which pins on 7s display?

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi all,

I am quite a beginner in the world of arduino, in fact, I have never actually seen one for real, but my order's on.

So now I bought a ?4 pocket calc with 8d display (7s) and I believe an M and an E.
I wrecked the display out (it was connected with those tape-wires) but I have absolutely no idea what pins I need to use the 2 most right digits and the most left one. here's some info:

there are 8 digits, those ' for in 1000 and I believe a comma.
there are 35 pins on the downside, nothing on any other,
there is no mark, no number and no model on it
there are 2 tapes which I think were to fill the space behind it.
the most right wire was not connected (?)
the board I took it off says:

LFa
Sn-Ag-Cu
KC-330-10 REV02

and somewere else

XY11628

and somewere else

0328

by the way, a very strange thing:
they built in an off-button, but there's no button for it and you need to connect 2 metal dots (K1 and K3) with a shortcutted pocketpower (or just a rainbow wire ;D I did it like this) to turn it off.

If you want to, I can upload a picture of the display.

I've heard something about common and cathodes and anodes or something, but I have absolutely completely no idea what that means.

If anyone could help me get my display to work, I would really appreciate that.

Thanks in advance,
masteRens

PS: if my english is crappy, I'm sorry for that. I'm Dutch

2

wow, thank you. I should have known that part about Sn-Ag-Cu, because my friend has Element Memory ;D

You were right, I wrecked it out of a calc that was for sale in my country (holland) as a HEMA-calc. But, think think, HEMA has no factories, so they obviously put their own mark on the box and put it in the store. It's probably made by some $0.001/h factory in some far country (n.o.).

Nope, I can't look into it. In fact, It looks like the wires stop just before the actual display. But it can be an optional trick.

I think I will upload some pictures of it in a while. Problem is, I can't find a single battery in my house, and my cam is empty :-/

Still, thank you for your help.

masteRens

3

I've heard something about common and cathodes and anodes or something

They refer to LED displays, is your display LED or LCD? If it is LCD then you have little chance of using it in an arduino.

4

once again, I have completely no idea
But I think it's led, because it is segmented (I hope, I can't see them when they're off, but when the calc WAS (hehe) on I could see them even though they werent supposed to be on. I think it wouldnt display segment-style digits if it were lcd)

5

Could you see it in the dark with the numbers glowing? If so it is an LED, if not it is an LCD.

6

In fact, I have not tried, but I fear the worse...

PS: I tried to hold the pins to the original spot, and after a while trying I saw two segments from different digits pop on for a moment. Is that a good thing?

7

Were the digits bright or dark against a bright background?

8

black/gray against yellow/green background. Good or bad? [smiley=shocked.gif]

9

but... can lcd be segmented?

10

I found this library called LCDLibrary. It looks like mine, but mine only has a few more pins (35 instead of 12) so I could just use that lib and figure out if the screen requires the actual numbers or something else? Or is LCDLibrary only for displays with way more possible chars?

11

The Library is for LCD displays that have there own controller chip on them. Your LCD does not. Therefore it is of no use to you. You could build a controller chip onto your device but it would cost many times more than buying a proper LCD.