3.5inch display problem....

Hi all,

I have a pxa270 board with 3.5inch display. It is SAMSUNG LTV350QV_F04. I
have the entire bsp source with me and hence i have the 3.5inch lcd driver
for it.

The display uses spi interface to initialize the lcd.

Now, i have a need to interface the same display with my pxa255 processor
board. So, i am modifying my existing display driver, by referring to my
pxa270 display driver.

I made the spi initialization part of my display. Now, my display is
initializing and i can see some changes or happening on my display.

I included a small test program in the display driver which will display the
color red, green, blue, black and white. Display black, white is ok. But
when i display the color blue, red and green. It is too light. I mean the
shades are very light. I can't predict what's the reason behind this......

The other problem that i am facing is, after the board boots and display
driver is up, i could see only some light colored stripes on my lcd. Since
the display is having touchscreen builtin. When i touch the touchscreen
randomly, i could see that the applications are starting in mydebug windows,
but on the display side, just the strips moves here and there and some color
changes.

I copied the entire lcd settings, i mean the lccr0,lccr1, lccr2 from my
pxa270 driver. Even the spi initializations are same...

i tried, using the same dirtyrectdump algorithms that was present in 270.

I have a working lcd driver on my pxa25 board. But this driver is for
non-spi lcd. It doesn't require any spi initialization nor to select the lcd
chipselect etc...

The one more difference i am finding between this pxa255 and pxa270 is the
alternate function pins L_vsync and L_cs which i can not find in pxa255.

In pxa270 lcd driver they configure L_vsync as input and L_cs as high active
output...

I have not found how to handle these in pxa255 for this lcd....I don't get
an clear idea on this stuff.


What may be the problem??? Since i am a new person to display driver. Hope
someone gives me a good idea on what's happening...

If anyother details you are required to help me, i can provide...

expecting suggestions from you experts soon....


--
Ramesh.c
Innovate Sofware Solutions.
Bangalore.

Steve
Fri Jun 13 16:11:24 PDT 2008

Sounds like you are using an NEC display? I am using one with my PXA270
platform and it was a pain getting the SPI programming of it correct (very
sparse documentation).

I would not try to port the PXA270 LCD display driver back to the PXA255.
There are probably too many differences in the registers and modes. That's
what sounds wrong with the color bar test, you might be using a different
color mode than you think.

You should start with the PXA255 LCD driver, and back port just the SPI
configuration into the LCD driver.

I have not used the PXA255, but I'm sure there are many differences between
the LCD registers, and I would not expect the 270 driver to work without
serious investigation into both dev manuals for the CPUs.

steve ariaza

Rameshchandra
Sat Jun 14 05:51:02 PDT 2008

Yes. I was really fed up with this project. I don't have an document and
commands of this spi display.

Actually we are simulating the spi interface, though 4 pins, reset,
chipselect, clock, data.

I am comparing the driver runtime environment on pxa255 with that of the
pxa270. For the same spi initialization, the same display connected with
pxa270 is working properly, whereas in pxa255 it is behaving as i written in
previous post.

No improvements on this yet... SPI initialization is lcd specific, is this
got anything to do with the processor. Since i am using the same spi
initialization commands that was present in pxa270(working commands), in my
board pxa255 it should work with out any problems right?

I verified my gpio initialization 5 to 6 times... evrything seems to be
fine. If my gpio initializations are wrong, when i enable the lcd controller
it should not respond right? but in this case it is responding...

What is NEC type display??

Anone out there to help in this issue??

--
Ramesh.c
Innovate Sofware Solutions.
Bangalore.


