LCDInfo.com

http://www.lcdinfo.com
It is currently Fri Mar 29, 2024 12:40

All times are UTC + 2 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
PostPosted: Mon Jul 31, 2006 1:06 
Offline

Joined: Sat Jul 08, 2006 17:49
Posts: 25
Hi,

having finally fixed communication problems with the LPT port (now I can read the status register of the T6963C) I have some problem with initializing it.
I tried to follow step by step the initialization procedure published on the "DMF-5000 Series" Manual (that's a bit confused I think) but if I write a simple "A" on the screen I only get a blank display.
What is not clear to me is the setting of graphic home/area and text home/area.
The format of my display is (maybe) a bit strange: 128x112 pixels, and the font size is fixed by hardware at 8x8 equipped with 8K RAM.
Then if my calculation is correct, it should be 16x14 characters.
My initialization procedure is the following:

Graphics Home Address: 0x0000 (command 0x42)
Graphics Area Set : 0x0010 (command 0x43)

Text Home Address : 0x1000 (command 0x40)
Text Area Set : 0x0010 (command 0x41)

Mode Set : command 0x80
Cursor Lines : command 0xA7 (8 lines)
Display Mode : command 0x9F

For each writing there is a status check as required.
After the initialization I try to write a character ('A') on the screen at 2,2:

stat. check
0x0202 --> command 0x24

stat. check
0x21 --> command 0xC0

The display is perfectly blank ! (the contrast is ok because when I reset the LCD a black line appears clearly).

What's wrong? where am I making a mistake?
I also tried with LCDInfo but nothing.

Thanks, regards.

Bob


Top
 Profile  
 
 Post subject: Contrast is negative!!
PostPosted: Tue Oct 31, 2006 17:26 
Offline

Joined: Tue Oct 31, 2006 17:09
Posts: 1
hi, sorry my English, but I will try, I was with a similar problem, after 4 days I got to discover reading one of the reply, in my case it was the same contrast, in the datasheet he didn't speak that the voltage of the contrast should be negative!! and what is worse, when you places a positive voltage (0 up to +5v) he gets to see to adjust the contrast of the line of the reset!!, however to work of truth the contrast it should be negative! among (0 up to -5v)!! give right it worked!!


Top
 Profile  
 
 Post subject:
PostPosted: Tue Oct 31, 2006 18:29 
Offline

Joined: Sat Jul 08, 2006 17:49
Posts: 25
Well...the contrast voltage applied is -8 Volt given with a MAX232 powered at 12 Volt.
Since I didn't get a solution so far, I put the display "in the corner" and made experience with HD44780 displays that are far easier to use.
I hope that one day somebody can give me a clue to make it working.
Thank you, regards.

Bob


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC + 2 hours


Who is online

Users browsing this forum: No registered users and 23 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group