Path: utzoo!attcan!uunet!ogicse!milton!nelson%melodian.cs.uiuc.edu@usc.edu
From: nelson%melodian.cs.uiuc.edu@usc.edu (Taed Nelson)
Newsgroups: sci.virtual-worlds
Subject: Re: Power Glove Interface
Message-ID: <8200@milton.u.washington.edu>
Date: 25 Sep 90 17:04:34 GMT
References: <7992@milton.u.washington.edu>
Sender: hlab@milton.u.washington.edu
Organization: Picasso Group, University of Illinois at Urbana-Champaign
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Approved: hitl@hardy.u.washington.edu



Here is a brief update on what we have found out in the past few days:

        1.  The output signal is simply one bit-per-button, thus allowing
                you to press all buttons simultaneously.  The order works
                out to be A-B-Select-Start-Up-Down-Left-Right, which is
                eight bits.
        2.  It is sensitive to the pulse lengths in an annoying way.  We
                are currently using 4us for both the reset and clock
                pulses.
        3.  We have problems centering with any clock above 4 kHz, which
                seems extremely slow since the processor inside the glove
                uses a 10 MHz clock.
        4.  Someone sent us mail reminding us to turn off the rapid fire
                buttons, which helped a lot.
        5.  Our circuit is pretty straight-forward, and substituted a one-
                shot for the icky RC circuit to control the pulse lengths.
        6.  The lights on the ultra sound don't work correctly.  When 
                centered and with no finger motions, all the lights are off
                as they should be, but any action whatsoever turns ALL of
                the lights on, which is not how the manual describes it.
                There are two lines unused in the interface, and we imagine
                that one of these controls them, although it seems silly
                to require the Nitendo to control it, unless it essentially
                feeds the dataOut signal back through and there is some
                interpreting circutry in the ultrasonics.
        7.  One of the two unused lines must be for the Nitendo to send
                stuff to the glove.  We say this since the gloveMaster/
                littleDigit thing mentions that a few games actually
                program the glove when the NES is powered up.

Does anyone have any information on anything else?  We especially want
  to get the lights working correctly and try to crank up the clock speed.

For anyone else building an iterface, we suggest making it as general
  as possible since there's a lot of weird timing going on.  We have a
  series of counters for use as clock dividers and the one-shot thing made
  the controlling of the clock pulses simpler.  (BTW, for the one-shot we
  used R=5.7k and C=1000pf.)

-- Taed and Bri