Create a "breathing" pulsing effect on an array of LEDs

led_pulse.ino

// Arduino Workshop Project 3
// PWM

int d = 5;              // d is used for time delay
const int number_of_pins = 5; // the number of output pins
int pins[number_of_pins] = {3, 5, 6, 9, 10};  // an array storing each output pin

// Sets the proper pins to output mode
void setup()
{
  for (int i = 0; i < number_of_pins; i++)
  {
    pinMode(pins[i], OUTPUT);
  }
}

void loop()
{
  // Loop through each pin in pins array, pulsing them one at a time
  for (int i = 0; i < number_of_pins; i++)
  {
    pulsePin(pins[i]);
  }

  // Pause for 200 milliseconds
  delay(200);
}


// ******* Helper methods *******

// Function: lightUpPin
// Write analog values 0 to 255 to the specified pin
// Parameter: pin - the pin to light up
void lightUpPin(int pin)
{
  for ( int a = 0 ; a < 256 ; a++ )
  {
    analogWrite(pin, a);
    delay(d);
  }
}

// Function: lightUpPin
// Write analog values 255 to 0 to the specified pin
// Parameter: pin - the pin to dim
void dimPin(int pin)
{
  for ( int a = 255 ; a >= 0 ; a-- )
  {
    analogWrite(pin, a);
    delay(d);
  }
}

// Function: pulsePin
// Pulses a pin from analog 0 to 255 and back to 0
// Parameter: pin - the pin to pulse
void pulsePin(int pin)
{
  lightUpPin(pin);
  dimPin(pin);
}