From your description (if i've interpreted it correctly) it sounds like an issue i've also encountered.

In my case, it was down to some of the CLDCD register settings that Sharp had specified for that particular LCD being incorrect. These are contained within the structure:-

/* Sharp LQ035 portrait mode ADTFT display parameters */
const structLCD_parameter structSharp_LQ035_LCD =
{
21, /* Horizontal back porch */
11, /* Horizontal front porch */
13, /* HSYNC pulse width */
240, /* Pixels per line */
3, /* Vertical back porch */
4, /* Vertical front porch */
9, /* VSYNC pulse width */ <------ Change this value here from 2 to 9

320, /* Lines per panel */
0, /* Do not invert output enable */
1, /* Invert panel clock */
1, /* Invert HSYNC */
0, /* Do not invert VSYNC */
0, /* AC bias frequency (not used) */
BBP8, /* Bits per pixel */
5213000, /* Optimal clock rate (Hz) */
ADTFT, /* LCD panel type */
0, /* Single panel display */
1, /* HRTFT CLS enable flag */
1, /* HRTFT SPS enable flag */
50, /* HRTFT LP to PS delay */ <------ Change this value here from 9 to 50

3, /* HRTFT polarity delay */
14, /* HRTFT LP delay */
34, /* HRTFT SPL delay */
100 /* HRTFT SPL to CLKS delay */ <------ Change this value here from 209 to 100
};


Hope this helps

Gary

hi,
I had the same probleme (If I undertsood well) and this is the answer I get from logic

Quote:


Hello Bruno,

There is a known issue on the LCD3.5-QVGA-10 display kit that exhibits
the symptoms that you described below. Logic is currently in the
process of releasing a PCN for this kit that will detail the process for
getting the kit repaired. If you'd prefer you can make this mod
yourself with the three steps below by referencing the display kit
schematic (http://www.logicpd.com/do...8/1000191_revD.pdf):

1) Remove Q1, this will result in the backlight always being off

2) Because of this Q2 will need to be removed

3) R2 will need to be populated with a zero ohm or have the pads
shorted.

In this case the backlight will always be on.

If you require a more detailed description of the fix one can be
provided. Please keep in mind any modification that is done to the
display kit will void any warranty that was valid on that display kit.
Please let me know how you'd to proceed.

Thank you,

Aaron Stewart
Embedded Platform Solutions
Technical Support Engineer
http://www.logicpd.com


-----Original Message-----
Subject of question: Display "Ghosting" on LCD3.5-QVGA-10 LCD Module
Description:
Hi,
I have using an LCD3.5-QVGA-10 LCD Module via the SDK-LH79520-10
application board.

Here is my problem: In lolo, when I use the following command
"video-open 6 16", I receive an error:
Quote:

losh> video-open 6 16

Initializing display: width: 240 height: 320 bpp: 16 disp: 6 timeout
command failed
usage:
video-open <display> <bpp>
open the default video device
Supported displays:
0 == LQ039Q2DS53 1 == LQ057Q3DC02
2 == LQ121S1DG31 (12.1) 3 == LM057QCTT03
4 == LM5Q321 5 == LQ64D343 (6.4)
6 == LQ035Q7DB02 (3.5) 7 == LQ10D368 (10.4)

Supported depths: 1, 8, 16, 24

example: video-open 5 16
losh>

but it seems to work because the screen becomes green with a black
cursor on the upper left corner.
When I use "draw-test" or "draw-flag" to display an image, it works but
the lower half is flickering and unstable and it ghosts other part of
the image.
If I move the cable the display moves too.

When I run linux (from lineo), I have exactly the same probleme!

So is it due to a defective screen or cable? if it does how can I get a
new one (it is a blend new Zoom kit)

If it's an other probleme, what can i do to get a stable display?

Thanks a lot
Bruno

But I will try garyp structure changes
bye

hey garyp,

where is this structure you are talking about? please let me know. Also "funtest" is a command of LoLo, and the output is as I mentioned previously. I try video-open+draw-flag and other LCD testing commands, the display is no good regardless.

also bruno,

I have a rev K LCD screen, so I am assuming that the problem you are referring to does not apply to me.

Thanks both.

Posted By tozyagcilar on 19 Apr 2005 1:5 PM


also bruno,

I have a rev K LCD screen, so I am assuming that the problem you are referring to does not apply to me.

I also have the rev K screen (it is written on the back of the screen on a sticker)

I didn't try yet the hardware changes
bye