A siemens C75 lcd-display on an Atmel micro-controller

Here

You can download a package with the schematics of that telephone, there is nothing in there about the internals of the display however, I hope You will get something usefull out of it.

Is there nowhere some small print on the diplay indicating a type number or so?

Wishing You good luck! Yours sincerely, Rene

P.S. I know it is not what You want but nowadays You can find relatively cheap pretty LCD's e.g. on Ebay, they usually come with documentation.

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Getting data can be very, *very* challenging. I use recycled cellphone LCDs in personal projects quite frequently, and I've found the best approach is to start by buying phones for which someone has already reverse-engineered the connections and init code, or at least knows what the display controller chip is. Even once you have this information, it is often not trivial to work out how to turn on the LCD, particularly color LCDs, because many options in the chip datasheet will say "adjust for specific application" or will be mask- programmed/strapped to special settings. I have boxes of hundreds of phones here for which I have still not been able to get the LCDs working for any useful project. However I found a surplus vendor who sold me a load of Ericsson T68 LCDs (color) and Nokia 51xx and

22x0/33x0 LCDs (mono) and these have been occupying me happily for a while.

Given the small number of pins, the interface on your display is 99% certain to be either SPI, or "half-SPI" (no MISO line) or I2C. So begin by scoping out the original PCB, which will let you work out the interface and power pins. Then - and yes it's tedious - work out exactly what the phone tells the LCD between powerup and first data appearing on the display. You can then compare against various datasheets and do some detective work based on the command bytes you see, the resolution of the display, and any other characteristics you can identify.

ARGH! They did not set their MIME types correctly, and the link is hidden behind JavaScript, so it can only be opened in a browser window. I hate that! But interesting site....

Hello Rene,

Thanks for the link. I've even found a document or the C75 (the one the display comes from), but as its hidden behind obsfucated JavaScript I currently cannot download it. It'll have to wait until I get accessto a computer that does ...

I can only partially decipher a number, and not even with certainty. It starts with a vertically-mirrored R connected to an U. Than comes UC, DLB or DL8, 4305 or 43DS, followed by cv4 in even smaller print.

I've googeled for a few combinations, but had no luck in finding anything.

Yes, that would be a lot easier. But somehow getting those to work is not as interresting as getting this one to work ... What can I say, I'm a hobbyist. :-)

Regards, Rudy Wieser

-- Origi> > Hello All,

goes :

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DLB

That's an Underwriters' Labs marking, not the part number..

In fact the schematic will not help you much, because it only tells you the p/n for the connector. However it does give you the pinout and it seems to be the modified SPI type interface.

1 - DISPLAY_RS 2 - DISPLAY_RESET 3 - DISPLAY_CS1 4 - DISPLAY_CLK 5 - DISPLAY_DAT 6 - 2.9V [appears to be Vcc for the driver] 7 - GND 8 - 1.8V_CIF [appears to be Vio supply] 9 - VBOOST 10 - LIGHT_DISP

From the schematic it appears some variants have EL backlighting. This will be a pain to get working.

You have many happy hours with your oscilloscope ahead of you.

That's a symbol indicating that the display is UL Recognized, or that the manufacturer is UL Registered, so it's possible it was submitted to UL for testing or compliance with some rating.

--Gene

Hello zws(?)

DLB

Its the only number that comes near to looking like a serial-number. The only other number was on a sticker (6301.4), which I don't think is it.

--- Oops ...

I only looked at the print itself. It appears there is another number on the side of the display : LPH9157-2 G5481502.

I've just did a quick google for that first part, and came up with (effective) 1.5 pages of results, most of them datasheet search sites and a number in Russian. In short, not directly helpfull

Thanks. Thats more than I've been able to find myself.

:-) Either that or I'll throw the thing away.

Regards, Rudy Wieser

-- Origi> starts with a vertically-mirrored R connected to an U. Than comes UC, DLB

That's an Underwriters' Labs marking, not the part number..

In fact the schematic will not help you much, because it only tells you the p/n for the connector. However it does give you the pinout and it seems to be the modified SPI type interface.

1 - DISPLAY_RS 2 - DISPLAY_RESET 3 - DISPLAY_CS1 4 - DISPLAY_CLK 5 - DISPLAY_DAT 6 - 2.9V [appears to be Vcc for the driver] 7 - GND 8 - 1.8V_CIF [appears to be Vio supply] 9 - VBOOST 10 - LIGHT_DISP

From the schematic it appears some variants have EL backlighting. This will be a pain to get working.

You have many happy hours with your oscilloscope ahead of you.

Lewin :)

on

Ah. I don't know who makes them - I guess Sharp but could easily be wrong - but very many cellphones use LCDs with part numbers beginning with LPH (google "LPH LCD display").

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The datasheet does exist, you just can't get it without maybe paying for it :)

I have not generally found it worth my while to reverse-engineer and tinker for days if I have only one of any particular device.

If you give up and could use some smaller (101x80) 256-color displays for which I can actually give you the pinout and known-good initialization code, let me know. I would donate a couple to an interesting project. They come from Ericsson T68 phones I believe.

I also have lots of the Nokia 84x48 monochrome LCDs lying about, I could part with a few of them if they would be helpful. Very easy to use, again I have some sample code you could have but there is also a lot around on the net.

Oh, and I have something like 250 Motorola CDMA phones waiting to be salvaged, they are tragically very difficult to repurpose but they do contain a module featuring one large (QVGA-ish) resolution color TFT LCD and a small monochrome LCD :) Unfortunately the display part of these phones is a metal can spot-welded together, and inside we find an enormous and complicated flexible circuit heat-bonded onto the LCDs. One look at the main LCD and I can see that it is a parallel type requiring an external controller IC - not something you could drive easily from an 8-bit micro. So I have kind of given up on those, and they are in two large boxes in my attic.