FreeTrack Forum

Welcome, you're not connected. ( Log in - Register )

RSS >  Leds help
Spacejoy #1 14/10/2011 - 22h06

Class : Apprenti
Posts : 9
Registered on : 14/10/2011

Off line

Hello everybody  :)

I read that, and see on Youtube, that it is not nessesery to use IR leds.
Some say's that you better don't use IR leds.
I know now that IR leds use about 100mA so it not usefull for battery's.
Normal leds use 20mA. That is better for the lenght of the battery's.
But in de manual I read something about 860nm.
So, I am confuse what is a good normal led.
Can somebody tell me please with sort of leds than is usefull.
Is also the collor important?
Blindasabat #2 14/10/2011 - 22h30

Class : Habitué
Posts : 83
Registered on : 02/05/2011

Off line

Hi,

It's up to you if you want to use normal leds if you want leds that are visible lit in front of your eyes, I prefer invisible light  leds. I've read that red colored leds are best, since they are closest to IR in spectrumfrequency, but I've seen people use other colors too, yellow for example.
Edited by Blindasabat on 14/10/2011 at 22h32.
Spacejoy #3 14/10/2011 - 22h56

Class : Apprenti
Posts : 9
Registered on : 14/10/2011

Off line

Hi,  :D

Invisible leds? I go look for them.
But is it then not important that the are 800nm.
I mean, Can I use also 500nm leds?

An other question I ask myself is, what is the difrence in working with 3 or 4 leds?
I don't read it anywhere.
Blindasabat #4 15/10/2011 - 13h09

Class : Habitué
Posts : 83
Registered on : 02/05/2011

Off line

Use the Osram SFH485P LED's, these emit IR light.

http://shop.strato.de/epages/15485180.sf/en_GB/?ObjectPath=/Shops/15485180/Products/%22Osram%20SFH485P%22

This is a link to a German webshop, but they are not hard to find, Radio Shack or Conrad also sell them.

As for 3 or 4 point model, go for the 3 point, it is easier to build and the 4 point model has been dropped by FreeTrack and is only supported for backward compatibility for people who still use this model. I think it was because 3 point was more accurate and easier to track. You can use battery power if you want, I advise to use a PP3 battery (9Volt battery), because these provide ample power over a long time. Take in mind that rechargeble batteries normally provide less power, 7.2Volt or so, it is still more than enough but you have to calculate a lower (less Ohms) resistor for it, otherwise your LED's may not emit bright enough.
Spacejoy #5 15/10/2011 - 16h13

Class : Apprenti
Posts : 9
Registered on : 14/10/2011

Off line

Hi,
I used now LD274. 950nm 1,3-1,5V. 100mA.
I make the head flat and pollised them so the range is bigger.
I set them parallel and not in serie.
For the power I used no Battery but an adapter 5V 410mA.
AndiIt works Great in FreeTrack  :stuart:  after that I modified the webcam.
Edited by Spacejoy on 17/10/2011 at 22h07.
opusthefowl #6 07/11/2011 - 17h21

Class : Apprenti
Posts : 5
Registered on : 28/10/2011

Off line

Spacejoy

What did you use to polish the LED? I've flattened one with better results than a non-flattened LED but I can't remove that white layer on the flat part.

Thanks!
C6_LeBorgne #7 08/11/2011 - 22h52

Class : Beta Tester
Posts : 224
Registered on : 09/08/2007

Off line

use a dremel with polish drum and polishing compound


Posted ImagePosted Image

Works fine
Posted Image
C2D 6420 , 2Go DDR II , 570 GTX , Wiimote , A-quip mini BT Dongle , Thrustmaster Warthog , Pro Gamer Command Unit et PCDASH2

 >  Fast reply

Message

 >  Stats

1 user(s) connected during the last 10 minutes (0 member(s) and 1 guest(s)).