I recently purchased used from a local surplus vendor a "Lexmark T612/T622 Display with Keypad and Control Panel", model # 11K0627/11K0628.
The PCB inside has Optrex silkscreened on it.
I just got off the phone with technical support @ Lexmark, and despite reassurances that this device would only be used for experimental purposes in pursuit of my hobby, they would not release to me any details concerning the 5-pin connector on the back, nor the communication protocol it uses.
I am contemplating getting in direct contact with a Lexmark Product Support engineer, but not until I have exhausted other possibilities.
I also have an email in with Optrex, so maybe they might shed some light on the situation (they did respond to my email, so we'll see to where it leads).
The display itself looks to be a 20x2 LCD without backlight, possibly a HD44780 controller, but that is not really known as the controller "IC" itself is expoxy-blobbed onto the PCB, with no markings. In between that IC and the 5-pin connector (which is also connected to six pads for the buttons), is a 20-pin SMT IC (SOIC, I think) - which seems to have "house markings" of some sort; I don't have the numbers I saw on it handy right now. Suffice to say I believe it is a microcontroller of some kind.
I am looking for ideas on how to work with this device (short of buying the Laser Printer it is for and doing a man-in-the-middle attack, which I suppose is a possibility). I've also contemplated social-engineering my way to speaking or otherwise communicating with a product engineer at Lexmark; I've let them know I was willing to pay for the specification, but that didn't sway them.
Only 5 pins? Heh...two have to be power+gnd so I'm betting it's a 3-pin SPI job or something. I'd vote for the man-in-the-middle attack with a logic analyzer.
Unless that would be illegal, in which case I would recommend no such thing!
Actually, Osgeld, there are, but I don't have the device or information in front of me right now. I will post more information (and scans/pics) later tonight when I get home.
With that said, my research on the numbers (except what I posted - which were actually numbers from the enclosure, not the PCB) didn't bring up anything at all, which leads me to believe that any numbers are likely "house" numbers, internal only to Optrex and/or Lexmark.
When I got home, I pulled one of the modules I had purchased (I had purchased two), which wasn't the one I had looked at earlier; upon opening it, I found it had a different interface chip on the back that the 5-pin connector interfaced to. Looking up other information on the back of that display, I found this thread on the AVRFreaks forum:
Which may be related; I have yet to apply power to my LCD, maybe I will get to it later...
Anyhow, in the article on my site there are pictures and such of my modules which will hopefully help; I noticed on the second module, the IC was a Phillips IC (a microcontroller, perhaps? Or SPI/I2C interface?)...
assuming the lcd driver is under the epoxy you can trace out the lcd pins and the switch pins
if you can find a stand alone lcd by the comany with a similar model number you might have a shot of rigging it
I got lucky on mine, a Compaq prolient server module, it has a atmel clpd device a small mcu and some glue, pop the two program chips out and solder in some ribbon cable and bob's your uncle
Personally, I am hoping to use the interface it came with, rather than hacking in a parallel one - if that is possible; I am not sure it is worth my time and effort to deal with getting a parallel interfaced glued on, especially as it is only a 16x2 (not 20x2, as I though) device, with no backlight (I only paid $4 each for these). If I can get the 5-pin interface working, though, then it becomes a different story (and maybe I can use the buttons, too!)...
Thank you! That's the kind of information I was looking for; at least now there is a pinout I can reference. I hope this will help lead to a communications answer; looks like I may be playing a little with this display this weekend (if I can find the time)...
Quite possibly! Between something like that, the pinout, plus on that other thread at avrfreaks someone posted a possible LCD driver IC candidate (the epoxy blob) which uses I2C that they said may be similar, it might all come together - but there's more (keep reading).
Looks like a standart i2c protocoll with an interrupt line to get micro-controller attention to when someone press some button?
That was my thought...
A few minutes ago I spoke to an individual who works for a company here in Phoenix that acts as the representative for Optrex products. He was interested in what I was planning on using the display for (I mentioned my hobbyist level interest, the Arduino, plus my UGV project and VR/AR interests); he said he would pass the information on the individual who was handling helping me possibly get specs on the display (whom I've been communicating with via email); I had also alerted them on the article on my site and pictures I took, so that may help them - maybe they will provide further information on the display? I certainly am hoping they do!
Just wanted to let everyone know that someone by the name of Enif, over at the Electro-Tech forums, made some progress on communicating with this LCD and control panel. Check out more about it over on my site:
Something to note: Apparently, the pinout given earlier by copiertalk is inverted in some manner (perhaps the pinout shown is for the main PCB in the printer, and not the PCB for the LCD?).
Something else to note: I really need to get one of these...
Thanks again to Enif for clearing this up and figuring it out!
