HD66710 LCD pinout

[gbttun]

Hello,

I'm attempting to get a LCD to work with a shield for the Arduino. The shield (Argent Data Systems' Radio Shield) can support HD44780 compatible LCDs, and the HD66710 is supposed to meet that requirement, though it has 6 more lines in than the HD44780. I know which pins on the HD66710 do what, but they run through another microcontroller, BU12445, for which I cannot find the datasheet online.

The best help I have found so far is this Polish site, http://www.elektroda.pl/rtvforum/topic1099191.html
The post's creator's pinout is pretty helpful; I've been able to (turn on?) one row of characters by hooking vcc up to 5V. However, he suggests that the best way to proceed is to solder leads onto the legs of the main microcontroller, but I want to use the traditional ribbon cable output.

What steps should I next take?

[meseta]

These are from old printers right?

Are you saying that you would like to use the pins of the HD66710 instead of interfacing through the BU12445? If so, and if there are no handy pads to solder pins to, and if you can't use the BU12445 (can't find a datasheet), then you will probably have to solder the ribbon cable onto the legs of the chip.

Whether you have to somehow also disable the BU12445 I don't know, it seems to me that it might try to conflict with the operation of the data lines if the chip is powered.

[gbttun]

BANNED, thanks for your response!

Yes, the LCD was taken from an old LaserJet. On the Polish forum, the author was able to operate the LCD in the manner you described, by soldering wires directly to the HD66710. I would like to use the LCD's traditional I/O (the ribbon cable that connects it to the control panel) to communicate with the shield.

In his post, the author's pinout shows which pins (the important ones) on the HD66710 are connected to the BU12445, and also which pins on the BU12445 connect to which wire on the ribbon cable. Unfortunately, he wasn't able to find out how the pins of the BU are internally connected, and there is no published datasheet floating around on the Internet.

Is there a way I can connect the pins, or have I hit a brick wall?

[gbttun]

This may help clarify the situation I'm describing:

http://www.google.com/imgres?q=hd66710& ... 80&bih=661

[meseta]

This page: http://www.seekchip.com/icstock-B/BU124 ... 45358.html seems to be saying that this is some sort of USB hub with a microcontroller! Not sure if I believe this page though, seems suspect to me.

So the main issue is that we don't know what the BU12445 is doing, it might be a microcontroller, or some kind of interface chip. Without knowing what t he BU12445 does, and without its datasheet, it's unlikely that you will be able to use it. I think your best choice for getting the LCD working is by connecting directly to the HD66710, either by soldering onto the pins directly, or finding a nearby pad.

[pottereric]

Did you ever figure anything else out about the LCD? I have the same one and I'd love to hook it up to an arduino.

[gbttun]

Hi pottereric,

Unfortunately, I haven't found out anything about that interface chip. I found some junked electronics with 16x1 displays similar to the type that the adafruit store sells (16 pin row of headers that uses conventional HD77780 communication), so I use those in my project.
I'm sorry that I can't be of more help, but if you do manage to crack the nut please post. I still have the part, and would like to get it to work if I can.
As a sort of consolation prize (totally uncalled for but hey maybe it'll help someone), this site: http://web.alfredstate.edu/weimandn/ has some pretty useful information on how LCD addressing works. Since the LCD I use is cheap, I needed this site to learn how to use all 16 characters instead of 8.