LCDInfo.com

Hello all,

This is my first post in this forum. I am a self-proclaimed character lcd graduate; I can make my own software(parallel and pic) for them and build them in less then 15 min. After seeing coorz's orange plenar lcd, I decided I should start on the graphics lcd scene. I have a few dumb questions, and I was hoping someone could answer them for me:

->The whole controllerless thing confuses me. How can you add a controller? Why wouldn't there be one in the first place?

->Why is negative voltage needed for contrast? Why can't you just put a pot on GND?

->Where is a cheap place to get a small graphic lcd? (I want to start small and build up; not ebay)

->Is a SED133x controller an ic that you go and buy, or is it something else?

Thanks in advance to anyone who can help me.

-penjuin

Hiya Penjuin. Manufacturers usually don't put controllers on LCD's because they're not sure what's going to be driving them or they want to keep costs down. eg. If a manufacturer was putting out a 640x480x65,536 colour LCD then they don't know if a customer want's to drive it via an LCD Driver chip or by converting a VGA/Composite signal. The VGA/Composite way is similar in concept to driving an un-controlled (tm) LCD in that the screen is sent a 2 dimensional array's of pixel data which the LCD displays and will keep displayed for a certain (usually measure in ms or us) period of time. After that the whole display has to be refreshed again. Anyway, LCD's with higher-level controllers will do this for you and all you have to do is tell it what to draw or update some video RAM. The lower-level LCD's that don't have controllers you have to tell it again and again what to draw, in raw format (like 50 to 60 times a second). That's a pretty average job of explaining it but it's late here and I've had a few drinks. Sorry



Who knows? Well, some LCD's come with built in voltage inverters so that you can just supply it with +5V DC and they will do the rest. Most of them don't though which means you have to design your own Inverter/Multiplier to drive it. I think it's got to do with the way Liquid Crystals work but I'm sure someone else here can give you more details. It's a pain, I know, but you can find voltage Inverter/Multipler circuits all over the internet so it shouldn't be too much of a big deal



Try one of:
* www.CrystalFontz.com
* www.matrixorbital.com

Also, try this link: http://www.allelectronics.com/cgi-bin/c ... type=store

It is a nice little LCD that is easier to program for than most graphic LCD's. You don't have to worry about multiple controller chips and the graphics memory is laid out in a fairly intuitive manner



Well.... you CAN buy them, but it's not always easy as they are usually sold in bulk to manufacturers. There are people/company's around that will sell these devices but almost all of them are surface mount. I wrote another thread about a 240x160x512 color LCD display that can be driven without an LCD controller if you're interested:

http://forum.lcdinfo.com/viewtopic.php?t=1383

Anyway, it's a VERY interesting project (at least to me) and will teach you a lot about how to drive LCD's that have no (or atleast, very dumb) controllers)



No problems Anyway, I hope that helps a little

HumanBe**a**n (I forgot the 'a' when I signed up [/quote]

Wow, thanks! I get everything now, except the negative voltage thing, but thats ok!

Does anyone know a place in Australia I can buy a gfx lcd cheap? Getting them from the US is hard for me.

-penjuin

Some good info on LCD's and technology;
http://www.hantronix.com/3_1.html

Contact Aussie member Syridian he might have some things for sale.

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My Plexeon-Insane LCD!-Or this one!-LCDinfo-LCDStudio

OT: Coorz, you don't happen to have any spare Planars to sell?-)

You and me both. I live in Adelaide and about all you can buy here is 16x2 character LCD's from Jaycar or DSE. www.futurlec.com.au seems to be a pretty good place to buy stuff but their graphics LCD's are all expensive and lack manufacturer/controller data so you have no idea what you are buying.

Other than that, the only thing I can say is that you'll probably have to get used to buying from the States because there is stuff all over here and what little there is is waaaaaay overpriced. If I find any decent supplier over here though, I'll let you know

http://cgi.ebay.com.au/LCD-Graphics-160 ... dZViewItem

Not bad price, T6963C controller, should be an easy one. Needs DC converter though.

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My Plexeon-Insane LCD!-Or this one!-LCDinfo-LCDStudio

www.futurlec.com (the us site) has the controller info and an attempt to make a datasheet. I believe both shops sell the same lcds.

Do you have one of these humanbean? I cannot see how to order one to Australia. At the checkout section there is only USA, Canada and Mexico. Any ideas?

Penjuin, I don't have one. I tried to order it but I coulnd't figure out how to from their web site so I sent them an email. They took so long getting back to me that I ended up buying a few of those colour Sony LCD's from Electronic Goldmine instead. Here is their (late) reply:



My experience with Electronic Goldmine was much better though. It only took a week for my 3 displays to show up and I was happy with their customer service. Incidently, the postage costs from E.G. for 3 US$20 LCD's was US$33. You can probably get it cheaper, like down to US$11 or so but it will take two or three times longer to get your package, but I just didn't want to wait Oh, they also have a minimum US$50 purchase for overseas customers

BTW, I took your advice regarding Futurlec and bought one of their 128x64 graphics LCD modules. It hasn't arrived yet (it takes a week for things to arrive from Futurlec using their AU$4 postage option) but another group of stuff from them has. Other than their long delivery times (they are actually based overseas) they were quite good. Their prices for AVR's are excellent and all the other places I've found to buy them in Australia are AT LEAST twice as expensive, sometimes 3 times more!

Anyway, that's the summary of my recent online purchasing

Futurlec is great isnt it . All but one of my character lcds are from there, and i've also got some dirt cheap atmels. Let me know how the 128x64 turns out.