Author Topic: What IR LED's do people reckon I should use for the following . .  (Read 12848 times)

Offline mattgaunt

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Hey everyone

New here so first things first, Hi!! lol

I'm doing some work on the jonny lee head tracking demo but I'm having one very very large problem at the moment. The demo I'll be doing will be done on a projector screen and as such the user will be say 10m away from the screen, and currently the wiimote is struggling to pick up the IR LED's this is partly to do with the viewing angle of the LED's and partially to do with the intensity not being strong enough.

Does anyone have any suggestions for fixing this? I have a very vague understand of electronics but no specifics about reading the datasheets for LED's.

My current set of glasses have 9 LED's put on some curved plastic of each side of the glasses (My attempt to fix the viewing angle issue which hasn't worked.

So yeah any suggestions would be great because at the moment I'm a bit in the dark.

Many thanks

Gaunt



Offline Wiweeyum

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Well, I can imagine first things first would be to make sure you're using the Vishay TSAL 6400 LEDs. Though I've not had any experience with any other LEDs, everyone agrees that these are the best ones around as far as viewing angle. To get them at a good price without having to go bulk, check out http://penteractive.us/. I bought my pen from him, and he shipped it quickly with no hiccups. That's a great resource.

Also, I know that the wii sensor bar has multiple LEDs on each side to correct the viewing angle issue. They're each pointed at a slightly different angle so you can be at an angle and still have good intensity. It seems like you've tried using a curved plastic lens to do something similar, but maybe physically moving the LEDs to point different directions could help.

As for intensity... make sure each LED has enough power to keep them all at their brightest level. If you're using 9 on each side, I can imagine that would be plenty enough to be bright enough for the wiimote to register from over ten meters. My only other suggestion would be to just add more to either side... which would look funny. :)

Hope that helps, and keep us updated.


~"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."~
- EF Schumacher


Offline mattgaunt

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That looks like exactly what I want in terms of viewing angle, Ill probably post a schematic here if anyone here would be able to sanity check it and give me any advice to get best strength from each LED.

It's interesting to hear that the Wii sensor bar is positioned slightly differently to get around the viewing angle problem so I think ill continue down this route but and do it alot more accurate than I previously done it.

Heres an old old version of the glasses

http://i26.photobucket.com/albums/c112/mattgaunt/IMG_0714.jpg



Offline UndCon

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If you only want to buy Vishay's you can get them cheap from me.

http://www.wiimoteproject.com/other-ir-products/vishay-tsal-6400-t1506/


//UndCon



Offline Wiweeyum

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Here's a video I recorded of my sensor bar up close so you could see how the lights are situated. I didn't feel like taking it apart, so just use you imagination. :)

When the lights are brightest, it's because it is facing the camera directly. When the camera is looking down from the top, you can see that the two on the outside face out a bit more than the three in the center.
[youtube]http://www.youtube.com/watch?v=P32vMuW0xCA[/youtube]



~"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."~
- EF Schumacher


Offline mattgaunt

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Hey

Cheers for the video and advice here's a little update on what I'm doing so far.

As you've all said, the wii sensor bar has it's LED's positioned differently to get better coverage so with this in mind I've tried to make a box that'll position my LED's to give full coverage past 5m away (As the room it'll be used in is around 10m between the user and the wiimote.

So I came up with this





Now I know the actual thing looks pretty rough around the edges but I didn't spend too much time putting it together plus its made out of paper so if pretty flimsy.

So heres where I need some advice on what people think, while it could work well, there is the problem of - if I make it out of card it could still break sooo easily, but would plastic work?
Also is what I'm doing logical or do people think I've lost it and going completely off the mark? I have drawn up a CAD sketch of what the LED's should do in terms of luminance  (See below) but I'm kinda out of my depth and just doing what makes sense to me so please feel free to give me advice.

http://i26.photobucket.com/albums/c112/mattgaunt/SanityCheck-1.png

Thanks alot

Gaunt



Offline Wiweeyum

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I would attempt to make it out of plastic. I'm almost certain the paper would cover up the dots on the opposite sides of that box. Even though they're not in the optimum position, they're still emitting light, and seeing them no matter how faint would be good.

Maybe adding three leds to the center? Obviously that's not important yet, but in case your current idea doesn't work, then that's a possible next step. I'm just using the sensor bar as a reference for how many it takes to get it working.


~"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."~
- EF Schumacher


Offline mattgaunt

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Right another update - I just bought some glasses to fit the new design onto and luckily my housemate offered to make a metal frame to hold the IR LED's in place, so I knocked up a design and he's putting it together.

Ill produce a Circuit Diagram and see what you guys think of it.

Gaunt



Offline mattgaunt

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To give everyone an update

The template for the metal frames that'll hold the LED's are here -> http://i26.photobucket.com/albums/c112/mattgaunt/MetalFrameTemplate.png

I've mostly been doing some work on the circuit diagram to power the LED's although this is still constantly changing as I'm not particularly great at it.

At the moment it's standing as :


But I'm unsure as to whether this will adequately power all 10 IR LED's.

One big concern at the moment is someone suggested there could be health risks when running the IR LED's at 100mA.

Does anyone know anything of this?

Also final thing - a quick diagram of what the set-up will be.

http://i26.photobucket.com/albums/c112/mattgaunt/Diagram.png



Offline UndCon

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If you are unsure about power - use the ledcalculator

http://ledcalculator.net/