Interest in cellphone LCDs

[Alex_rcpilot]

Hi guys,I had never seen a separate LCD for cellphones until yesterday.It was a semi-transparent piece of colored panel without backlight.I didn't see any driver chips but there were only a few interfacing wires.It was really cheap.After I got back I asked some of my friends.They said the drivers have been embeded into the layer between two glass pieces,someone saw it under a microscope.I think such cheap devices will be of great value to me,if I can find the interface protocol.I really want to play with a colored LCD.Now the question is,are such protocols classified commercial information?They say such LCDs are authorized to be sold mostly for cellphone repair,but the cellphone companies never claimed that it would be illegal to develope such products.I'm worried if I try to work out the interfacing protocol,I might break the law to some extent.Can anyone tell me whether I will or not? :? By the way,if it's totally legal,where can I find the protocol information?

 

[Oznog]

Understand there are 3 levels of driving a display:
1. Glass: Must give complicated electrical levels and timing.
2. Glass drivers: You must scan in lines with std logic level, constantly. The driver does not have memory and does not store display data. Microcontrollers have a very hard time dealing with this duty directly.
3. Controller level: you give commands to modify the display data. This is the level almost all microcontrollers will need to deal with.

The LCD drivers probably are only level 2 there. With a controller chip like a SEDxxxx, you can control it just fine, but it's hard to wire all this up and you need to know a heck of a lot about the display and the controller chip.

 

[Alex_rcpilot]

The LCD drivers probably are only level 2 there. With a controller chip like a SEDxxxx, you can control it just fine, but it's hard to wire all this up and you need to know a heck of a lot about the display and the controller chip.

That's exactly what I meant by "interface" .I have no idea if the driver chips would be an SEDxxxx or STxxxx,but it's good news that you've confirmed that the embeded chips are at level 2.At the least I'll not have to build a second level driver on the base of a level 1 glass.As long as I work out the interface protocol,I will be able to drive it with an MCU or DSP.I found some useful information on how to use an ATmega8 to drive a Nokia 7250LCD,I thought of sharing the document with you guys here but it is in Chinese.I think most of the people here don't understand Chinese,so I gave up.