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From: jmunkki@hila.hut.fi (Juri Munkki)
Newsgroups: sci.virtual-worlds
Subject: Re: PowerGlove ultrsonic sensors for reading goggle orientation?
Message-ID: <1990Sep19.211702.20234@santra.uucp>
Date: 19 Sep 90 21:17:02 GMT
References: <7806@milton.u.washington.edu>
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In article <7806@milton.u.washington.edu> ron@vicorp.com (Ron Peterson) writes:
>It just occured to me that perhaps the ultrasonics from a
>PowerGlove could be removed and used to read the position and
>orientation of a set of lcd tv or shutter goggles.  Any thoughts
>on how to prevent interaction with the ultrasonics of a PowerGlove worn
>on the hand if both were used at the same time? (Would probably help
>if they were set up orthogonal to each other to minimize crosstalk.
>Perhaps at slightly different elevations also.)  Anyone have any
>experience with crosstalk in multidimensional short range ultrasonic range 
>sensing in small spaces?

It shouldn't be a problem to have to ultrasonic sensors. In fact, you only
need one set of transmitters or receivers.

I haven't received my PowerGlove yet, so I don't know if the glove has a
receiver or transmitter, but since a receiver is probably more expensive
than an ultrasonic transmitter, they might have put a receiver in the glove
and transmitters in the frame. All you have to do to get your headset
position is to use the same transmitters and read the position.

If they put a transmitter on the glove and receivers in the frame, you
could alternate between the two devices. It will take you twice as much
time to read the position, but at least it isn't impossible. As long as
the PowerGlove hardware and firmware are secrets, it might be a problem
to work around some of their code.

Does anyone know if the powerglove only has a position sensor or does
it somehow know the orientation of the glove? Are they using three
sensors to detect orientation? A HMD needs orientation even more
badly than location.

There used to be a low-cost device for that Macintosh that could be
used as a replacement of the mouse. They decided that they had the
wrong marketing approach and now the price is so high that only users
that absolutely need the device will get it (mostly handicapped users).

Would anyone want to help me to build a device that connects the sega
3D glasses and the powerglove (or the computer version of that when
it comes out) to a Macintosh ADB bus? My serial ports are always in
use and I'd like to put these devices on the ADB bus where they belong.
I need some help deciding what processor to use (needs two serial ports
and a few I/O lines), but with some help from my friends, I'll probably
be able to design the rest.

   ____________________________________________________________________________
  / Juri Munkki     /  Helsinki University of Technology   /  Wind  / Project /
 / jmunkki@hut.fi  /  Computing Center Macintosh Support  /  Surf  /  STORM  /
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