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graphic LCD generic questions

Esmat

New member
Hi,

I have used the character lcd 40x2 and I would like to work with graphic lcd. I surveyed many of the lcd's information but still have few generic questions that I would appreciate if anybody could clarify them for me.

In my projects I have used the microchip PIC processors and they were interfaced with the lcd with 4 data lines plus 3 control lines. Most of the graphic displays use 8 data lines. Is it hard requirement or could I use the 4 lines (and transmit the data in 2 steps)?

To initialize the 40x2 I use the following code:

/* Set 8bit interface and two line display */
OpenXLCD(EIGHT_BIT & TWO_LINE & SEG1_50_SEG51_100
& COM1_COM16);

/* Wait till LCD controller is busy */
while(BusyXLCD());

/* Turn on the display */
WriteCmdXLCD(DON & CURSOR_ON & BLINK_OFF);

from this point I can display whatever string. For graphic displays do I need a specific initialization setup for each display? will the process for displaying characters be the same?
I presume that these graphic lcd's are compatible with PIC's, is this correct? Finally do these lcd's have the proper connections to connect to prototype board? Thanks
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Most of the graphic displays use 8 data lines. Is it hard requirement or could I use the 4 lines (and transmit the data in 2 steps)?
Offhand, I don't know of any graphic displays that allow a 4-bit, 2-nibble, data method. Most offer an 8 bit parallel, and some also offer 9/16/18 bit parallel options, and some offer a serial option (like SPI - clock and data, synchronized with the chip select).
For graphic displays do I need a specific initialization setup for each display?
Yes. The init sequence will be specific to the controller chip used with the particular display.
... will the process for displaying characters be the same?
Not really. The vast majority of graphic controller chips do not have a built in text capability. A few do support text, in a crude small font. The rest will require treating text as blocks of bitmapped images that represent characters. There are font editor and text library routines available to do that kind of stuff.
I presume that these graphic lcd's are compatible with PIC's, is this correct?
Generally, yes, both hardware-wise and software-wise. You will find it easier to use a high level language, rather than assembly type coding.
Finally do these lcd's have the proper connections to connect to prototype board?
Not sure what you mean "proper connections". There are a variety of connection types, from 0.1" through hole, to very fine pitch SMD flex tails. The flex tail types would typically need a "breakout" board to either solder the "hot bar" tail to, or to solder a ZIF flex connector to, that also has 0.1" or perhaps 2mm hole pattern connections.
 

Esmat

New member
Text Option

Cosmicvoid, thank you very much for your input. I should have been more clear about proper connection. What I meant is that: if I do need a special hardware to connect the lcd to .1" prototype board. I gathered from your input that some has the .1" through hole.
If I may ask you one more question: is there a classification to the lcd that indicate that they support the font editor and the text library routines? or you dig that from the datasheet! thanks again.

Esmat
 
I gathered from your input that some has the .1" through hole.
I think that most of the older monochrome graphic displays have 0.1" thru-hole pads, though I know of some that have flex tails. Virtually all of the newer color TFT displays have "hot-bar" solder-tails or ZIF type flex tails.
If I may ask you one more question: is there a classification to the lcd that indicate that they support the font editor and the text library routines? or you dig that from the datasheet!
A font editor would be completely independent of the display, and there are probably plenty to be found online. I have created one, and it is available in the 3rd party software section of these forums.

The text library routines are high level language, and not associated with any particular display. There are graphic libraries available online that are quite good, but they are also quite expensive. I have also posted code (in "C" language) in the 3rd party section for writing text to graphic displays. The only thing you will need to customize for the particular controller chip in the display is the commands to set cursor addr, write pixels, etc. If you decide to use the C language, I can give you links to code samples.
 

Esmat

New member
I think that most of the older monochrome graphic displays have 0.1" thru-hole pads, though I know of some that have flex tails. Virtually all of the newer color TFT displays have "hot-bar" solder-tails or ZIF type flex tails.A font editor would be completely independent of the display, and there are probably plenty to be found online. I have created one, and it is available in the 3rd party software section of these forums.
These older monochrome graphic displays that have 0.1" thru-hole pads: are they still available in the market?

The only thing you will need to customize for the particular controller chip in the display is the commands to set cursor addr, write pixels, etc. If you decide to use the C language, I can give you links to code samples.
I use C language, and if I can get the links to the code samples this indeed would be of great help. I am very grateful for your help.

Esmat
 
These older monochrome graphic displays that have 0.1" thru-hole pads: are they still available in the market?
Of course they are. Looks to me like you haven't bothered to look at the main Crystalfontz home page. Look at the links at the very upper right of the forum pages.
I use C language, and if I can get the links to the code samples this indeed would be of great help.
Since the code is dependent on the controller, you would need to pick a display first.

You know, you can search the forums yourself for threads about particular displays and controllers, to help guide your choice.
 
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