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FreeTrack Forum > FreeTrack : English Forum > Support : Tracking System > which one is better? the cap or the clip?

RSS >  which one is better? the cap or the clip?
zundap #1 21/01/2008 - 17h26

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hi all, i just bought a new logitec quickcam express with the vendor id of 092F ( wich i think it is fully compatible :)

now i will buy the leds, but i cannot find them near me ... my local shop only has 2 kinds:

"cqy99" and the "ld271"

here is what i could find in google

CQY99     λp= 950[nm]     IF=150[mA]      Angle±50[°]     transparent blue
LD271      λp= 950[nm]     IF=130[mA]      Angle±25[°]     transparent blue

some say that the CQY99 has a 30º angle other say 50º ...

what forward current should i use ? 1.4 ( optimal ) or 1.7 maximum?
and current? 100mA ( optimal ) or 150mA maximum?

is it possible to make a 3 point tracking system with these IR leds?

im thinking about buying a chinese power supply ( 6v 500mA ) to connect them.

basically im asking if this will work:

> logitec quickcam express ( 092F )
> 3x IR led "cqy99" or "ld271"
> 1x 35ohms resistor ----> for 3 leds @ 1.4v 100mA ( 6v )
> 1x power adapter 6v 500mA ( chinese )


i will mod the camera to remove the IR filter and apply the disk filter.

thank you for all your help!
Edited by zundap on 23/01/2008 at 23h24.
tristan68 #2 22/01/2008 - 09h47

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Hello Zundap.

1)


logitec quickcam express ( 092F )
3x IR led "cqy99" or "ld271"
1x 35ohms resistor ----> for 3 leds @ 1.4v 100mA ( 6v )
1x power adapter 6v 500mA ( chinese )



Your values are Ok , according to the provided parameters.

Maybe you'll have to sand your leds, to increase angle. You'll have to try and see.


2) hints :


If using an IR modded webcam , you usually don't need to use your leds at full power.

50 mA should be more than enough to get a correct result (I personnally use only about 20mA to 25mA in my setups, with IR modded webcam).


If you want to stick to your 100mA value, make sure to get a resistor which can handle the dissipated power (0.36W, so you'll have to get a 1W , since a 0.5W will still get hot when in use).

cya
zundap #3 22/01/2008 - 15h21

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thank you very much for your reply !

i checked at farnell to see if they sell to me and i could manage to order the recomended SFH485-P leds :D

this friday i should have them to mount the 3 dot cap.

here is what im also buying:


logitec quickcam express ( 092F ) ------------------------- 30fps as stated
3x IR led - SFH485-P
1x 47ohms resistor ----> for 3 leds @ 1.5v 70mA ( 6v )
1x power adapter 6v 500mA ( chinese )


my only doubts now are:

i have a wiimote at home and i heard that this wonderful piece of software will probably support it so here are my options:

1- mod the camera and put the leds at 20-25mA

2- give back the camera ( still have 15 days ) and wait for the wiimote support.

3-do not mod the camera and put the leds at 70mA with a photo film filter

what would you do if you were in my place ? :)

thank you very much for your support!
tristan68 #4 22/01/2008 - 17h08

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mmmmhhhh

I would personally :

- keep the webcam unmodded, and run the leds at 70mA
- use this setup until FT supports the wiimote.

- once FT supports the wiimote :

if wiimote works better AND you have a spare wiimote AND a spare BT dongle, then switch to wiimote.
Otherwise, stick to standard webcam if ok , or IR mod the webcam at this time.

cya
zundap #5 22/01/2008 - 18h06

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well, since im not modding the camera ( waiting for wiimote ) ill use a logitech sphere that actually works better than the quickcam express, and i already own one.

And I'm changing my configuration to this:


1x Quick Cam Orbit / Sphere MP ( PID 08C2)
3x IR led - SFH485-P
1x 7.5 ohms resistor ----> for 3 leds @ 1.5v 70mA ( 5v )
1x cable USB
1x 0.2A Quick release fuse
1x camera film filter

and 1 x 20ohm resistor ( to put the leds @ 25mA to use with the wiimote when it is suported )

guess there is no need to mod the camera when using the SFH485-P @ 70mA and the camera filters right?

Is this setup safe? will it work? :D btw: wich one is better?

3 points clip or the 3 points cap?
Edited by zundap on 22/01/2008 at 20h08.
tristan68 #6 23/01/2008 - 10h05

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Hello zundap


1x 7.5 ohms resistor ----> for 3 leds @ 1.5v 70mA ( 5v )




This resistor value is ok if you plan to power your leds using a 5v power source.

5V ??? do you finally get a 5v power adapter, or do you plan to use USB power ?

If you use usb power, be careful not to fry your PC's motherboard.


1 x 20ohm resistor ( to put the leds @ 25mA to use with the wiimote when it is suported )



Correct  :)



guess there is no need to mod the camera when using the SFH485-P @ 70mA and the camera filters right?



you shouldn't have to, but as usual, you'll have to try it out , since it depends of your webcam and room lighting conditions.



btw: wich one is better?
3 points clip or the 3 points cap?



Better ? Dunno, sorry.

Kestrel has the answer to such questions, i'm sure he'll drop a line here very soon  :)

cya
zundap #7 23/01/2008 - 10h41

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thank you very much for your reply tristan68!

i decided to use the USB to power the leds, and i'll be using a "0.2A Quick release fuse" so i dont fry my motherboard ( hope it protects it ).

now ill have to find out which is better , the clip or the cap :)
Edited by zundap on 23/01/2008 at 23h25.

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