Re: [avr-chat] LCD duty cycles, help please

[Stephen Wong]

Well, even on on a graphic LCM, the MCU/LCM interface is 
still very much the same, you write some commands to the 
LCM, and the LCM will execute the commands (toggle the 1/0s 
to indicate pixels) and scan the LCD.  Of course, there are 
bare bone LCDs, especially tailor masked LCD, which require 
active MCU participation to scan all the lines.  But I don't 
think you will come across such bare bone LCD in Radio 
Shack.  See the spec sheets for sure.

The negative voltage required on some LCM can be generated 
by an IC.  But you need more data, say the pin outs, AC / DC 
spec, in order to know how to interface the LCM with an MCU.

My 2 cents.

Stephen Wong @ Hong Kong

From James Dessart:
> On Mon, 28 Feb 2005 00:00:21 +0800, Stephen Wong <address@hidden> wrote:
>
> > Very likely, you don't have to deal with the "duty cycle" of
> > your LCD.  The LCD controller will take care of the scanning
> > cycles.  
>
>
> It's a graphic LCD module with no controller, and a 4-bit parallel
> interface. I'm also a little unclear on how to generate the negative
> voltage needed to drive the CD. I imagine it's the LCD drive power
> that needs to be duty-cycled, right?
>
> Thanks,
> James