• analogWrite(led, brightness); PWM 輸出，在此指定~9 有PWM輸出
• || 代表"或"(or)，只要兩者都符合或只符合一個，就為真

Arduino程式碼

const int led = 9;           // PWM pins: ~3, ~5, ~6, ~9, ~10, ~11
int brightness = 0;          // LED brightness variable
int fadeAmount = 5;          // Brightness change variable

void setup() {
  pinMode(led, OUTPUT);      // Set led pin as OUTPUT
}

void loop() {
  analogWrite(led, brightness); // PWM output

  brightness += fadeAmount;    // Adjust brightness

  // Reverse the direction of fading at the extremes
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }

  delay(30);                   // Delay to improve breathing effect
}

程式碼ino檔 github下載

實作影片