This disc could have it's point of gravity off center an since the disc
would never be exactly horizontal it would give a excellent reference

Peter van Hoof
-------------
mailto:pvh@vertonet.com
http://go.to/pvh

> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Peter van Hoof
> Sent: Wednesday, September 08, 1999 8:15 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: Re[2]: [OT] Spinning LED Display
>
>
> A low cost solution to this could be a free (as free as possible) spinning
> second disc that generates an index pulse, rotation of the displayed text
> would be acceptable
>
> Peter van Hoof
> -------------
> mailto:pvh@vertonet.com
> http://go.to/pvh
>
> > -----Original Message-----
> > From: pic microcontroller discussion list
> > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Harold M Hallikainen
> > Sent: Wednesday, September 08, 1999 7:07 PM
> > To: PICLIST@MITVMA.MIT.EDU
> > Subject: Re: Re[2]: [OT] Spinning LED Display
> >
> >
> > On Wed, 8 Sep 1999 15:32:00 -0700 Scott Fink <scott.fink@MICROCHIP.COM>
> > writes:
> > >--=_sb1999/09/08-22-43-36-016=_sb
> > >Content-Type: text/plain; charset=us-ascii
> > >
> > >     I would think it wouldn't be necessary, at a faster rotation rate
> > >the
> > >     words would just spread out more (and conversly at slower speeds
> > >would
> > >     appear "squashed")
> > >
> > >     Scott
> > >
> >
> >         It does seem, though, that it's important to start the words at
> > the same location during each turn.  Failure to do this could result in
> > something similar to a vertically rolling TV picture on a TV where
> > vertical sync is lost, or, worse, just a blur because the stuff is
> > written at a different location each time.
> >         Someone's suggestion of optically detecting relative position
> > sounds interesting.  Unless the sun is directly overhead, I'd expect
> > there would be varying light intensity along the edge of the Frizbee (by
> > the way, the Frizbee was invented here in San Luis Obispo, CA).  You
> > could look for a minimum value or a maximum value in the light intensity
> > and start displaying at that time.  The stuff could be written at a
> > constant speed, resulting in the characters being stretched if the
> > Frizbee is spinning faster, but since it appears necessary to get some
> > sort of sync anyway, it should not be difficult to time stuff
> out to give
> > constant width characters.
> >
> > Harold
> >
> >
> >
> > Harold Hallikainen
> > harold@hallikainen.com
> > Hallikainen & Friends, Inc.
> > See the FCC Rules at http://hallikainen.com/FccRules and comments filed
> > in LPFM proceeding at http://hallikainen.com/lpfm
> >
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