Hello everyone,

I have built a program for driving the Nokia 3310 LCD. I bought 2 of these LCDs recently, while I had another older one with me(without the plastic frame). Now I am facing a problem interfacing these new LCDs that the display is garbled on both. The older one displays correctly (as in Proteus):



What I am getting on both new LCDs is:


The older LCD:


see also the difference in graphics display for older & newer:
http://lh5.ggpht.com/_Njeu3g-U...oard04.jpg
http://lh6.ggpht.com/_Njeu3g-U...oard05.jpg

The newer LCDs are not displaying the top 2 rows of the image & the last 11 rows of the LCD are always filled with random(?) dots. I also think the LCD is writing some data off-screen as some characters are not visible at all. I am using 5V for all the LCDs (according to some websites) & here's the (standard) initialization:

 lcdcmd(0x21);		// Activate Chip and H=1.
lcdcmd(0x80 + 90);	// contrast value (0 to 127): 60 enough for old LCD & 90 for new
lcdcmd(0x13);		// Adjust voltage bias.
lcdcmd(0x20);		// Horizontal addressing and H=0.
lcdcmd(0x09);		// Activate all segments.
clrdisp();		// Erase all pixel on the DDRAM.
lcdcmd(0x08);		// Blank the Display.
lcdcmd(0x0C);		// Display Normal.
pixelXY(0,0);		// Cursor Home.
 

The commands for setting contrast work (but different values for old & new, as you can see above)

So finally here are my queries:

1) I suspect it is some different controller than PCD8544 (http://www.edaboard.com/ftopic324477.html). Is anyone aware of a different controller than this in Nokia 3310 LCD?

2) Is 5V safe for this LCD/controller? datasheet says 7 V is absolute max.

3) I saw some people talking about setting an offset. What is it & how to use it? Cant find anything in the datasheet...