Bathroom light Arduino sketch

ArduinoBathroomLight.c

// button to activate light

/*
 * Purpose: Push button activates an LED that slow fades on and after a fixed paused, fades off.
 * Change log:
 * 20080202: initial release, calling this the first prototype.
 * Code taken from:
 * Button by DojoDave <http://www.0j0.org> - http://www.arduino.cc/en/Tutorial/Button
 * Fading LED // by BARRAGAN <http://people.interaction-ivrea.it/h.barragan> 
 */
 

// Parameters
#define STEPPER 50  // how slow to fade on and off

// #define PAUSE 300000 // five minutes
#define PAUSE   500  // how long to leave the light on 
#define DEBUG   1    // see serial messages


// Vars
int inputPin = 2;  // choose the input pin (for a pushbutton)
int switchVal = 0; // variable for reading the pin status
int switchOn = 0;  // switch is set to off
int value = 0;     // variable to keep the actual value 
int ledpin = 9;    // light connected to digital pin 9


void setup() {
  pinMode(inputPin, INPUT);  // declare pushbutton as input
  if ( DEBUG  ) 
  {
    Serial.begin(9600);
  }
}

void loop(){
  switchVal = digitalRead(inputPin);  // read input value
  if (switchVal == LOW ) {            // check if the input is LOW (pushed in)
    switchOn = 1;
    if (DEBUG)
    {
      Serial.print("Turning on switch for ");
      Serial.print(PAUSE);
      Serial.println(" milliseconds.");
    }
    
    lightOn();
    delay(PAUSE);
    
    if (DEBUG)
    {
      Serial.println("Turning off switch");
    }
    switchOn = 0;
    
    lightOff();
  }
}

// supporting functions
void lightOn()
{
  for(value = 0 ; value <= 255; value+=1) // fade in (from min to max) 
  { 
    analogWrite(ledpin, value);           // sets the value (range from 0 to 255) 
    delay(STEPPER);                       // waits for STEPPER milli seconds to see the dimming effect 
  } 
}

void lightOff()
{
  for(value = 255; value >=0; value-=1)   // fade out (from max to min) 
  { 
    analogWrite(ledpin, value); 
    delay(STEPPER); 
  }  
}