"Steve Araiza" wrote:

> Sounds like you are using an NEC display? I am using one with my PXA270
> platform and it was a pain getting the SPI programming of it correct (very
> sparse documentation).
>
> I would not try to port the PXA270 LCD display driver back to the PXA255.
> There are probably too many differences in the registers and modes. That's
> what sounds wrong with the color bar test, you might be using a different
> color mode than you think.
>
> You should start with the PXA255 LCD driver, and back port just the SPI
> configuration into the LCD driver.
>
> I have not used the PXA255, but I'm sure there are many differences between
> the LCD registers, and I would not expect the 270 driver to work without
> serious investigation into both dev manuals for the CPUs.
>
> steve ariaza
>
>
>

Rameshchandra
Mon Jun 16 02:04:01 PDT 2008

No one else here have time to have a look at this problem??????
--
Ramesh.c
Innovate Sofware Solutions.
Bangalore.


"Rameshchandra" wrote:

> Yes. I was really fed up with this project. I don't have an document and
> commands of this spi display.
>
> Actually we are simulating the spi interface, though 4 pins, reset,
> chipselect, clock, data.
>
> I am comparing the driver runtime environment on pxa255 with that of the
> pxa270. For the same spi initialization, the same display connected with
> pxa270 is working properly, whereas in pxa255 it is behaving as i written in
> previous post.
>
> No improvements on this yet... SPI initialization is lcd specific, is this
> got anything to do with the processor. Since i am using the same spi
> initialization commands that was present in pxa270(working commands), in my
> board pxa255 it should work with out any problems right?
>
> I verified my gpio initialization 5 to 6 times... evrything seems to be
> fine. If my gpio initializations are wrong, when i enable the lcd controller
> it should not respond right? but in this case it is responding...
>
> What is NEC type display??
>
> Anone out there to help in this issue??
>
> --
> Ramesh.c
> Innovate Sofware Solutions.
> Bangalore.
>
>
> "Steve Araiza" wrote:
>
> > Sounds like you are using an NEC display? I am using one with my PXA270
> > platform and it was a pain getting the SPI programming of it correct (very
> > sparse documentation).
> >
> > I would not try to port the PXA270 LCD display driver back to the PXA255.
> > There are probably too many differences in the registers and modes. That's
> > what sounds wrong with the color bar test, you might be using a different
> > color mode than you think.
> >
> > You should start with the PXA255 LCD driver, and back port just the SPI
> > configuration into the LCD driver.
> >
> > I have not used the PXA255, but I'm sure there are many differences between
> > the LCD registers, and I would not expect the 270 driver to work without
> > serious investigation into both dev manuals for the CPUs.
> >
> > steve ariaza
> >
> >
> >

Dean
Mon Jun 16 07:48:30 PDT 2008

This sounds very hardware specific, and we have even less information than
you. I wouldn't expect much help on this one, sorry...

--
Dean Ramsier - eMVP
BSQUARE Corporation


"Rameshchandra" <Rameshchandra@discussions.microsoft.com> wrote in message
news:BD3FD73B-5366-4A9C-A77B-E9C025069AB2@microsoft.com...
> No one else here have time to have a look at this problem??????
> --
> Ramesh.c
> Innovate Sofware Solutions.
> Bangalore.
>
>
> "Rameshchandra" wrote:
>
>> Yes. I was really fed up with this project. I don't have an document
>> and
>> commands of this spi display.
>>
>> Actually we are simulating the spi interface, though 4 pins, reset,
>> chipselect, clock, data.
>>
>> I am comparing the driver runtime environment on pxa255 with that of the
>> pxa270. For the same spi initialization, the same display connected with
>> pxa270 is working properly, whereas in pxa255 it is behaving as i written
>> in
>> previous post.
>>
>> No improvements on this yet... SPI initialization is lcd specific, is
>> this
>> got anything to do with the processor. Since i am using the same spi
>> initialization commands that was present in pxa270(working commands), in
>> my
>> board pxa255 it should work with out any problems right?
>>
>> I verified my gpio initialization 5 to 6 times... evrything seems to be
>> fine. If my gpio initializations are wrong, when i enable the lcd
>> controller
>> it should not respond right? but in this case it is responding...
>>
>> What is NEC type display??
>>
>> Anone out there to help in this issue??
>>
>> --
>> Ramesh.c
>> Innovate Sofware Solutions.
>> Bangalore.
>>
>>
>> "Steve Araiza" wrote:
>>
>> > Sounds like you are using an NEC display? I am using one with my
>> > PXA270
>> > platform and it was a pain getting the SPI programming of it correct
>> > (very
>> > sparse documentation).
>> >
>> > I would not try to port the PXA270 LCD display driver back to the
>> > PXA255.
>> > There are probably too many differences in the registers and modes.
>> > That's
>> > what sounds wrong with the color bar test, you might be using a
>> > different
>> > color mode than you think.
>> >
>> > You should start with the PXA255 LCD driver, and back port just the SPI
>> > configuration into the LCD driver.
>> >
>> > I have not used the PXA255, but I'm sure there are many differences
>> > between
>> > the LCD registers, and I would not expect the 270 driver to work
>> > without
>> > serious investigation into both dev manuals for the CPUs.
>> >
>> > steve ariaza
>> >
>> >
>> >

