Erratic Lines on Graphic LCD T6963C

MadMax

Hi All,

I'm using:
Mega128 @ 8MHz ceramic osc
Graphic LCD (T6963C) on Port A and Port C.
(Lumex 240 x 128) LCMS240128GSF
I'm writing to the display fine, but occasionally I do get some stray lines when writing to the display. I don't have any interrupts or timers running.
I found this thread: http://www.mcselec.com/index2.php?option=com_forum&Itemid=59&page=viewtopic&t=2478&highlight=t6963c

Can anyone comment on whether this is worth trying or if they've had similar experiences.

Thanks in advance.

Max

jboavida · Joined: 12 Feb 2005 Posts: 84 Location: Portugal

Hi,

I had a similar problem but with a KS108 display.
Maybe it can help you

Check this:

http://www.mcselec.com/index2.php?option=com_forum&Itemid=59&page=viewtopic&t=2188&highlight=

If you can find similar code in the T6963C library maybe it can help.

Joaquim

beamer · Joined: 08 Jan 2007 Posts: 44

juanen · Joined: 22 Oct 2006 Posts: 14

fuse jtag activated: NO
fuse m103 compatibility: NO
use m128def.dat

other solution in crystal fuse, internal crystal no problems but use external crystal, use last fuse external crystal, not other.

Kasch · Joined: 18 Jun 2005 Posts: 33

i have the same problem with a T6963C-Display on 240x128

latest bascom-full-version
m64
dataport A
Controlport C
8Mhz extern crystal
fuse jtag activated: NO
fuse m103 compatibility: NO
all wiring are correct, software 100times examined

text displayed very good, but with grafic is only mismatch...i have no 3k3 resistors at home, but i can't resists, that only hand added resistors are the only solution...who fixed the problem without this?
thank you

chr-mt · Joined: 25 Feb 2005 Posts: 128

Hi,
seems that the timing for Grapic LCDs is critical.
I had success with pullup resistors with the one Display,
but tried on different Display and it didn't work.
I found, that signal quality on the datalines was not very good and had DC- offset.
Make shure you use short cables.
Just for testing, you can try to tell bascom that you use a higher crystal frequency than you actually do, like beamer said.
For Example, if you use 8MHz, set: $crystal=16000000
This will force Bascom to make the timing slower.
All your Wait commands will also be slower, and also Uart,
so this is only a trick, to find out if your Display-Hardware and your Program are OK.

regards
Christopher

Kasch · Joined: 18 Jun 2005 Posts: 33

i try this, but nothing is better. it stills graphic trash..

chr-mt · Joined: 25 Feb 2005 Posts: 128

Hi,
maybe you should try to increase stacksize ?

Christopher