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Project Help and Ideas » Graphical LCD

August 17, 2009
by hypa_dude
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My project requires a display with AT LEAST 20x40 characters. I've found a few reasonably priced graphical LCDS at crystalfontz, but I'm not sure how to determine if the controller will interface with the ATmega168.

For example:

CrystalFontz graphical LCD

The controller datasheet says it supports a parallel 8080-series MCU Interface(8-bit, 9-bit, 16-bit & 18-bit) and a 3-line serial interface.

Is there any reason why I couldn't get this to work? Are there any other reasonably priced suggestions?

September 17, 2009
by rusirius
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I'm about a month late from the looks of things, but was looking through the posts and came across yours so I figured I'd try to answer in case you're still interested...

Yes, you can certainly make that LCD work just fine. Either through the parallel or serial interface, though parallel will be faster, and probably easier... though it'll use more i/o pins...

HOWEVER... Keep a few things in mind...

You obviously won't be able to use the nerdkits lcd.h file to interface with this, you'll have to create your own...

Looking at the mapping and timing in the datasheet, it shouldn't be too bad at all to do... BUT... Remember that this IS a graphical display, NOT a text display... In other words, you're going to need to either create your own graphics routines (lots of math! ;) or if you're looking for actual characters, i.e. ASCII, then you'll need to create a "lookup table"...

I haven't gotten into the ATMega168 far enough to know if it's onboard EEPROM would be suitable enough for this, or if you'd be better off using an external EEPROM...

Basically you'll have all the characters (each represented by a fixed grid of pixels) programmed into the EEPROM... When you need to display a certain character you'll need to pull the info out of the EEPROM and feed it to the LCD... Actually, given the right set up you should be able to feed the EEPROM directly to the LCD and only have to interface the address lines of the EEPROM...

The point is, this display is designed to display PIXELS... Each "pixel" of a certain color (R G or B) is assigned a value based on the "brightness" of that pixel for that particular color... It's NOT as simple as just feeding a character "byte" out to the display and it displaying it... The nerdkits LCD does this because it's just that, a character display... It has it's own EEPROM that contains all the ASCII "font" data...

Bottom line... Yes, it can do it, and it'd be a lot of fun... but if you're looking to just get a project accomplished and don't want to futz around with it, you'd better look elsewhere! ;)

February 26, 2010
by Hexorg
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Hm... I'm not sure if the chip that comes with the nerdkit will work with this screen, unless it has it's own cpu.... 176x220 pixels, time it all by 3 (red, green, blue), and you get one frame size - 116.160kB which is (i think) the amount of memory the best ATmega** series micro-controller has.

April 26, 2011
by hariharan
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I came across something called 'graphics library' for atmel check this link out: http://www.8052.com/users/mkaras/

April 26, 2011
by Ralphxyz
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So where is the link to the 'graphics library'?? I do not see ATmel referenced anywhere on you url

Ralph

April 27, 2011
by hariharan
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srry!!!!! link:http://www.atmel.com/dyn/resources/prod_documents/doc8094.pdf

April 27, 2011
by Ralphxyz
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Thanks, that's better.

As it says at the bottom of the forum page:

Links - [nerdkits](http://www.nerdkits.com/) will create the word nerdkits as a link to http://www.nerdkits.com/

If you wanted to use a link instead of the URL.

Any way the link is for the Atmel DB101 (ATAVRDB101) which has an on board ATmega1281 micro.

Now if only they were available, they would be interesting to play around with.

ATmel has a habit of announcing devices but never actually manufacturing them or making only limited demo kits available.

Or this might be a old device no longer made.

It certainly would make life simple to have a LCD display with a imbedded microprocessor to actually handle the display and colors as Hexorg noted.

Ralph

April 27, 2011
by Rick_S
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Mouser has them at $100 each.

April 28, 2011
by Rick_S
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Mouser $99.00 4 in stock

Digikey $105.07 6 in stock

Avnet is out of stock and Arrow's page is bad so I'm guessing they no longer carry it. Keep in mind though, I believe... which I could be wrong... but, I believe this board is meant more as a development kit to learn how to control a display by examining and modifying it's firmware in the onboard micro. Kind like a high end butterfly. It would be pretty neat to see it turned into an I2C graphic display though.

Rick

April 28, 2011
by Hexorg
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Looking at all this, I think I want to try and build NerdKit-based key-chain digital picture frame

April 28, 2011
by Rick_S
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Keep in mind, the LCD is monochrome... Just the backlight is RGB so photo's wouldn't be too exciting :D

Rick

April 28, 2011
by Hexorg
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oh, well I was talking about something like this

April 28, 2011
by bretm
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Wow, it looks like it includes some really nice source code for using it, including SD card support and FAT (DOS file system) support.

April 28, 2011
by Rick_S
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Now that's sharp. I'll have to read up on that.

Rick

April 28, 2011
by Hexorg
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Oh, sorry that product is discontinued, and replaced by this one, and its only $30

April 28, 2011
by bretm
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It doesn't have a connector that would be suitable for bread-boarding. That's a problem with a lot of this little screens.

April 28, 2011
by SpaceGhost
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I like this one - link

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