Help using this Graphic LCD

It looks like this:

And lights up like this:

It has a part number on it (3C050805A116 , LDAA4ZV14Y1CD), but neither hit on google. It has "Nan Ya Plastics Corp, Made in Taiwan, MV14B REV:B" written on the attached ribbon cable.

It has a total of 26 pins, while it was still attached to the cluster I measured the pins while it was displaying an odometer reading on the graphic part of the LCD, nothing else lit.

  1. 4.38
  2. 2.75
  3. 1.25
  4. 1.88
  5. 3.37
  6. 2.45
  7. 6.27
  8. 2.02
  9. 2.58
  10. 8.07
  11. 8.07
  12. -Ground-
  13. 5.00
  14. 0
  15. 0
  16. 0
  17. 0
  18. 0
  19. 0
  20. 0
  21. 0
  22. 5.00
  23. 5.00
  24. 5.00
  25. 5.00
  26. 5.00

I've had limited success getting it to light up, it has displayed everything (like the 2nd picture) a couple of times, but nothing repeatable.

Any suggestion on what other tests to do to determine the pin configuration would be helpful.


Maybe a scope rather than just the dmm?

I giess it looks like it has driver chips on-board?

Perhaps it's listed here: Mark Products LCD Modules - a company that sells Nan Ya goodies.
Google is your friend :wink:

Manufacturers page:
Select 'Products' in the left column, then 'Automotive Displays'.


I don't have a scope at the moment, over winter break I'll have access to one.

The chip in on the board, it is the Hitachi H8S/2638, so I was hoping it might use the Hitachi protocol that Arduino supports. Pins 12-26 are connected directly to this chip.

The size of the graphic LCD is 132 x 32 pixels.

This spec was on their website for a 128x32:

I sent emails to Mark Products, Nan Ya, and Australian Arrow. I got a reply from Australian Arrow saying they're not sure if it's Holden property, but they were forwarding my email to someone else.

Sorry to be a newbie dredging up an "old" post... But I'm actually in the exact same situation! Trying to do some instrument cluster work (Pontiac GTO / Holden Monaro cluster) and looking to get this LCD displaying something useful... I haven't touched it with a scope yet myself, just unsoldered it a few seconds ago. Any luck getting anything working REBinc?? I LOVE the radar display in the cluster; did you do that, or was it a pic from online? Perfect way to remove the "GTO" text from the faceplate!!

I haven't gotten any further. I can't even get a normal LCD to work with my arduino.

The radar display is my car, I am hoping I can put the radar information on the LCD. What do you want to do with yours?

Well... :slight_smile: First I want to get the gauges working. This would be for either Pontiac Fiero or "generic" GM inputs.. The Tach and Speedo would be fine with their inputs (with a little massaging), but from what I can tell the fuel and temp. are controlled by messages from the GTO ECM. I figure I'll have to scrap the Hitachi processor alltogether, and use the new microcontroller to do speed, tach, fuel, temperature, and then drive the LCD screens. :slight_smile: Lots of processing though... I want to have Odometer of course, but also some "fun" stuff like simple graphics. The 2 little LCD's are no problem, the i2c driver chip Holden has on there is the bigger cousin of the chip I've been using for years to drive LCD screens. It's this main screen that's still got me up at 2am!

I spent some time under the 30x scope counting the pads on the COG driver chip on the glass, and tracing some of the clear "wires" inside the glass to their pins. It's got 310 pads, if it helps ID the thing. All the LCD controller chips I've found so far don't seem to match up. Was hoping some of Nan Ya's other screens would offer some clues, but nothing yet. I'm too burned out to touch the scope tonight, and really you need a logic analyzer to watch all the pins at the same time anyway to mean anything... I gave mine away a while back.. :frowning: It was old and I never used it much...

