Author Topic: Best IR LED for this pen  (Read 5305 times)

Offline TheBlackCat

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on: February 21, 2008, 03:42:41 PM
I am planning to make an IR LED pen but I don't know which LED is best for my particular plan.  I was hoping someone here would have some recommendations.  I am in the U.S.  The primary goal is to use it on a desk, so bouncing off a surface that is no where near as reflective as a whiteboard or projector screen, but also having the Wii remote most likely at fairly close range.  My main desk is fairly smooth and reflective but working on a more matte surface like paper would also be important. 

If this is even feasible I would assume I need an LED with two properties: power and a narrow focus (but please correct me if I am wrong about anything here).  Since it will be on a desk the wiimote will probably be at fairly short range, lets say under 2m and probably more like 1m.  Having it able to work at a longer range, on projector screen, on a whiteboard, or on a computer monitor are lower priorities (in decreasing order of priority), but if a single LED won't work for all of these then working at close range on a desk alone is fine.  If that is the case knowing about the best LED for longer range on projector screens and whiteboards would be helpful.  Computer screens are less important primarily because they would require the added expense of a screen cover for safety (I don't care how safe it is, I am not touching my screen directly under any circumstances).  If this LED (or LED's if I need different type) would work for makeshift sensor bars for using the remote directly that would be helpful to know since I plan on buying several anyway (I don't expect to be completely successful with my first attempt).

I would guess focus is not as important as raw power because I can always paint the sides of the pen (or actually pencil in my case) or coat the inside with solder or something along those lines, but having the power focused would reduce losses since more of the total energy output will actually be available to be detected by the Wii remote.

Another useful, but not essential, factor is size.  A 3mm LED would be better than a 5mm, but function is more important that form.  The pencil I plan to build it out of would work better with a 3mm LED but could be modified to work fine with a 5mm if necessary.  I am also not willing to pay very much more for smaller size.

Thanks in advance for your help.
« Last Edit: February 21, 2008, 03:51:31 PM by TheBlackCat »



Offline jon

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Reply #1 on: February 23, 2008, 02:45:15 AM
I am not sure if this is "best" but today I picked up LED's from Radio Shack and they work great!  They are 1.2V, 100mA, 940nm.



Offline TheBlackCat

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Reply #2 on: February 23, 2008, 10:12:31 AM
People have been saying that the radio shack LED's are very weak, too weak for what I want to do.