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LCD pinout

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Monkeyman87

New Member
I recently removed a lcd panel out of a 2.4 ghtz wireless phone base. It has 12 pins and displays a 8 segment number and a little clock. Is there any way to decipher the pinout of this little thing? Probably next to impossible right. thanks

Heres a picture


2369-LCD900.jpg
 

Monkeyman87

New Member
Ok here is a picture of the back but there is no chip. I figured I would have to build some type of driver probably using a PIC.

2370-lcd900bACK.jpg
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I would suggest it's a great deal of work, for very little gain, much easier to use a ready built text LCD module (or a graphic one).

A bare LCD requires AC signals, so you have to arrange for that - the chip that fed it in the original phone probably had that already implemented in it's hardware - it's a fairly common feature of some micro-controllers.
 

Monkeyman87

New Member
But it would be pretty easy to create a pulsed signal with a pic. I doubt I'll be able to get a pinout for it theres probably pretty hard to trace it back on the phones pcb. Maybe if I get the pinout for the phone's chip.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Monkeyman87 said:
But it would be pretty easy to create a pulsed signal with a pic. I doubt I'll be able to get a pinout for it theres probably pretty hard to trace it back on the phones pcb. Maybe if I get the pinout for the phone's chip.

It's not just a pulsed signal, it requires a 'proper' AC signal, you need to reverse the polarity of the connections - not just swing one side from 0V to 5V.
 

Sebi

Active Member
I agree with Nigel. With little number of pins, this is a "topology multiplex" type display, so it have only two or three backplane pins for all digits. Need staircase signal for proper driving (to avoid the DC component)
 

vaineo

New Member
I've just got back from the pub!
lol

i've been looking for a simple lcd too, i've tryed taking them out of phones like Monkeyman87 did, but it's too much work to get them working, whats a good lcd to buy?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
vaineo said:
i've been looking for a simple lcd too, i've tryed taking them out of phones like Monkeyman87 did, but it's too much work to get them working, whats a good lcd to buy?

It's FAR! easier to buy a ready built LCD text module, or a graphics one (if you need graphics) - these are relatively simple to use and require very few support components. A micro and the module, and that's pretty well it.

To use a bare LCD display you've got to either use an LCD driver chip, use a micro-controller with one built in, or make a discrete driver system. I seem to remember from years back you used to feed the LCD pins from the outputs of XOR gates, with one input fed from an AC source - to give the required AC drive.

If you're making 100,000 of the item, it's perhaps worth the saving - but for a single item, or a few hundred, it's not really worth the time or trouble.
 
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