Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!hplabs!hp-pcd!hplsla!tomb
From: tomb@hplsla.HP.COM (Tom Bruhns)
Newsgroups: sci.electronics
Subject: Re: Animatronics toys
Message-ID: <5170041@hplsla.HP.COM>
Date: 16 Jun 89 14:16:25 GMT
References: <7055@cbmvax.UUCP>
Organization: HP Lake Stevens, WA
Lines: 22

edw@wells.UUCP (Ed Wells) writes:
>
>  I heard that Teddy uses a similar coding that is used for most of the
>TV remote IR units.  I've never verified this, however, it stands to
>reason that this may be true.  The IR chips are readily available for
>pennies and won't have required a "new wheel to be invented".

Not quite, I think.  The encoding is as a 9-pulse train, repeated
continuously, with longer gaps between trains for synchronization.  The
information is encoded as the analog pulse separation between adjacent
pairs.  Each of the eight adjacent pairs is assigned a channel:  Teddy's
eyes, Teddy's mouth, Grubby's ... etc.  Teddy, at least, decodes it
with some analog IC's and a 74HC164.  Not the chips you mentioned, but
still "pennies".
>
>  Why do you ask?  Are you trying to interface with Teddy or want to
>know for another project?  If it's for another project, try to use
>the IR chips yourself.

As the original poster noted, he bought a Grubby for "pennies" w/o
a Teddy, and would like to get him walkin' and talkin'.  (You did
get my email with the details, didn't you??)