Author Topic: Infrared interference issue with the wiiboard  (Read 5773 times)

Offline Unclefro

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on: June 01, 2010, 07:14:30 AM
I am creating an interactive Wii Whiteboard to be used in my school and have run into an issue. The program runs successfully however the school has purchased an infrared voice enhancement system. The device is worn around the neck of the speaker and emits an infrared signal when the user is speaking which is recognized by the wii mote. This is obviously a problem, and while I have not been able to determine the frequency of the microphone, I would like to modify the program or the wiimote to be able to distinguish between the two sources and ignore the input from such a device. Has anyone done this successfully or know how to do it?



Offline zainey

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Reply #1 on: June 01, 2010, 09:20:25 AM
Hi,


This is an untested idea.

Use a circular polarizer on the IR microphone and the wiimote.

You need to set them up so they are 'crossed', as this blocks the IR light transmission from the IR transmitter to the wiimote, but leaves the respective IR pen channel and IR microphone channels unblocked.

For the circular polarizer, I would try getting one of those disposable clear 3D glasses from the cinema. The left and right sides are oppositely polarized, or 'crossed' as previously described.

The polarization effect may still work in the near infra-red region of the leds used.

Good luck.



Offline Unclefro

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Reply #2 on: June 01, 2010, 12:10:45 PM
Thank you very much.

I plan to look into these circular polarizers more and will post how it goes.




Offline unclefroassociate

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Reply #3 on: June 08, 2010, 07:55:15 AM
Whily my friend is currently unavailable, your advice on using the IR polarizers proved successful. By rotating filters from 3D glasses we were able to reduce the interference.

It does truly work, and thank you for your advice.



Offline zainey

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Reply #4 on: June 09, 2010, 03:18:52 AM
Hi,


I have tried the "crossed" circularly polarized 3d cinema glasses from Real3d and they do not work with my 940nm IR LEDs.

Likewise, normal plane polarized glasses don't seem to work for me either.

I was viewing the IR LEDS through my digital camera.

Maybe proper IR polarizers are required .....


If you have some better information, please let us know.


Thanks



Thanks.