On Aug 21, 4:18 pm, Tim Wescott <t...@seemywebsite.com> wrote:
> On Tue, 21 Aug 2007 08:54:15 -0700, linnix wrote:
> > On Aug 21, 7:15 am, Tim Wescott <t...@seemywebsite.com> wrote:
> >> On Tue, 21 Aug 2007 03:58:34 -0700, Ajab wrote:
> >> > Can anyone give me any application notes/links which will help me to
> >> > understand the uC and LCD (or uC and LCD controller) interfacing ?
>
> >> Have you done web searches?
>
> >> An LCD segment turns dark (or light) when you apply voltage, and will get
> >> stuck that way if the voltage stays on. So an LCD controller applies a
> >> square wave to the segments you want to turn on -- that's a big part of
> >> the reason you need a controller instead of just logic and some resistors.
>
> > Actually, you can do it with logics and DC/DC converters. I am
> > driving an LCD panel by toggling port pins only, but it's using up all
> > the micro processing power. So, in theory, you can build an LCD
> > controller with standard CPLD, FPGA or ASIC. For high volume, ASIC w/
> > dumb uC might be cheaper than LCD uC.
>
> There are dedicated LCD controllers out there, both big and little. I'm
> currently using a small graphics LCD panel; the only data sheet I refer to
> is the one for the driver. That ought to be even cheaper than an ASIC for
> all but the highest of volumes.
We are currently using the LCD AVR, but $4 @10K is kind of expensive.
A dumb AVR is less than $1.5. I think we can add LCD function to an
ASIC for less than $1, given that we need an ASIC anyway.
> On Aug 21, 7:15 am, Tim Wescott <t...@seemywebsite.com> wrote:
>> On Tue, 21 Aug 2007 03:58:34 -0700, Ajab wrote:
>> > Can anyone give me any application notes/links which will help me to
>> > understand the uC and LCD (or uC and LCD controller) interfacing ?
>>
>> Have you done web searches?
>>
>> An LCD segment turns dark (or light) when you apply voltage, and will get
>> stuck that way if the voltage stays on. So an LCD controller applies a
>> square wave to the segments you want to turn on -- that's a big part of
>> the reason you need a controller instead of just logic and some resistors.
>
> Actually, you can do it with logics and DC/DC converters. I am
> driving an LCD panel by toggling port pins only, but it's using up all
> the micro processing power. So, in theory, you can build an LCD
> controller with standard CPLD, FPGA or ASIC. For high volume, ASIC w/
> dumb uC might be cheaper than LCD uC.
There are dedicated LCD controllers out there, both big and little. I'm
currently using a small graphics LCD panel; the only data sheet I refer to
is the one for the driver. That ought to be even cheaper than an ASIC for
all but the highest of volumes.
--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
Reply by Don McKenzie●August 21, 20072007-08-21
Ajab wrote:
> Can anyone give me any application notes/links which will help me to
> understand the uC and LCD (or uC and LCD controller) interfacing ?
On Aug 21, 7:15 am, Tim Wescott <t...@seemywebsite.com> wrote:
> On Tue, 21 Aug 2007 03:58:34 -0700, Ajab wrote:
> > Can anyone give me any application notes/links which will help me to
> > understand the uC and LCD (or uC and LCD controller) interfacing ?
>
> Have you done web searches?
>
> An LCD segment turns dark (or light) when you apply voltage, and will get
> stuck that way if the voltage stays on. So an LCD controller applies a
> square wave to the segments you want to turn on -- that's a big part of
> the reason you need a controller instead of just logic and some resistors.
Actually, you can do it with logics and DC/DC converters. I am
driving an LCD panel by toggling port pins only, but it's using up all
the micro processing power. So, in theory, you can build an LCD
controller with standard CPLD, FPGA or ASIC. For high volume, ASIC w/
dumb uC might be cheaper than LCD uC.
Reply by svenand●August 21, 20072007-08-21
If you are thinking about a text only LCD I have done an interface to
the MicroBlaze uC.
Find out more from my blog: http://svenand.blogdrive.com/archive/62.html
(Part 31-36)
Sven
Reply by Tim Wescott●August 21, 20072007-08-21
On Tue, 21 Aug 2007 03:58:34 -0700, Ajab wrote:
> Can anyone give me any application notes/links which will help me to
> understand the uC and LCD (or uC and LCD controller) interfacing ?
Have you done web searches?
An LCD segment turns dark (or light) when you apply voltage, and will get
stuck that way if the voltage stays on. So an LCD controller applies a
square wave to the segments you want to turn on -- that's a big part of
the reason you need a controller instead of just logic and some resistors.
Generally you only connect a micro directly to an LCD if the micro has an
LCD controller built in.
An LCD controller usually has an interface that makes it look like memory.
You write the correct commands and data to it, and it does what you want.
--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
Reply by Ali●August 21, 20072007-08-21
On Aug 21, 6:58 pm, Ajab <jasusvi...@yahoo.com> wrote:
> Can anyone give me any application notes/links which will help me to
> understand the uC and LCD (or uC and LCD controller) interfacing ?
www.avrfreaks.net search Projects with LCD keyword.
ali
Reply by Ajab●August 21, 20072007-08-21
Can anyone give me any application notes/links which will help me to
understand the uC and LCD (or uC and LCD controller) interfacing ?