Arduino Led Fade

Fading


Demonstrates the use of the analogWrite() function in fading an LED off and on. AnalogWrite uses pulse width modulation (PWM), turning a digital pin on and off very quickly, to create a fading effect.


The Circuit




Connect the anode (the longer, positive leg) of your LED to digital output pin 9 on your Arduino through a 220-ohm resistor. Connect the cathode (the shorter, negative leg) directly to ground.

/*
 Fade

 This example shows how to fade an LED on pin 9
 using the analogWrite() function.

 This example code is in the public domain.

 */
int brightness = 0;    // how bright the LED is
int fadeAmount = 5;    // how many points to fade the LED by

void setup()  {
  // declare pin 9 to be an output:
  pinMode(9, OUTPUT);
}

void loop()  {
  // set the brightness of pin 9:
  analogWrite(9, 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);                          
}

These icons link to social bookmarking sites where readers can share and discover new web pages.

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

Tags: Arduino projects