Murali,

If you are not able to locate the datasheet, what information are you seeking for this LCD? I have successfully attached this LCD to a processor as I explained in an earlier thread on this post. I have gotten another LCD from this company and it is yet a different LCD than the one I received the first time and different than the datasheet. Their information is not correct for the model mentioned in Bill's post or the second one I received.

I found other similar pin diagrams for 4x40 LCDs that did the trick for me. The key lays not only in knowing which pins are for what, but also understanding that these units have two controllers.... one for the top two lines and the other for the bottom two lines. Pins 1-8 are for data (DB7 down to DB0 respectively). In my case I only use 1-4 because I am using 4 bit mode. Pin 9 is the enable for controller #1, Pin 10 is RW, Pin 11 is RS, Pin 12 is Contrast, Pin 13 is Ground (VSS), Pin 14 is VDD, Pin 15 is enable for controller #2 and Pin 16 is no connection. Pins A & K over at the opposite end are for the LED backlight..... A being positive and K being negative.

So to write to lines 1 or 2 on the LCD, you must enable at Pin 9 before your write and to write to lines 3 and 4, you must enable Pin 15 before a write. In the case of BASIC Stamp that I am using, I just specify a different parameter in the LCDOUT command to activate the other enable pin in my outputs to the LCD. The concept should apply in your implementation as well.

Anything I can do to help out, just ask.

Rick