Hey guys. I have this 2.4" LCD that I ripped from a Dell AIO printer and want to use it in some projects, but I don't know anything about the pinouts (lack of datasheet & model numbers . . ) and I'm also having trouble figuring out what I have to do to power my backlight. Any ideas? (This piece has absolutely no model numbers on it)

.. sorry about the low quality picture

 

Take the back off and if you find a chip that says HD44780, you are in luck.
Lots of info and easy to use.
Otherwise, look at it from different angles and light shining from different angles. If you see odd patterns like a clocks AM/PM or “out of paper” then it is specialized and probably no good to you. If not, then it could be a graphics LCD and that would be great but I don’t know about them yet. Good luck.

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I've thoroughly looked at the insides of it and found absolutely no marking (no words, no designs, NO BOARDS?!?!?!). The flat cable goes into a white-plastic area that spans a width and a length of the LCD, probably to control horizontal and vertical. I guess that the best I can do now is guess and check . . . I'm also wondering, for the 2" backlight, what should I do? Would an inverter for a larger tube kill it?

Also, the LCD is one of those color LCDs that the printers use so you can config and such.

 

The whte and pink wires are for the backlight, they're high voltage cables and are probably made of silicon rubber. The backlight needs an AC voltage between 500V and 1kV, 20kHz and 200kHz but the current needs to be limited to between something like 1mA and 10mA. You could try a different inverter for a larger tube but you risk damaging the inverter or the tube if you're not careful. I would experiment with adjusting the brightness setting on the inverter (if possible), the supply voltage (if that makes any difference, some inverters regulate the current) or using a different ballast capacitor but it must be rated to at least 1kV.

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I would seriously suggest you try with a standard display, and not some obscure thing out of a printer! - you wil have to reverse engineer it, and you really need the rest of the printer connected to do that! (and it's going to take a LONG! time).

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I know its not the best way to do things, but I need an LCD about that size and I wouldn't know where else to get one. Most LCDs I've seen online are alot bigger.

 

get access to the printer service manual and you will some info of who made the display and what part number- then you can write to them and get the datasheet. if the Micro you are using supports that , you could go ahead-- otherwise think of alternative- Nigel has tried to help you bypass all this hassle. Incidenatlly, you may try the LCD panels used by cellphones like Nokia3310- I saw some people writing software for it on Atmel and PIC based chips. this may be size compatible but you don't have the housing for it.

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Regards,
Sarma.

 

Oops, I wasn't too specific before, but I need a TFT LCD. (And thats what I couldn't easily find online)
Sorry if I'm being difficult, this is my first time trying to get an LCD like this to work.

 

hi,,,,,,,,,,,,,,,,,

 

What's the model of the printer?

 

It is a COLOR TFT LCD
I fear whether PIC can support it

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Regards,
Sarma.

 

Color TFT doesn't say a whole lot since its just one of the LCD technologies. Knowing the printer model might not help much either but there might be some info concerning it elsewhere on the net (like a repair guide that mentions a particular LCD number).

 

Perhaps the service manual , one we know the printer number, speaks about the code and maker of the LCD panel used.

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Regards,
Sarma.

 

Hi, The white and pink wires would normally connect to an invertor pcb, probably tucked away inside the printer, (not normally part of the display), This would normally take 5V (or thereabouts) and convert this to the high voltage for the backlight, assuming it is a cold Cathode tube.
If you cant see any chips at all, then the driver electronics will be elsewhere in the printer, probably on the main pcb, and it will be difficult to interface to the display.
'Stand-alone' displays have their own controllers on board and generally have a defined command interface protocol.

cheers
PaulB

 

Alas, usually I would jump in here with my cape and mask with a copy of the pinout...but those mini tft's are made by many manufacturers, most of which do not sell to consumers. I have a few taken from dead camera's and they have so many pins its shocking. Mainly because it has no on-board controller, just drivers for the tft. This means...chaching! usually 8-bits per colour (=24 lines) plus various clocking lines. The ones I have, have 48 connections on 0.8" wide ribbon cable, maybe 12-bits per colour.

Your best bet would be to get hold of the printer you nabbed it from. Sit down with a multimeter and do it the hard way.....tracing PCB tracks to common area's, power, ground, IC's.... then google the IC's for their pinout.
Or...if there is any writing on it what so ever you may get the manufacturer, give them a ring, quote the printer model number and demand information!
Of course the 'debugging' approach is a hell of a lot easier if you know a lot about displays and what drives them.

If you want a TFT, small or otherwise, I would check out sparkfun.com They've recentl got some new tft's (with drivers+ info). failing that? the infamous Nokia colour LCD, which is infact TFT (there are some passive CSTN's about though). These have built in drivers and are available from ebay or sparkfun.

The LCD fanatic,

Blueteeth

ps. a microcontroller CAN drive tft's for images (if you don't mind it slow looading)....but if you want video...you'll need something a hell of alot beefier.

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