add listener

 // monitor for Pin State changes
 // if state is high, ON Led
        pir.addListener(new GpioPinListenerDigital(){
            @Override
            public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event){
                System.out.println(event.getState());
                
                // turn led ON if pin attached to PIR sensor is high
                if(event.getState().isHigh() ){
                    ledPin.high();
                }else{
                    ledPin.low();
                }
                
            }
        });