漸亮漸暗(Fading)

漸亮漸暗(Fading)

目的: 讓 LED 持續地逐漸變亮後再逐漸變暗。


材料清單: 
1. Arduino 模組 x1
2. 麵包板 x1
3. 線材若干
4. LED x1
5. 220R 電阻 x1


電路圖:

接線圖:

程式碼:

/*
 Fade.pde 
 使用  analogWrite()  讓插在 9 pin 上的 LED 逐漸變亮後又變暗。
 */

int led = 9;           // the pin that 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);                            
}


相關連結:

1. Arduino 官網 http://arduino.cc/en/Tutorial/Fade