Joel
Mon Jun 16 11:07:46 PDT 2008

This is a case when you should be using a logic analyzer to compare
between the working implementation. Suppose you have data idling high
- this could affect your colors.


Joel Winarske
MCTS WinCE 6.0 (957)



On Jun 12, 11:29=A0pm, Rameshchandra
<Rameshchan...@discussions.microsoft.com> wrote:
> Hi all,
>
> I have a pxa270 board with 3.5inch display. =A0It is SAMSUNG LTV350QV_F04.=
=A0I
> have the entire bsp source with me and hence i have the 3.5inch lcd driver=

> for it.
>
> The display uses spi interface to initialize the lcd.
>
> Now, i have a need to interface the same display with my pxa255 processor
> board. So, i am modifying my existing display driver, by referring to my
> pxa270 display driver.
>
> I made the spi initialization part of my display. =A0Now, my display is
> initializing and i can see some changes or happening on my display.
>
> I included a small test program in the display driver which will display t=
he
> color red, green, blue, black and white. =A0Display black, white is ok. =
=A0But
> when i display the color blue, red and green. =A0It is too light. =A0I mea=
n the
> shades are very light. =A0I can't predict what's the reason behind this...=
...
>
> The other problem that i am facing is, after the board boots and display
> driver is up, i could see only some light colored stripes on my lcd. =A0Si=
nce
> the display is having touchscreen builtin. =A0When i touch the touchscreen=

> randomly, i could see that the applications are starting in mydebug window=
s,
> but on the display side, just the strips moves here and there and some col=
or
> changes.
>
> I copied the entire lcd settings, i mean the lccr0,lccr1, lccr2 from my
> pxa270 driver. =A0Even the spi initializations are same...
>
> i tried, using the same dirtyrectdump algorithms that was present in 270.
>
> I have a working lcd driver on my pxa25 board. =A0But this driver is for
> non-spi lcd. =A0It doesn't require any spi initialization nor to select th=
e lcd
> chipselect etc...
>
> The one more difference i am finding between this pxa255 and pxa270 is the=

> alternate function pins L_vsync and L_cs which i can not find in pxa255.
>
> In pxa270 lcd driver they configure L_vsync as input and L_cs as high acti=
ve
> output...
>
> I have not found how to handle these in pxa255 for this lcd....I don't get=

> an clear idea on this stuff.
>
> What may be the problem??? Since i am a new person to display driver. =A0H=
ope
> someone gives me a good idea on what's happening...
>
> If anyother details you are required to help me, i can provide...
>
> expecting suggestions from you experts soon....
>
> --
> Ramesh.c
> Innovate Sofware Solutions.
> Bangalore.

Bradley
Mon Jun 16 11:09:58 PDT 2008

On Jun 16, 2:04 am, Rameshchandra
<Rameshchan...@discussions.microsoft.com> wrote:
> No one else here have time to have a look at this problem?

