Weird HITACHI driver + LCD pinout

[izua]

hitachi lcd pinout

Hey guys!
I've got a LCD display with a HD44780A00 driver. It's actually the first time i'm using a display. I got it from a friend who has another friend who's working/debugging public payphones. He got a bunch from the company, since he's an engineer, and i got one

but he got no datasheet or anything. It simply has two columns of pins, each with 7 pins. The columns are on the height of the LCD display. I've looked over the driver's datasheet. The GND pin is connected to the lower pin of the second column. I'm really not able to find out the other pinning. I've made a very simple drawing, with the GND pin as red.

The correspondent pin on the first row is tied to Vcc (checked with datasheet). There's also a small 1 wrote on its trace.

Can anyone explain me the rest of the pins? I've googled a bit, but nothing useful came out. The module doesn't even have a name.

Many thanks,
izua

I've also attached a picture. This is the side with the chips, pins are facing me:

edit, i can't attach the picture. whatever i do, the url gets screwed somehow. If you have the time, here is the link: **broken link removed**

I'm not going to write on it right now, since i'll still have to do some research, but i want to light it at least.. what pins should I connect? Thanks again![/img]

 

[abidr]

pinout display hitachi

if you try to google something like:
HD44780+datasheet
or something like how to drive a HD44780 based lcd
I hope you ll get tons of links.
This is kind of industry standard LCD character module.
Just in case you cant find here is a datasheet of another HD44780 based module, I dont think manufacturer is that important I guess it would be true for almost all (except those having a backlit display)

 

[JohnJ]

7x2 lcd pinout

I don't want to be too negative, but you will be lucky if you find detailed application information. I have had very little luck with non standard displays. I have quite a few I have never gotten working. Most of the brands are companies I can't even find. Most of the unusual displays are custom made and the only data sheet is internal to the customer.

I was told that there is very little standardization in LCD displays. That chip they use is generic (that Hitachi chip) but how it's hooked up differs with each display type. ( The guy who told me that is involved with making a universal driver chip that will help force the standardization of the glass product. He said that is a big industry problem.) I found you have to reverse engineer the whole module if you don't have the data sheet for that exact display.

That being said, there is a standard module type that has 13 or 14 pins including power. They have a selectable 4 or 8 bit interface and a standard set of commands. Those are the ones that you can buy in 1x20, 2x20 etc. from Digi-key or Allied.

Try "w**.allelectronics.com". (that's "www") They sell a lot of surplus displays and may have a data sheet for a simular module. Also, try Googling any part numbers on the board. I have actually found stuff like the manufacturer that way.

I have a 640x200 LCD I wanted to use and I found a data sheet, but I don't read Chinese ....

 

[izua]

lcd display pinout hitachi

Well, I thought for a time that it was non-standard, but it was the actually 7 x2 pin standard which i found after a while. Anyway, the problem is now - the connector, how can I wire that thing to the breadboard?

I tried to connect it with a modified IDE cable, that fitted in the breadboard, but I gave up, some pins were messed, and nothing useful came out.
Is there a standardised 7x2 connector? I don't want to solder it, since i know my sodlering skills are poor.

Also, what should i connect at the other end, the one that fits in the breadboard? Socles/bases? or what else?

Thanks

 

[JohnJ]

lcd 2x20 pinout

Personally, when all else fails, I just use individual wires. Matching connectors is always a problem, there are literally hundreds of thousands different types of connectors.

I haven't looked at the chip data sheet yet, but you may be able to buzz out (oops, continuity test) the connector pins to the chip. That may give you an idea which pins are data and which are control pins.

A little logical thinking....most likely the data pins are grouped and in order and the control pins are together. Look at other modules. I have found many many times, people use a common, logical order to pins. Remember, dual rows of pins are usually (but not always) numbered odd on one row, even on the other. This lines them up in order on a ribbon cable. Then some designers just ignore the numbering and run a sequence down one row or the other. That's why checking the connections to the chip might help.

If you are worried about burning anything out, put ~1k resistors in series with your interconnections, if there aren't already resistors on the board. That limits any shorts or reverse polarity connections to 5ma (at 5V). Most chips will handle that.

I have found one re-occuring problem when people (starting with me) first try to get displays working.....There is usually a command (or pin) to blank and unblank the display! I have more than once rescued someone who has spent days trying to get their display working by pointing that out!! (Did you turn it on?) I myself found that the first time after 3 days of frustration at not even getting my (known) display to do anything.

My suggestion is to figure out likely pins, and try the commands that other modules use. Study the commands to start these other modules. On the common one, the first command sets the interface type (Intel or Motorola) and whether the data is in 8 bits or 2 x 4bits.

 

[abidr]

hitachi lcd weird

All you need to do is spend time in thinking, making an electronics circuit is like solving a mathematical problem, you dont just jump to the answer.
Solve the whole problem bit by bit.
Here are a few pic thats would give you some food for thought how to solve "interfacing LCD" problem.

 

[itsahc]

2x20 lcd pinout

Hello my friend.....Anybody knows where to get the cheapest Hitachi LCD?How much you buy?Plz reply to my email itsahc@gmail.com ......If you can get the cheapest one,why pay more

i want to share something about the Hitachi LCD.I have use it and there are no problem.it is easy to initialize with PIC.Right now i use Mikro C to program the display.MikroC have their own library for the LCD and it is simple.So anybody that first time use LCD,lets try program it using Mikro C.

Before this,i have write the LCD program using manual method.It is hard and the programs is long.As a beginner better use the given library in MikroC.

I can give the schematic if you want

 

[abidr]

hitachi lcd wiring connector

Have you tried ebay?
I have purchased VFD modules(lcd compatible) from ebay.
hopefully a 20x4 lcd will cost around 8-15$