Wiimote Project

General Category => General Discussion => Topic started by: Ulfilas on November 07, 2009, 07:42:18 AM

Title: Multiple Pens ? Or Is only one possible?
Post by: Ulfilas on November 07, 2009, 07:42:18 AM
I wonder whether it's possible to use multiple pens at once. I've seen a system that allows 5 users at once for a digital graffiti wall - of course it might not use a wiimote - could be something else?
Title: Re: Multiple Pens ? Or Is only one possible?
Post by: boonjin on November 07, 2009, 07:41:13 PM
I wonder whether it's possible to use multiple pens at once. I've seen a system that allows 5 users at once for a digital graffiti wall - of course it might not use a wiimote - could be something else?

Hi,

As the Wiimote's PixArt optical sensor captures the light it receives and the built-in processor, also using PixArt's Multiple Object Tracking outputs the up to the first 4 coordinates of the light detected. The Wiimote has a band-pass filter which allows the IR wavelength range to pass through.

Therefore, the limitation is up to 4 IR points and you may not be able to differentiate these 4 different points without further processing. The Wiimote outputs the first 4 IR dots it detected and thus the fifth IR dot will be ignored. However, when the first IR dot is lost, the fifth IR dot will be detected. Therefore, you can utilize this property to detect more points by switching each IR source on and off at high frequencies.

Like before, you will still not able to differentiate the IR points without implementing other methods.

For a graffiti wall, you can have multiple users using the same colour spray simultaneously so that you do not need to differentiate the different points.

Regards,
Boon Jin
Title: Re: Multiple Pens ? Or Is only one possible?
Post by: mystre on December 21, 2009, 05:10:41 AM
Since infrared falls on a spectrum of different wavelenghts and frequencies would it be possible (providing the LEDs exists) to differentiate multiple lights sources that way?
Title: Re: Multiple Pens ? Or Is only one possible?
Post by: boonjin on December 21, 2009, 06:23:40 AM
If the sensor is able to differentiate the wavelengths, it may be possible to utilize different wavelengths for different IR pens. However, for the Wii Remote's output, it only gives the coordinates of the detected dots and the size. It does not provide any color/frequency information for these dots.