OPTREX DMC-40218 LCD from 1988 - It's Alive!

I mentioned (injected) into this recent thread that I had this old LCD from many years ago. As a result of the thread, I spent some time actually testing it out and...it works! There is no backlight, as I knew. Vee is tied to ground (may futz with that) and I didn't have to do anything special with R/W. Used a 4-bit interface and an Arduino hd44780 library to test it out. As a couple of folks suspected, there really was nothing special about the interface, it is just old...going on 31 freaking years old, but...EasyPeasy.

From the data sheet, the stamped code indicates an October 1988 manufacturing date. As I recall, I purchased it from BGmicro. When I last looked at this (maybe a couple of years ago), I could find very little info, however, last night and this morning, I found lots of info including the data sheet and user manual and everything I needed. There is some code out there that toggles R/W and RS and I suppose I may find that such is needed in some cases, but for now, I am .

For anyone else who might come across one of these, I offer the following links:

One page drawing: Note carefully the pin outs on the interface. Your board may have a socket or a ribbon cable or two ribbon cables, like mine. With regard to the double rows, Pin 2 is across from pin 1 and so on. Do not read it like a normal IC where you go from pin 1-7 and then across and back up from 8-14.

Datasheets: Lots of these online, including here.

**broken link removed**: Not just for this board, but it is included in there.

That's exactly the same as mine, except the date stamp is 88Y2N1 on the one I found (the other is in a box somewhere?), I used it in my PIC Tutorial along with smaller LCD's, so it has wires to a ten pin Molex plug and simple plugs in the LCD tutorial board. I haven't used it this year, but I'm pretty sure I did last year - by using the plug-in capability I checked out a wide range of different LCD modules from 2x8 to 4x20.



I'm pretty sure mine came from BGmicro as well - it certainly sounds familiar. And as you say, no backlight - I don't think any of my old ones have backlights?.

I don't know why I am amazed by this old stuff but I am. Yours was made ~ two weeks after mine and 31 years later we are talking about it and they still work...

I can't be sure I bought mine from BGMicro but it is what I recall. BTW: I see **broken link removed** that they are still around (assuming they are the same company) and they have a 40 X 2 LCD with a backlight for US$8.55 (or ~ two $bucks vente millenial caffe latte supremos with soy and tofu froth).

I can't even remember why I bought it - some sort of terminal...maybe to interface with my KIM-1 which supported a 20 mA loop TTY - not sure, but I am sure that I never had enough time to learn and spend on stuff for the heck of it (not being employed in an C or EE field) and I really do appreciate that now, I can mess around with whatever I want to and whenever I want to.

DrG said:

I don't know why I am amazed by this old stuff but I am. Yours was made ~ two weeks after mine and 31 years later we are talking about it and they still work...

I can't be sure I bought mine from BGMicro but it is what I recall. BTW: I see **broken link removed** that they are still around (assuming they are the same company) and they have a 40 X 2 LCD with a backlight for US$8.55 (or ~ two $bucks vente millenial caffe latte supremos with soy and tofu froth).

I can't even remember why I bought it - some sort of terminal...maybe to interface with my KIM-1 which supported a 20 mA loop TTY - not sure, but I am sure that I never had enough time to learn and spend on stuff for the heck of it (not being employed in an C or EE field) and I really do appreciate that now, I can mess around with whatever I want to and whenever I want to.

Click to expand...

I bought mine with the intention of making an add-on RDS unit for my FM Tuner, a guy in Canada did a PIC design based on a specific RDS chip (which I was able to source easily, as a spare part), and he listed the BGmicro LCD's which was what he used.

In the event I never finished it, as I hardly ever used the tuner, so it didn't seem worth bothering.

If I can find the other LCD it will confirm it was BGmicro, as I'm pretty sure it's still in the original box!.

I just found a small box of the LCD displays. 40x2 with back light.
I remember designing a small CRT monitor for Hitachi (broad cast resolution) and some one came in with a 8x1 LCD display to evaluate. All the engineers spoke bad about the contrast and the price was high and low resolution etc. I was the only one to say "this will kill us". Decades later I was the one designing multi million pixel LCD monitors. Time flies.

Are you sure the two connectors on the right aren't the backlight?

Mike.

Pommie said:

Are you sure the two connectors on the right aren't the backlight?

Click to expand...

Yes, they don't go anywhere

Presumably they also made a version that did have backlighting, and used the same PCB for both?