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Erratic Lines on Graphic LCD T6963C

 
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MadMax

Bascom Member



Joined: 24 May 2005
Posts: 53
Location: Kingston, Ontario, Canada

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PostPosted: Fri Jan 26, 2007 10:43 pm    Post subject: Erratic Lines on Graphic LCD T6963C Reply with quote

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
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jboavida

Bascom Member



Joined: 12 Feb 2005
Posts: 84
Location: Portugal

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PostPosted: Sat Jan 27, 2007 2:25 pm    Post subject: Reply with quote

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
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beamer

Bascom Member



Joined: 08 Jan 2007
Posts: 44

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PostPosted: Sat Jan 27, 2007 6:38 pm    Post subject: Re: Erratic Lines on Graphic LCD T6963C Reply with quote

MadMax wrote:
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=3476

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

Thanks in advance.

Max


Max: I had a similar problem, if your lucky it could be the same issue.

If the issue is timing you can simply tell the compiler that you are using a 12Mhz crystal for instance, in this way you will fool the compiler into increasing delays. Try this first before changing library files because if it does not fix the issue, you may have a different kind of problem.

Regards
Chris
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juanen

Bascom Member



Joined: 22 Oct 2006
Posts: 14

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PostPosted: Sun Jan 28, 2007 12:23 pm    Post subject: Reply with quote

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.
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Kasch

Bascom Member



Joined: 18 Jun 2005
Posts: 33

PostPosted: Sat Jul 07, 2007 5:10 pm    Post subject: Reply with quote

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
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chr-mt

Bascom Member



Joined: 25 Feb 2005
Posts: 128

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PostPosted: Sat Jul 07, 2007 5:30 pm    Post subject: Reply with quote

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
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Kasch

Bascom Member



Joined: 18 Jun 2005
Posts: 33

PostPosted: Sat Jul 07, 2007 5:54 pm    Post subject: Reply with quote

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

Bascom Member



Joined: 25 Feb 2005
Posts: 128

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PostPosted: Sun Jul 15, 2007 12:32 pm    Post subject: Reply with quote

Hi,
maybe you should try to increase stacksize ?

Christopher
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