parallel lcd

vontrapp

Hi,

I am using a 1-line 16-character lcd in 4 bit mode (unknown brand, type gdm1601c). Unfortunately it shows only the first 8 characters. Longer data is truncated after the 8th character.

Anybody knows why?

thanks,

Hans

Chris Savage

Hans,
·
·· Often these LCD Displays are 1 line, but need to be configured in two line mode, and the second half of the display is actually line 2.· It sounds weird, but I have a few like this.· I would try that. ·I bet that’s it.· I hope this helps.· Take care.

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Chris Savage
Parallax Tech Support

Benoit

Are you initializing the LCD with a 1 line mode?

My LCD has 2 lines, and I use:
LCDCMD Lcd, %00101000 ' set to 2-line mode with 5x8 font

I think that in the case of a one line, you would need
LCDCMD Lcd, %00100000

Or something similar, according to the Stamp manual 2.2, page 163.

-Ben

vontrapp

Hi Chris,

Thanks for the reply. But how do I write to the second line? data is still truncated after the eigth character.

thanks,

Hans

vontrapp

Hi again,

Just found it, by setting the ddram adres.

Chris Savage

Correct, you have to set the address to the second line and start printing.· So, is it working now for you?· I remember the first time I saw one of these, the only reason I figured out what was happening was I wrote a program to keep incrementing and printing * and eventually the remainder of the display started filling up.· That’s when I realized what was happening and was able to make use of a few such surplus displays I obtained.· Take care.

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Chris Savage
Parallax Tech Support