be an output:

pinMode(led, OUTPUT);

}



// the loop routine runs over and over again forever:

void loop() {

// set the brightness of pin 9:

analogWrite(led, brightness);



// change the brightness for next time through the loop:

brightness = brightness + fadeAmount;



// reverse the direction of the fading at the ends of the fade:

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

fadeAmount = -fadeAmount;

}

// wait for 30 milliseconds to see the dimming effect

delay(30);

}