GeneralBW
Posts: 2
Joined: Mon Mar 26, 2012 9:51 am

Re: 2,5" LCD screen reuse

Mon Mar 26, 2012 10:17 am

Hi to you all!

I have a broken olympus fe-210 with a working 2,5" lcd and I wish to use the screen with raspberry pi. the ribbon cable has 39 wires in it with one cut for some reason and the connector has 19pins.. so thats 38 wires to 19 pins.. could someone point in the right direction on this?

any way of using the screen on rasbperry pi?? i havent found the pinout for the screen anywhere, so i guess its a dead end /: ?

I will post an image and model number as soon as i get home!!

john_wage
Posts: 156
Joined: Thu Mar 22, 2012 6:20 am
Contact: Website

Re: 2,5" LCD screen reuse

Mon Mar 26, 2012 12:30 pm

Hi there.

Handling raw LCD-TFT modules is not something you have any realistic chance of doing as a beginner.

First off there is no interface on the RPi that will match that of your LCD. Like yours, TFT-LCD modules have FPC connectors of 30+ pins sometimes upwards to 60 and that really all depends on the manufacturer.

Each of these pins need a specific signal in order for the LCD to work, many for 8-bit RGB data signal, some for synchronization clocks of various sorts, Voltage inputs, grounds, etc.

The only way of knowing which pin is what is to find out who manufactured that LCD-TFT module, then go to their website and download a PDF datasheet for it, or request one through their customer service.

So as you can see this is definitely no "plug and play" project

Some independant companies however, do manufacture driver boards for LCD's that will accept standardized signal input like RCA, VGA, HDMI etc. and will output to a FPC port specifically the interface your LCD-TFT needs, but the disadvantage is these are usually bulky (RPi size-ish), pricey ($20+) and relatively power hungry (probably draws nearly as much as the Pi itself).

Lastly, a 2,5" screen will present some apparent limitations for you,as it is a very small screen with low res, you will get very poor usability (pretty much impossible to navigate any OS, graphical or text based).

GeneralBW
Posts: 2
Joined: Mon Mar 26, 2012 9:51 am

Re: 2,5" LCD screen reuse

Mon Mar 26, 2012 1:54 pm



P/N TD025THEB5

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ledow
Posts: 36
Joined: Thu Feb 02, 2012 12:55 pm

Re: 2,5" LCD screen reuse

Tue Mar 27, 2012 10:43 am

And when you Google that part no?

I found no (useful) datasheet at all.  All I found was that it was 320x240 display made by the Shenzhen Aideal International Co., Ltd.

Without a datasheet, you're unlikely to find out what any of those pins do unless you have a degree in electronic engineering.  And even then, it'll be quicker and cheaper just to buy any panel that *DOES* have a datasheet and of equivalent or better specification.

john_wage
Posts: 156
Joined: Thu Mar 22, 2012 6:20 am
Contact: Website

Re: 2,5" LCD screen reuse

Tue Mar 27, 2012 11:31 am

ledow said:


And when you Google that part no?

I found no (useful) datasheet at all.  All I found was that it was 320x240 display made by the Shenzhen Aideal International Co., Ltd.

Without a datasheet, you're unlikely to find out what any of those pins do unless you have a degree in electronic engineering.  And even then, it'll be quicker and cheaper just to buy any panel that *DOES* have a datasheet and of equivalent or better specification.


All electronic equipment have datasheets. Sometimes not publicly available, sometimes have to be requested through support or such.

And as you suggest it is futile to try to find out on your own, but not because it would take too long time, just because it's impossible, you cannot guess valid signal formats just from probing the module with various instruments, and trial-and-error connecting would almost certainly result in destroying the module.

Themroc
Posts: 44
Joined: Fri Jan 06, 2012 9:35 am

Re: 2,5" LCD screen reuse

Wed Mar 28, 2012 2:07 pm

GeneralBW said:


P/N TD025THEB5


The first place to look is (IMO) panelook.com. In this case, they don't have a datasheet, but they do have 'em for the 2.5" 320×240 panels named TD025THEG1, TD025THEA7 and TD025THEA3. They are almost the same, so there's a good chance the ...B5 also is.

But thats the end of the good news. The less good news is:

They need several "Capacitor for charge pump", "Capacitor for VCOM low", "Capacitor for VCOM high", "Regulation capacitor for charge pump" etc. but it doesn't state the needed values. So, you'd have to get a cap-meter to find out.

Also, it needs dotclock, hsync, vsync and 8 bit parallell data (RGB multiplexed), none of which are available on the r-pi. For this you would need an expensive and hard to get (and hard to solder) smd converter chip.

Further, some (the ...G1 and the ...A7 to be precise) appear to have an i²c interface without documentation (except that register address 0x04 can somehow be used for sleep mode). It's possible that the i²c is optional, but it's also possible that the panel won't work without a proper init sequence. You'd have to get a i²c analyzer (or a logic analyzer) to find out.

So, as john_wage wrote, this would really be no "plug and play" project.

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