Author Topic: IR light from a distance  (Read 6589 times)

Offline jerberjer

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on: May 16, 2008, 07:52:06 PM
Hello. Recently heard about the whiteboard and had a thought: Could this system be used by projecting IR beams froma distance? Has anyone tried the green laser pointer mentioned in other threads? if so, what kind of supplies would be needed? I'd love to see if it would be possible to make an inexpensive lightgun for games in the future.

 Lurking around seems to say that the wiimote isn't very sensitive, so it seems unlikely, but I figured I'd ask because other people might have the supplies to test this out (I currently am sans a wiimote, so I can't do much at the moment)

thanks!



Offline UndCon

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Reply #1 on: May 17, 2008, 02:27:24 AM
welcome!

you have to modify the wiimote to se lasers, default it can only see IR.

IR from distance...well the IRleds arent super strong - so it is hard to tell what distance they will work at.

And dont forget about connectivity... the wiimote is connected over bluetooth - don't expect anything above 10 meters in best case (untested but i dont think they have 100m BT in the wiimote)



Offline chrisf77

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Reply #2 on: May 17, 2008, 01:06:31 PM
"well the IRleds arent super strong"
i wounder about that..

i have these 5mm IR leds from radioshack
Radiant power output (100ma) 16mW min
Foward voltage 1.2v
Foward current 100mA
Viewing angle to 1/2 intensity 45 degrees
Wavelength 940nm

thats all the info it says on the package i dont fully know what all means but incase was woundering what i was testing with.

anyway.. stuck 1 in my keychain flashlight and worked perfectly fine accress the room. i desided to try even farther max distance i was able to check is about 25-30 feet.. i had feeling it would work from at lest 5-10 more feet..

the only problem is i supose with the program.. the farther away u get from the camera the more you have to move the light around to go from top to bottom of the screen..

dunno if the camera can measure distance..?  if not just need to add something that can measure how far you are from the camera and make it all relative.



Offline UndCon

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Reply #3 on: May 17, 2008, 05:00:06 PM
in DesktopVR you measure the distance by triangulation of 2 sources, the IRleds of the IRbar

If you can incorporate this into your code you can calculate the distance....

Try to calibrate a smaller working area to keep your moves smaller - I have no projector atm so I cannot try anything :(



Offline pmoinot

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Reply #4 on: May 19, 2008, 03:00:53 AM
Has anyone tried whiteboard control using laserpointers motified to collimate IR laserdiodes like the ones in cd drives?



Offline inio

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Reply #5 on: May 19, 2008, 11:26:56 AM
Another option is to take a decent- to high-power 940nm LED and put colimating optics in front of it.  The Wii Remote can handle a fairly large spot, as long as it's bright enough, so the optics don't have to be perfect by any means.  Make sure to go with a 940-950nm LED though since the Wii Remote is WAY more sensitive to that wavelength (see the wiki).



Offline UndCon

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Reply #6 on: May 19, 2008, 01:50:52 PM
Here is a simple test



Let me introduce: Red Laser meet IR - IR, Red Laser...


Oh - the fancy IR shows us what he can do...


Red Laser - You look very out of focus dear IR...



Red Laser - Here, borrow my collimator and see what it can do...
IR - Sure Red Laser - that will improve my beam a bit ;)
- Oh -  my arms aren't long enough...I need extensions to hold your lens..


OK - It is not dark when im shooting this - I'll try more later in the evening wo we can see the IR better - and I'll try to use a  stabilized powersource

Conclusion...mount the collimator in front of a powerful IR diode and get a nice focused pinpointIR - as I mentioned before...the lens is threaded on my laserpointer - helps adjusting the diameter of the point...

...or is it IR on viagra :D

//UndCon
« Last Edit: May 19, 2008, 01:55:33 PM by UndCon »



Offline UndCon

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Reply #7 on: May 19, 2008, 03:17:19 PM
update with 2 better shots : taped the lens to my pen...





EDIT : It is the tape that looks like a glowing tube - it is there to hold the lens in place about 7mm's in front of the IRled

EDIT 2 : If the IRled has a broad angle you might need a lens with bigger diameter so you dont cut it off to much and loose strength of led
« Last Edit: May 25, 2008, 05:17:18 PM by UndCon »



Offline jerberjer

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Reply #8 on: May 24, 2008, 08:02:14 PM
Interesting. I'm about to assemble one out of an old Laster Challenge gun. It won't be very accurate, but it might be enough for just regular point and click and not so much drawing.