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Help with a connector (Newb Question)

Gary Israel

Dec 17, 2017
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This is my first post and I am pretty much an electronics newbie, so please forgive any stupid questions or assumptions I may throw out there!

So, I have small project that I am working on to replace an old LCD display, it is a 2x16 line non-backlighted type that is very hard to read. I'd like to replace it with a backlit new one. This is from an old photographic film processor so I am not sure if the right connector is available or not. I am trying to put together a new LCD/Flat Ribbon ICD Cable/Male socket connector, rather than just cut and splice the cable just in case I screw it up I can fall back to the original setup.

I have the right ICD ribbon cable, but i need a connector that I can attach to the cable and plug it into the processor's main board. Below are some pictures. I would appreciate it greatly if someone could help me with the connector type and a supply source.

Thanks!

Male connector and ribbon cable:
2017-12-16_10-26-46 by gdi2003, on Flickr

The main board socket it plugs into (labeled "Display":
2017-12-16_10-27-45 by gdi2003, on Flickr
 

hevans1944

Hop - AC8NS
Jun 21, 2012
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Visit this Google results page and pick out something you like. The kind that folds the ribbon cable back on itself to form a strain-relief is my preference, but the straight-through and then squeeze to puncture the ribbon insulation also works well if not too many remove/re-insert cycles. You can also adapt a female DIP receptacle, attached to the ribbon cable, by purchasing rows of pins that insert into the female cable receptacle on one end and into a PCB socket on the other end. Not the best solution IMO but it does work.
 

Gary Israel

Dec 17, 2017
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Great - thank you both!

I will order some dip connectors, and I'll figure out which is the fold over type to get the strain relieve benefit.
 

Gary Israel

Dec 17, 2017
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I have ordered a crimper, Spare LCD, and a few dip connectors. Now I need to think about the connections to the LCD. My old LCD has the pins located on the end of the board (see photo below), in a dual 2x14 configuration. It is a non-backlighted LCD - thus the 14 pins. All the new LCDs I have found have the pins in a single row along the long edge and have 16 since they are backlit. I plan on wiring the backlight pins directly to the power supply and ground of the processor.

My question: is there a graceful way to transition from the 2 row setup and small ICD cable to the long/wide single row of the new LCD? Or do I just solder wires straight to the header pins? And I guess another option would be to add a small bread board to the processor and just rig it all in, but I'd like a more clean and tidy setup, if reasonable.

Thanks!

Old LCD setup:
2017-12-17_03-46-02 by gdi2003, on Flickr
 

kellys_eye

Jun 25, 2010
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The odds on you ever dismantling the gear any time soon are remote so I'd go for a neat soldering job and box it up.
 

Gary Israel

Dec 17, 2017
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I think you maybe right Kellys-eye. I'll stew on it a day or two and make my decision....

Thanks for helping!
 

dorke

Jun 20, 2015
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Here is another issue you have to deal with:

This looks like a mid 80s product.
In that time there were a few different types of LCD driver controller IC chips,they were not compatible.

Today there is a Defacto industry standard which is compatible to the Hitachi HD44780 LCD display driver chip protocol.
i.e. most(all?) new LCD display are this type.

Before you start,
identify which IC controller chip you have on that old LCD display and verify it is compatible as well.
 
Last edited:

Gary Israel

Dec 17, 2017
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Thanks, Dorke, I was wondering if it may make a difference. It looks like it's an HD44100H rather than HD44780. I think the pins are the same - though V0 is labelled VL on the old one. Even if it doesn't work, I don' think it would hurt the processor - maybe blow up the LCD? Or am I wrong?

I ran across someone who did this and it worked and did no harm. Here is the back of the LCD...

2017-12-18_09-07-29 by gdi2003, on Flickr
 

dorke

Jun 20, 2015
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You have a 2 IC implementation :
the controller is actually the Samsung KS0066F and the display driver is the Hitachi HD44100.

Since the interface (14 pins) is the same, nothing will be blown up or damaged.
The problem would manifest itself by wrong/garbled characters displayed.
It is a software comparability issue.
Go ahead and try it,it may work if you are lucky,
or, checking for comparability of the register set is possible if you have the time and patience...
HD44780U KS0066F
Couldn't find any reference to comparability on the web.
 

kellys_eye

Jun 25, 2010
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The datasheet for the HD44100H states that:

Capable of interfacing to liquid crystal display
controllers: HD43160AH, LCTC (HD61830/
61830B), LCD-II (HD44780S, HD44780U),
LCD-IIA (HD66780), LCD-II/E (HD66702),
LCD-III (HD44790), HD66710

so you may be in luck!
 

Gary Israel

Dec 17, 2017
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Well, I was able to change out the LCD for a backlighted one. Ran into a couple of glitches - like learning how to crimp Dupont connectors with a crap crimper! So I used the Duponts with the plastic header connections on the LCD. I found a crimp DIP connector that looked like it was going to work out great, crimped the ribbon cable and plugged it in - but nothing worked.

I investigated and found the DIP pin configuration was opposite the old one. The old connector had the outside wire at pin 1 on the upper right corner, the new had the outside wire connected to what would be pin 16 on the old connector when held in the same orientation. So, I had to crossover each pair of ribbon wires so the header housing connectors look a bit messy, but it works! Here is a pic...

2017-12-24_09-55-32
 

dorke

Jun 20, 2015
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Nice,
You were twice lucky,
mostly the fact that the first wrong crossed crimp didn't damage anything.
 
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