2_button_debounce.ino

// C++ code
// shorter cathode goes to ground -- negative goes to ground

int switchPin=8;
int ledPin=13;
boolean lastButton=LOW;
boolean currentButton=LOW;
boolean ledOn=false;

void setup()
{
  pinMode(switchPin,INPUT);
  pinMode(ledPin,OUTPUT);
}

boolean debounce(boolean last)
{
  boolean current =digitalRead(switchPin);
  if (last !=current)
  {
  	delay(5);
    current=digitalRead(switchPin);
  }
  return current;
}

void loop()
{
  currentButton=debounce(lastButton);
  if(currentButton== HIGH && lastButton==LOW)
  {
    ledOn=!ledOn;
  }
  lastButton=currentButton;
  digitalWrite(ledPin, ledOn);
}