Mystery LCD Module... help!

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RaduMolasar

New member
Dear gentlemen,

Newbie here...

I just purchased a rackmount server case with included LCD module, but the manufacturer knows nothing of how to connect it.

I've searched all over the net with no luck.

Can anybody shed some light on it? Help!!

The LCD module is installed on (screwed onto) the front cover (panel) door of the server case.

At first I thought it connected to an internal alarm/fan board, but the included alarm/fan board has no such connector... in fact, not connector at all except for fans and temp sensors...


Thanks!

Mike
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RaduMolasar

New member
Mystery LCD revealing...

Hello,

I wrote Densitron about this LCD, and included the pictures.

They wrote back saying it was an LM4162, HD44780 -driven (looks like parallel). That's it.

I include the datasheet.

I'm still bewildered by the 30 pin connector.

With this new info, is there a reasonable chance of getting this up and running? Can someone point me in a proper direction to find suitable interfacing parts (I'm no electronics wizard, so I'll have to go with readily available [or readily orderable custom made] parts) to get this server chassis LCD going?

I have an extra LCD module I could experiment on or send to someone to experiment on. I am prepared to cover reasonable fees (PayPal please!) to get this running! Help!!!

Thanks!

Mike
 

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cosmicvoid

Master
I am skeptical of the info you got from Densitron. The drawing in the data sheet does not resemble the module in your photos.

Can you post the part number from the SO14 chip (next to the 30 pin header)?

Can you peel up the paper label on the large chip and post a part number?

Can you remove the board from the metal shell, and post a photo of the top side?
 
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RaduMolasar

New member
Will do this over the weekend, since these LCDs are at my other house (a 30 mile drive)

Thank you very much for helping me out, Cosmicvoid... I hope I finally see this thing come up to life!

Thanks again and best regards,

Mike
 
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RaduMolasar

New member
New info...

Hello,

I peeled the paper sticker off the main U1 chip and lo and behold:

A Hitachi Japan HD4480A00 (see pics)

The U3 chip next to the 30 pin header reads:

P02SR
DM7406M

There is an "F" symbol at the beginning (maybe a trademark? Fairchild Semiconductor?). See pics. Also, the 0's could be O's, but they look like zeros.

The other chip (U2) reads:

OKI
THAILAND
M5259
0152B01

I also took pictures of the reverse (front side) of the LCD module (please excuse image clarity... The HandyCam is good at video, but not so well at still images).

I also included pictures of how and where the LCD module is installed.


Thanks!


Mike
 

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cosmicvoid

Master
Based on your pix, which I did not evaluate in great detail, I will hazard these new guesses:

Since most HD44780 modules use 14 pin interfaces, I'd bet the first 14 pins of the header are for the LCD interface.

The 7406 is probably the LED driver, kind of a waste of a SO14 unless other sections are used (for what?).

The keys are wired directly to the header, with no processing. The keypad logic is on the other end of the cable.

You can probably verify the LCD interface connections by following the traces from the header, and comparing to the pin numbers of the HD44780, using the data sheet for that chip. The contrast input voltage (Vo - LCD voltage) is provided over the ribbon cable. Do you see a contrast adjustment in the rack chassis?
 
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RaduMolasar

New member
Cosmicvoid,

There is no contrast control whatsoever inside or outside the chassis.

I gather that this LCD display works in conjunction with an internal alarm board, such as the one outlined in the attached PDF (which, in this particular document, also optionally sends status data to another external monitoring serial port), but the included alarm board does not have any header where to connected it.

That leaves me four options:

A) Find the appropriate alarm board (very difficult, since I do not even know where to start, let alone find a matching alarm board with the 30 pin header!)

B) Have a custom USB LCD and/or bezel (or off-the-shelf LCD module + custom bezel) made to similar dimensions, aligned mounting holes, color, etc. (somewhat difficult, since having just one bezel made can be expensive, if even done)

C) Have a custom internal PC board made to drive this LCD module (somewhat difficult, since I would need to find someone who is up to the task as a spare-time project)

D) Forget about the whole thing. (I'd hardly consider leaving this nice blue 2U rackmount server chassis handycapped)

Any ideas?


Thanks!

Mike
 

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RaduMolasar

New member
Hello,

I was searching the net and found this:

http://www.usbmicro.com/odn/index.html

(click on [U4x1 Application Notes] | [App3: LCD] on the left menu tree)

Apparently, this little U421 USB I/O interface can be linked to HD44780 LCD devices.

I have no doubt it could drive the LCD via a USB port (which seems to be the easiest and best choice), but what of the buttons and LED?

Any thoughts?

Thanks!

Mike
 
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cosmicvoid

Master
Ha, very interesting! The pdf file gives the needed info.

