#define dataPin 2
#define outPin 6
void setup()
{
  DDRD |= (1<<outPin);        //set the pin (6) to be an output... when pin 6 is an output PORTD controlls whether it's high or low with 1 or 0
  DDRD &= ~(1<<dataPin);      //Set controllerDataPin (pin 4) to be an input
  PORTD |= (1<<dataPin);      //Set controllerDataPin (pin 4) to have a pullup resistor enabled
  attachInterrupt(digitalPinToInterrupt(dataPin), falling_edge, FALLING); //attach interrupt function
}

void loop()
{
//empty
}

void falling_edge()
{
  delayMicroseconds(2); //delay 2 microseconds
  PIND&(1<<dataPin)? //if you read a high on Pin 4
  PORTD|=(1<<outPin): //set pin 6 high
  PORTD&=~(1<<outPin);  //otherwise set pin 6 low
}