Re: [Lcd4linux-devel] [lcd4linux] Sharp LM40001G LCD

[Michael R. <re...@eu...>]

Hi there,

>>> Interfacing it seems a bit of troublesome, as it doesn't contain a
>>> framebuffer, so all data has to be sent continuosly.
>> So does the ledmatrix display, so you might be able to do something
>> similar to its driver. 400 x  64 is 25600 pixels which in turn is 3200
>> bytes. This does not fit into the memory of any of the small avrs,
>> so you either use a mega128 (with 4k ram) or use an external ram.
> 
> Yeah, probably some sram chip from an old '286 Mainboard, got plenty of those 
> left.
> Then probably a pic18f4550, maybe ATMega16.

Well, I'm afraid this won't work that easy... from a quick glance over
the datasheet, it looks like the display consists of row and column
controllers only, but no real lcd controller.

These row/column drivers are controlled using a serial protocol, which
is a) high frequency and b) very timing critical. Thats what a lcd
controller is for.

If you really plan to build an interface, you should really consider
using a SED1550 or similar controller.

Wolfgang, are you listening? Your opinion?

> With enough ram it would also be possible to implement two different greys.
> Keep two framebuffers, display them alternating, keep one "on screen" a little 
> longer than the other (If the display timings allow that)
Again, I'm afraid this won't work, probably because of the "slowness" of
the LCD display.


bye, Michael

-- 
Michael Reinelt <re...@eu...>
http://home.pages.at/reinelt
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