Have you tried verifying the LCD settings using a scope? You can
measure the Pixel Clock, Vsync, Hsync with a scope on the working
platform running the PXA270 and do the same thing on the platform that
is running the PXA255. If you see the same result on the scope
between the two platforms then you know that you have the LCD
Controller (at least for the timings) correct.

What you can then do is you can write an application that runs in full
screen mode changing the color (as if its 32-bits.) you can again look
at the LCD signals to make sure that you are running it at the correct
color depth (i.e. to ensure that at least all of the LCD RGB signals
are toggling.)

Lastly you can also do the same with the SPI signals between the board
(look at it on PXA270 and compare it to the PXA255.)

Likely, if you do all of the steps below you will find a difference
somewhere that will hopefully lead you in the right direction (at
least in where to look.)

Hope this helps,
Brad.

Rameshchandra
Mon Jun 16 21:31:02 PDT 2008

Hi all,

Great thanks for all of your replies. You gave me some idea on how to debug
the problem. I will proceed in that direction and i will post here if
something happens.
--
Ramesh.c
Innovate Software Solutions.
Bangalore.

Rameshchandra
Wed Jun 18 23:58:00 PDT 2008

Hi all,


It is all ended with an handware problem..... A problem with the boards
design....

Hardware department is taking care of it.
--
Ramesh.c
Innovate Sofware Solutions.
Bangalore.


"Joel Winarske" wrote:

> This is a case when you should be using a logic analyzer to compare
> between the working implementation. Suppose you have data idling high
> - this could affect your colors.
>
>
> Joel Winarske
> MCTS WinCE 6.0 (957)
>
>
>
> On Jun 12, 11:29 pm, Rameshchandra
> <Rameshchan...@discussions.microsoft.com> wrote:
> > Hi all,
> >
> > I have a pxa270 board with 3.5inch display. It is SAMSUNG LTV350QV_F04. I
> > have the entire bsp source with me and hence i have the 3.5inch lcd driver
> > for it.
> >
> > The display uses spi interface to initialize the lcd.
> >
> > Now, i have a need to interface the same display with my pxa255 processor
> > board. So, i am modifying my existing display driver, by referring to my
> > pxa270 display driver.
> >
> > I made the spi initialization part of my display. Now, my display is
> > initializing and i can see some changes or happening on my display.
> >
> > I included a small test program in the display driver which will display the
> > color red, green, blue, black and white. Display black, white is ok. But
> > when i display the color blue, red and green. It is too light. I mean the
> > shades are very light. I can't predict what's the reason behind this.......
> >
> > The other problem that i am facing is, after the board boots and display
> > driver is up, i could see only some light colored stripes on my lcd. Since
> > the display is having touchscreen builtin. When i touch the touchscreen
> > randomly, i could see that the applications are starting in mydebug windows,
> > but on the display side, just the strips moves here and there and some color
> > changes.
> >
> > I copied the entire lcd settings, i mean the lccr0,lccr1, lccr2 from my
> > pxa270 driver. Even the spi initializations are same...
> >
> > i tried, using the same dirtyrectdump algorithms that was present in 270.
> >
> > I have a working lcd driver on my pxa25 board. But this driver is for
> > non-spi lcd. It doesn't require any spi initialization nor to select the lcd
> > chipselect etc...
> >
> > The one more difference i am finding between this pxa255 and pxa270 is the
> > alternate function pins L_vsync and L_cs which i can not find in pxa255.
> >
> > In pxa270 lcd driver they configure L_vsync as input and L_cs as high active
> > output...
> >
> > I have not found how to handle these in pxa255 for this lcd....I don't get
> > an clear idea on this stuff.
> >
> > What may be the problem??? Since i am a new person to display driver. Hope
> > someone gives me a good idea on what's happening...
> >
> > If anyother details you are required to help me, i can provide...
> >
> > expecting suggestions from you experts soon....
> >
> > --
> > Ramesh.c
> > Innovate Sofware Solutions.
> > Bangalore.
>
>