JunkYard LCD's - How to use them ?!

[TiagoSilva]

Hello All .

I have some LCD i bought in a junkyard from some phones and atm machines, but i can't find any datasheet for them or at least by those references i will show you them :
--------------------------------------------------------------------------------------
16x2 Characters:
(Made in China :lol: )

(A stick in the back): (Drawn in Copper at the back):
UC242908 SamSung
GNBR3-CA 94V0 3299
990927 MCL M01

(An IC, perhaps from Mitsubishi in the back too):
A0645291
(The Brand Symbol) M38067MC
-130GP
936100
--------------------------------------------------------------------------------------
16x2 Characters
(In the front, below the LCD, drawn in copper): DM26Z-3
(In the Back, drawn in copper):
GEB-22
94V-0 S

(Three IC's in the back):
2xOKI: 1xSanyo:
M5839C LC7985NA
1802V 8732 2B2
--------------------------------------------------------------------------------------
16x2 Characters
(This one has 2 board mounted IC's (Those Black Spots in the Board :lol: ) )
(And this is Drawn in the back copper):
L2432
(The brand Symbol) 94V0

(This is Painted in the back in black ink):
7W7611901J
--------------------------------------------------------------------------------------

If you know what are the real references ou the place to get the datasheets, answer please they, they are here lost to the dust when i could give them some use .

Thank You all.

 

[Exo]

If they have a 14 or 16 pin connection strip somewhere they could be HD44780 compatible

http://home.iae.nl/users/pouweha/lcd/lcd.shtml

One way to find out... try it.

 

[TiagoSilva]

Hehehe that was fast :lol: .

I allready have been there, but i found something curious !!

Pete says that for LCD's with less than 80 Chars the conection has 14 pins, but, my LCD's all, have 16 pins, except the one from SamSung (i guess that that it is from SamSung because of the inscription in the board).
All but the SamSung have 16x2 (I count the chars with the light reflex !!!!)
they have 16 pins (so they go against the Petes Law at the site you gave)

Is any possibility of these been of some other standard that not the HD44780-based ???

 

[Nigel Goodwin]

Pete says that for LCD's with less than 80 Chars the conection has 14 pins, but, my LCD's all, have 16 pins, except the one from SamSung (i guess that that it is from SamSung because of the inscription in the board).

That doesn't make much sense, the extra two pins are just for backlighting - even if the display isn't backlit, the extra 2 connections are often there.

Generally, pretty well all text LCD modules conform to the Hitachi standard, even those which don't use Hitachi chips - it's uncommon to find ones which don't, although some very old ones are different (probably from back before it became a standard).

 

[TiagoSilva]

Hello Mr. Nigel, its an honor to have your repply.

I tought so, i followed the tracks from the last 2 pins and yes the end up in some place to mount the backlite, but i've tested one the 1st one in above, just by powering it i didn't have the time to build any program to test it better, but it doesn't even blink the screen.

Is it suposed to give any life signal after i power it ??



Well, Thanks All .
Have a nice Easter.

 

[Exo]

When powering an HD44780 LCD the upper line should have all pixels activated. Showing all 'black boxes'

 

[TiagoSilva]

Hmmm, then or the pins are disposed in other manner than in the Petes page ,i have burn anything while testing or i bought then allready burnt.

Well i just tested one, but i had this doubt and i didn't whant to run errand with the other ones.


I must take time to test the other 2.

Well, Thank you .

Have a nice Easter .

 

[Nigel Goodwin]

I tought so, i followed the tracks from the last 2 pins and yes the end up in some place to mount the backlite, but i've tested one the 1st one in above, just by powering it i didn't have the time to build any program to test it better, but it doesn't even blink the screen.

Is it suposed to give any life signal after i power it ??

I spent a lot of time writing my PIC LCD routines, and during that time I noticed that if the code didn't work, or even without the data pins connected, by adjusting the contrast control you can get a display. All you get is a single line of solid block characters - but at least it gives an indication that the display is doing something.

But you must have the contrast control connected, and turned up high, or I suppose, simply short the pins together for maximum contrast. If the contrast pin is left disconnected, you don't get anything at all.

 

[TiagoSilva]

I did that that's why i think i have the pins mistaken, as i said i will try the others too.



Thank you
Have a nice Easter (again :lol: ).

 

[Nigel Goodwin]

Have a nice Easter (again :lol: ).

Thank you, you have a nice Easter as well :lol:

I'm at work today and Saturday, but I'm off Sunday, Monday, and Tuesday :lol:

 

[TiagoSilva]

Hehehehe that's great, where do you work ? That you can be in the internet answering me ? lol


Well, its better 3 Days off than one that everyplace is closed lololololol

Well, good Easter (i sound like a old answering machine saying the same thing over and over again :lol: ). May the Easter Bunnt bring you all lots of candys lolol .

