FreeTrack Forum

Hello!

I've discovered FreeTrack about a week ago and I just could not believe this thing would work. So I did bit of reserch, downloaded the software and gave it a shot with a romote controler and it worked!
So I was quick to get out of the house and go shoping for parts to make my own 3 point tracking system. Now since electronics are not my strong side... are not my side at all in fact, I just went to couple of shops that hold these kind of stuff and hoped to meet someone nice enough to help me.
And I did. I toled him what I need and he gave me 3 IR LEDs and 3 resistors for my 7.5V adapter (1A).
Now my plan was to find some old sunglasses, remove the lenses and mount the LEDs on to em. And so I did the next day and to my shock everything actually worked... Kinda. Problem was I had those LEDs with "bubble" so camera would only see em from 0 angle - I rotate my head just a bit and it would loose sight.

And so happy with my first sucess I decided to get myself better IR LEDs, the ones with wide angle (I did try converting these "bubbles" ones to flat ones... didn't work quite well - it's kinda hard when you have everything mounted together to grind it)
Yesterday I even bought myself a new webcamera - MS LifeCam VX-1000, but I'm not too hapy about the idea of removing the IR filter. I hope it will work like this, because I would like to be able to use this cam for other then just FreeTrack. And now I'll go out to hunt for new LEDs but...

When it comes to calculation what kind of resistors I'll need, I'm just not too sure. As I said earlier, I'll be using 7.5V 1A adapter. And according to this, there are two forward voltages: 1.5V and 3V. Now if I put 1.5V I get as a result serial assembly and one resistor of 52.5Ohms.
If I put 3V I get parallel assembly and 3 resistors of 67.5Ohms.

So which is the right one? And one last question - whick is better: 3 point hat tracking (3 points are more appart), or smaller 3 point clip tracking (3 points are closer together)? Or is there no difference at all?

Thank you for help,
Deeon

It's a good idea to file down the dome on the LED before mounting it

For the forward voltage, use the lower one, the bigger seems to be measured in rather extreme conditions (ones the LED wouldn't survive for long).

Removing the IR filter doesn't mean you can't use the cam for anything beside FT - if you don't put the visible light filter (like a few layers of exposed photo film) inside the cam, it will still give you color image, some colors will just just have slightly changed hue. But it is more than enough for things like video chat. And if you want to use FT, you'd just attach the visible light filter on the outside of the camera, eg. by rubber band or something like this.

And the setup you use - cap or clip is  simply a matter of preference - 3 point clip is designed to work set vertically on the headphones and requires the camera to be moved slightly to the side from the center of the monitor. 3 point cap is works attached to a cap or something else attached to your head (i saw a setup using head-mounted flashlight), and requires the camera to be directly in front of you, above the center of monitor. So if you don't use headphones much, you might prefer to go for the cap setup.

Hello Deeon

I confirm :

DO NOT USE 3V FOR CALCULATIONS

3V is used when driving your led using a pulse signal, that's definitely not the case in your freetrack kit.

Trying to do it will fry your leds !!!

Use :

1.5V forward voltage

and

from 20 to 70 mA forward current, depending if your webcam is IR modded or not (an IR modded cam is much more sensitive to IR , so only 20mA in your leds is far enough. If you plan to use your webcam unmodded, try 50mA or 70mA)

as values

cya

Thanks for the replys!

After visiting all local shops, I could not find 485P or any "wide angel" IR LED, so I grabbed some "bubbled" IR LEDs and I grinded the bubble off. I'm just not sure if I should polish the new flat face or leave it bit "mat" to spread the light even better.

And so by using 1.5V I would use only one resistor and do the serial assembly? It's been a while since high school, but wouldn't serial assembly make me 1st LED in the line shine the brightest and the last one the least? Will that still work?

Oh you got to be kidding me... They soled me two IR LEDsm which work great, and one blue LED... they are all clear but still how the hell did they mess em up.

So I spent couple of hours putting together 3 point side clip and now I can throw it all away. Idiots.

But on the bright side two IR LEDs work great and with floppy disket over the cam it is not picking any light at all, just IR.

Getting bit over 20FPS with VX-1000, but I didn't tweek options at all. So in the end I'm happy...

I'm just not sure if I should polish the new flat face or leave it bit "mat" to spread the light even better.

Better leave the surface matte - as you said, this will spread the light and make LEDs visible better.

Oh you got to be kidding me... They soled me two IR LEDsm which work great, and one blue LED... they are all clear but still how the hell did they mess em up.

That's why i always buy a few more elecrtonic components than i actually need :P