// #########################################
//           Varry LED Brightness          
// #########################################
// 
//  LED Brightness Control on Arduino UNO using PWM
// 
//  Check out the link for Code explanation and Hardware details
//  Link: 
//    http://tech.arunkumarn.in/blogs/arduino-uno/led-brightness-control-on-arduino-uno-using-pwm/
// 
// Arduino UNO has 6 PWM channels (D3, D5, D6, D9, D10, D11)


#define ledPin 9         // PWM capable pin
int brightness = 0;      // current LED brightness
int fadeAmount = 3;      // how many points to fade the LED by

void setup() {
  // Set ledPin as OutPut Pin.
  pinMode(ledPin, OUTPUT);

}

void loop() {
  // Set the brightness of ledPin (GPIO 9)
  analogWrite(ledPin, brightness);
  
  // Change the brightness for the next loop
  brightness = brightness + fadeAmount;
  
  // Reverse the direction of the fading at the ends
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  
  // Wait to see the dimming effect
  delay(10);

}