as3 timer turn external device on and off - actionscript-3

Question

I am trying to program a Phidgets device to repeatedly turn an external light on for .5 sec and off for .5 sec.
(these times correspond to Frames 1 and 11 of a 20 frame movie clip.
I've tried to insert the on- and off- commands into the movie clip, but they don't transfer to the main stage, so now I'm just trying to program the light to go on and off from the main program
The code below turns the light on and off at the SAME TIME- which means NOTHING HAPPENS.
Does anyone know how to delay the timer so that the off command comes 500 msec AFTER the on command ?
THanks
phid.addEventListener(PhidgetEvent.ATTACH,onAttach);
//connects Phidget to software
function onAttach(evt:PhidgetEvent):void{
trace(evt);
}
var phidControl:Timer = new Timer (500);
phidControl.addEventListener(TimerEvent.TIMER, lightOn);
function lightOn (evt:TimerEvent):void {
phid.setOutputState(0, true);} //this turns the light on
enter code here
var phidOff:Timer = new Timer(500);
phidControl.addEventListener(TimerEvent.TIMER, lightOff);
function lightOff(evt:TimerEvent):void {
phid.setOutputState(0, false);//this turns light off
}

Answer 1

it looks like you're creating two Timers which both run at a 500ms interval simultaneously.
It might be easier to put one function on a 500ms timer, which will call either function intermittently, something like
var lightIsOn = false;
function lightToggle(evt:TimerEvent):void{
if(lightIsOn){
lightOff();
}else{
lightOn();
}
lightIsOn = !lightIsOn;
}
---- UPDATE ----
I'm not very familiar with Phidgets, however that shouldn't make a difference in this case. Try this:
val = true;
var phidControl:Timer = new Timer(500); //If you don't set the repeat count it goes on forever
phidControl.addEventListener(TimerEvent.TIMER, lightToggle);
function lightToggle(evt:TimerEvent):void {
val = !val;
phid.setOutputState(0,val);
}
phidControl.start(); //Make sure you start the timer.
If you only want to switch it once every .5 seconds then you don't have to worry about reading the state of the light, just tell it when to change. So from what I can tell, you don't need the inputChange function.