You would have a hard time duplicating the function of the alarm board, which obviously has a cpu on it to do the LCD I/F and the fan/temp I/F and a serial port. But there is already a product that does ALL of those things, available from Crystalfontz. Take a look at the serial displays, like the CFA633 http://www.crystalfontz.com/products/633/index.html

The only problem then becomes the bezel, and whether the CFA module would fit the window opening for the display. You'd also have to do a makeshift arrangement for the keys to use the existing holes (or hack the keypad area off of the board you have now, and re-hose the connections to the 633 board). That would void the warranty, so you may still have to get a custom bezel. Or maybe you could use the panel that mounts the display in an empty drive bay, and chuck the external shell.

I am not a user of the CFA serial display products, so I can't advise you on the details, but you could ask in the Product Question forum. Also, realize that you will have to do a bit of programming on the server to utilize the functions shown in the pdf file (i.e. date/time, alarm states, etc).
 
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RaduMolasar

New member
I am a software developer (programmer), so I'd have almost no problem programming the U421 I/O interface, but I would need guidance to wire it up to the LCD module.

Also, I am not sure if the U421 could somehow power the LCD module, and if key input could be captured and the LED driven....
 
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cosmicvoid

Master
If you use the U421 to interface to the LCD module, you could steal 5v from the USB bus for the LCD; but then whad'ya gunna do about the key inputs, the fan control, and the temperature monitoring? Those would be really messy to do PWM control and PWM sensing using the I/O lines, if that would even be possible. You would have to command each change of state over the USB bus, which is a HUGE communication overhead. Or maybe I misunderstand what you want... do you care about fan/temp control?

If you want fan/temperature features, I think the CFA serial or USB 633 modules would be the easier way to go, even if you have to do some mechanical rearrangement. Note that I'm not really trying to plug the CFA modules; it just seems that wheel has already been invented. But maybe, for you, the mechanical aspect is more daunting than the programming aspect.

If you only want the handle the keys and LEDs, then the U421 might be practical, although you'd have to spend a lot of time polling for key presses, as I don't think the U421 will originate a packet when I/O lines change (truthfully, I don't know, as I didn't read the U421 info very far).
 
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RaduMolasar

New member
Thanks for your input, Cosmicvoid...


The truth about this matter is that I really don't need to control temp/fan stuff, as there is already a fan/temp/alarm board inside the server chassis that handles all that (though it has no LCD output interface).

So I really just want to drive the existing LCD module with my own software-programmed menus and stuff like that; I'd just need to somehow "catch" keypad events or "presses" and somehow drive the LED.

I wrote USBMicro about this and I'm just waiting for a reply.

In the meantime, I'll try to find the Oki M5259 datasheet to see what this chip's all about.

If you have time or willingness to remotely guide me out in the process of wire soldering (linking) the U421 (if it's indeed appropriate) to this LCD module, I'd more than gladly make it up to you.

Thanks again for your time and patience.

Regards,

Mike
 
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cosmicvoid

Master
The M5259 is of no importance to your use of the display module. Its just a segment driver for the lcd panel.

I am willing to provide a little 'armchair assistance' to you, but I don't really feel like doing the research for you. Here's what I think you need to do, based on my limited knowledge of the U421 and your hardware:

Dig up the HD44780 data sheet, and note which pins on the chip are for the user interface (e.g. D0~D7,E,RW,RS,etc).

With an ohmmeter, and visual tracing, make a list of which pins on the 30 pin header are connected to the HD44780's inputs.

Look at the U421 pin connection data, and fabricate a cable or something to connect the LCD I/F to the U421 lcd I/F.

Trace the inputs of the 7406 which control the red/grn LED sections to the 30 pin header, and connect those to two unused I/O pins on the U421.

Trace the keypad to the 30 pin header, and assign buttons to unused I/O pins on the U421. I assume that one side of the keys is commoned, and that should be ground. The other key pins will need pullups, to ensure a 1 state with no keypress.

There is a problem with handling keys... its called debouncing, as simple mechanical contacts will give multiple closures over a period of 10~30 mS, until the contacts settle. To debounce, you need to sample every few mS, to tell when bouncing has stopped. This is messy to do over the USB link. You would need to use something like the 14490 to do that in hardware ( http://www.onsemi.com/pub/Collateral/MC14490-D.PDF ). Then you can just sample using a standard windows timer, every 50 mS.

Afterthought: looking at the U421 connections, you will not have enough I/O lines to do this, unless you do some I/O expansion, or use a 4 bit LCD interface.
 
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RaduMolasar

New member
Thank you very much!

I will then proceed to trace and find out what each header pin is for.

I'll get a list ready and post results.

I examined the literature of the MC14490, but I'm not an electronics circuit guy, so I'm just kinda dead on the water with terms such as "pull-up resistors" and stuff of the sort I'm sorta having a hard time figuring out.

I'll do some extensive reading and research and post questions when I'm down and dirty building this stuff.


Regards,

Mike
 
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