We have some nice 'scopes at work that I might try if I get real ambitious. While searching for drivers though, I came across a nice LCD screen - Digikey p/n NHD-24064CZ-FSW-FBW-ND for $50, which has 240x64 pixels and would fill the entire screen opening on the cluster. It's a tad bigger than the housing can take without some milling to make it fit, but if I can't get the OEM screen working I'll probably buy that and change the LED's on it. (it comes in white only) It's documented and would be much easier to control I'm guessing...

I (think I) have the same model radar - Escort 8000 something? No idea how to interface that guy though... The guys on the GTO forum want to put Valentine 1 info on the screen, but they haven't been able to hack the GM code yet.

This cluster will first be installed in a "kit" car if it works, I'll most likely do one for my own Pontiac Fiero if I ever get it back on the road this year... I'm hoping to build in a USB or serial programmer onto the main board as well so I can send the guy a file to update it when I add new features.

I honestly haven't touched an Arduino yet, but I've been using Atmel microcontrollers for years. I met the Lillypad lady a while back, she's done some neat stuff with these things.. :slight_smile:

Yeah, I'm one of those GTO forum guys that's clueless. I've learned a lot since I've started, but I keep getting side tracked and running out of time for this project. I have a Valentine V1 and an Escort 9500ci, so my ultimate goal is a custom display for both on the LCD. It's also be nice to read oil pressure and other stuff the ECM knows but doesn't show. I still want it to function normally when the detectors are off though, so I can't put a new LCD in there.

I'm currently attempting a 2nd path, which is to identify the serial signal the radio sends to the cluster, and then see if I can somehow manipulate that into something useful.

Yeah, a different LCD is out! :slight_smile: I think without being able to crack the code in that Hitachi microprocessor, only a hardware "hack" would work.. Like disconnecting the data lines from the Hitachi chip and switching over to the Arduino to display what you want, but being able to switch back "on the fly"... I did notice that if you pull the LCD while it's running it does a re-boot, then comes back with the text on the screen. Which means that the processor is constantly sending the same data over and over.

Are you wanting to have both the "factory" data on the screen and the Radar info on the screen at the same time, or to be able to switch between them? Going the radio data route, does the LCD screen have a dedicated area for the radio display (like only on the left side for example) or can it use the whole screen? (like for a long song title, etc...) I'm wondering if it's hard-coded into the main processor to only allow radio data in a certain area. But then even if it is, the radar data would probably fit there.. Interesting! I would imagine there's a ton of traffic on the Serial data line, watching for just the radio stuff could get interesting. Need to get a real-time OBDII signal sniffer / converter.. One of those scopes at work has plug-in modules for decoding busses like i2c, SPI, etc.. Wonder if they have one for OBD. :smiley:

I'll post any progress I make with talking to the screen if you'd like.. It may be possible to intercept / modify / divert the Hitachi signals.. Or the whole thing may prove to be too hard and I'll give up. :slight_smile: We'll see..........

My plan for the stock LCD was to put a relay on the data pins, and have it flip when ever it sensed an alert from the radar detector, but remain on the digital speedometer while there is no alert. I have 3 extra clusters and an extra radio to work with, but it's been a matter of time.

The radio can do both a small section of the screen, and the entire thing. It takes over the entire display on Volume changes, Track changes, Channel Changes, Voice In, etc, but after it initially changes, it will just display in the left corner, while going back to the odometer in the center of the LCD. So it will Display something like "CD 3 - TRACK 4". I'm not sure if CD and TRACK are hard coded, or if it sends the entire prompt.

Ideally I'd need the choice between 3 arrows (up, down, sides), 4 bands (X, K, Ka, L), and then either a numerical value 1-8 for strength, or some type of strength bar. It also has a bogey counter, but I could cut that if I run out of space.

Interesting... I'd be willing to bet (maybe a Twinkie) that the full-screen stuff like the Volume display is hard-coded in the Hitachi firmware.. The other stuff could very well be sending the full line from the radio to the instrument cluster.. That way future "upgrades" like Ipod docks, XM, etc.. could be added without a re-write of the firmware. But then again, it's GM, so who knows. :slight_smile: Or actually Holden / Australian Arrow. That's probably a good thing!