Newsgroups: comp.robotics
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!oitnews.harvard.edu!fas-news.harvard.edu!newspump.wustl.edu!news.ecn.bgu.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!news.sprintlink.net!news.indirect.com!seeker
From: seeker@indirect.com (Stan Eker)
Subject: Re: LCD Dispays?
Message-ID: <D9xKEv.19E@indirect.com>
Sender: usenet@indirect.com (Internet Direct Admin)
Organization: Internet Direct, indirect.com
Date: Sat, 10 Jun 1995 00:08:54 GMT
References: <3qniba$3ed@tabloid.amoco.com> <3qv59h$m89@tilde.csc.ti.com> <3r4440$pi9@news.manassas.ibm.com>
X-Newsreader: TIN [version 1.2 PL2]
Lines: 26

Scott A. McDermott (cosmos@lfs.loral.com) wondered:
: I've seen these n-character x n-line displays in DigiKey too (though, it seems,
: for substantially more $$ than the Jameco or TimeLine products already 
: mentioned); I was wondering though, are you limited to a given character set?
: For my application I would like to be able to get at each of the dots, but
: the description (in DigiKey at least) didn't make it clear if that was an
: option.

If it's a character-type (versus graphics) LCD, you ARE limited to the font
used in the character generator, usually part of the controller chip on the
back of the PCB.  You get the standard 5x7 alpha characters, numbers,
punctuation, and many also have Katakana, but they don't allow for graphical
programming of direct bits.  If you absolutely gotta have graphical, the
display + controller board costs roughly $100+ in the salvage market, twice
or more new (for the smaller displays).

With some creative FPGA design, you can make a controller for the graphical
types and save the $100+ cost of the controller board, but you DO need info
on how to directly program the display driver chips.  Most graphics LCDs
come as 2 parts: the LCD and drivers, and the controller board.  The
controller is the biggest part of the expense.  There was an Atmel or Actel
based FPGA design in Circuit Cellar Ink a couple of years ago or so, to give
you an idea of the complexity of the job.  The files are on their BBS.
It's hard, but far from impossible, and the worst part is the cost of the
FPGA design/programming tools.