 

[Nigel Goodwin]

Hehehehe that's great, where do you work ? That you can be in the internet answering me ? lol

I work in a TV service department, I use the net a lot at work, most spare parts and service manuals are now accessed on the net - and I have ADSL at work :lol:

 

[TiagoSilva]

Such luck doesn't come to everybody lol ho well, lol,
since we are here writing about the LCD's it happens that i have a Basic Stamp 2 here at home and i'm looking for any way to use these parallel devices with the Basic Stamp 2, but i don't know (yet) you to simulate one 8 Bits port with it if you know how i'm all ears (in this case eyes) lollololol.


And the same i wrotted before, :lol: (Nice Easter) lololol

 

[Nigel Goodwin]

Such luck doesn't come to everybody lol ho well, lol,
since we are here writing about the LCD's it happens that i have a Basic Stamp 2 here at home and i'm looking for any way to use these parallel devices with the Basic Stamp 2, but i don't know (yet) you to simulate one 8 Bits port with it if you know how i'm all ears (in this case eyes) lollololol.

A quick google search found this https://www.weethet.nl/english/basicstamp2_lcdcontrol.php

 

[TiagoSilva]

Thanks

 

[ele_ssar]

Hi,
I have the same LCD (UC242908 SamSung) and I've found this infos.

On the back there is M38067 mcu and the 16 pins connector of the board is wired like this :

16 - pin 74 mcu (P67/AN7)
15 - pin 30 mcu (Vss)
14 - pin 75 mcu (P66/AN6)
13 - connected to R7 on the board
12 - pin 76 mcu (P65/AN5)
11 - pin 71 mcu (Vcc)
10 - pin 77 mcu (P64/AN4)
9 - connected to R3 on the board
8 - pin 78 mcu (P63/AN3)
7 - pin 26 mcu (P41)
6 - pin 79 mcu (P62/AN2)
5 - pin 27 mcu (P40)
4 - pin 80 mcu (P61/AN1)
3 - pin 23 mcu (P42/INT0)
2 - pin 1 mcu (P60/AN0)
1 - pin 22 mcu (P43/INT1)

I think that data bus is :
2 - 4 - 6 - 8 - 10 - 12 - 14 - 16
D0 D1 D2 D3 D4 D5 D6 D7

MCU power :
11 = +5v
15 = gnd

But for 7, 5, 3, 1 I don't understand fonctionnality and

pins 13 and 9 are connected like this (I think that is LCD power but I dont know how to connect) :

                        ____R________________________________________
                       |             |                               |
                       |             |                               |
13 -------R--------------------------T                               R
                                     |                               |
                                     |                               |
                             --------T                               |
                             |       |___ pin 10 mcu(P57/DA2)        |
                             |                                       |
                             +---------------------------------------|
                             | 
9 --------R----------------- T 
                             |
                             GND

Where R = resistor and T = transistor (npn, pnp ???)

how to conect this pin ???

Thanks in advance

 

[Roboticinfo]

reply

This post has not been in use since April 2004 so why are you posting it now?

Also he said that he got it already so this topic is over.

Newbies :roll:

 

[ele_ssar]

Ok, I post new topic

 

[martin40]

Need your help!

I am sorry I'm not good at English first.
I have a LCD,but I don't know how use it.The basic information in below:

-------------------------------------------------------------------------------------
16x2 Characters
(In the front, below the LCD, drawn in copper): DM26Z-3
(In the Back, drawn in copper):
GEB-22
94V-0 S

(Three IC's in the back):
2xOKI: 1xSanyo:
M5839C LC7985NA
1802V 8732 2B2
-------------------------------------------------------------------------------------

If you have any data,please relate me.My Email is m_artin40(at)yahoo.com.cn.
Thanks Verrrrrrrrrrrry Much For Your Help!!!

 

[Nigel Goodwin]

Re: Need your help!

I am sorry I'm not good at English first.
I have a LCD,but I don't know how use it.The basic information in below:

-------------------------------------------------------------------------------------
16x2 Characters
(In the front, below the LCD, drawn in copper): DM26Z-3
(In the Back, drawn in copper):
GEB-22
94V-0 S

(Three IC's in the back):
2xOKI: 1xSanyo:
M5839C LC7985NA
1802V 8732 2B2
-------------------------------------------------------------------------------------

If you have any data,please relate me.My Email is m_artin40(at)yahoo.com.cn.
Thanks Verrrrrrrrrrrry Much For Your Help!!!

If it's got 14 or 16 pins (in either a single or double row), it's almost certainly an Hitachi compatible unit, it's very rare to find one which isn't.

There is LOT'S of information about them on the net, you can usually ignore any numbers on the back of the actual display. My PIC tutorials give plenty of information, as well as proven PIC code, and the magazine EPE have an excellent tutorial on their website.