Hello,
I am trying to use and 480x272 24BPP TFT with the LPC2478 LCD DEMO code from
Olimex kit and is happening something very strange, is not appearing some
part of the image, the original image is 480x272 and is appearing 480x160,
this two images has the same number of pixels. can someone help me?
thanks
LPC2478 and 480x272 24BPP
Started by ●January 27, 2010
Reply by ●January 27, 20102010-01-27
On Wed, 27 Jan 2010 18:59:37 -0200, you wrote:
>Hello,
>
>I am trying to use and 480x272 24BPP TFT with the LPC2478 LCD DEMO code from
>Olimex kit and is happening something very strange, is not appearing some
>part of the image, the original image is 480x272 and is appearing 480x160,
>this two images has the same number of pixels. can someone help me?
>
>thanks
I assume this is the PSP LCD - I have had this working by modifying the IAR olimex board example,
but can't immediately find the code - I don't recall if I was using 16bpp or 24bpp ( NB 24bpp uses
32Bpp in memory)
One thing to note is that the DISP pin on the PSP LCD is NOT a DE line as used on most other LCDs -
it needs to be held high continuously
>Hello,
>
>I am trying to use and 480x272 24BPP TFT with the LPC2478 LCD DEMO code from
>Olimex kit and is happening something very strange, is not appearing some
>part of the image, the original image is 480x272 and is appearing 480x160,
>this two images has the same number of pixels. can someone help me?
>
>thanks
I assume this is the PSP LCD - I have had this working by modifying the IAR olimex board example,
but can't immediately find the code - I don't recall if I was using 16bpp or 24bpp ( NB 24bpp uses
32Bpp in memory)
One thing to note is that the DISP pin on the PSP LCD is NOT a DE line as used on most other LCDs -
it needs to be held high continuously
Reply by ●January 27, 20102010-01-27
is not the PSP LCD, this one is from Winstar company.
The LCD is working, the problem is that the image is missing a part, the
image is 480x272 and is appearing just 480x160, very strange...
I had some trouble to use the olimex code for the same reason as you, it
dindnt work until I turn off the DE pin. In your case, didi you made
something more than just change the the number of pixels in the LCD driver?
Didi you had to change something in the AHB or DMA functions?
2010/1/27 Mike Harrison
> On Wed, 27 Jan 2010 18:59:37 -0200, you wrote:
>
> >Hello,
> >
> >I am trying to use and 480x272 24BPP TFT with the LPC2478 LCD DEMO code
> from
> >Olimex kit and is happening something very strange, is not appearing some
> >part of the image, the original image is 480x272 and is appearing 480x160,
> >this two images has the same number of pixels. can someone help me?
> >
> >thanks
>
> I assume this is the PSP LCD - I have had this working by modifying the IAR
> olimex board example,
> but can't immediately find the code - I don't recall if I was using 16bpp
> or 24bpp ( NB 24bpp uses
> 32Bpp in memory)
>
> One thing to note is that the DISP pin on the PSP LCD is NOT a DE line as
> used on most other LCDs -
> it needs to be held high continuously
>
>
>
The LCD is working, the problem is that the image is missing a part, the
image is 480x272 and is appearing just 480x160, very strange...
I had some trouble to use the olimex code for the same reason as you, it
dindnt work until I turn off the DE pin. In your case, didi you made
something more than just change the the number of pixels in the LCD driver?
Didi you had to change something in the AHB or DMA functions?
2010/1/27 Mike Harrison
> On Wed, 27 Jan 2010 18:59:37 -0200, you wrote:
>
> >Hello,
> >
> >I am trying to use and 480x272 24BPP TFT with the LPC2478 LCD DEMO code
> from
> >Olimex kit and is happening something very strange, is not appearing some
> >part of the image, the original image is 480x272 and is appearing 480x160,
> >this two images has the same number of pixels. can someone help me?
> >
> >thanks
>
> I assume this is the PSP LCD - I have had this working by modifying the IAR
> olimex board example,
> but can't immediately find the code - I don't recall if I was using 16bpp
> or 24bpp ( NB 24bpp uses
> 32Bpp in memory)
>
> One thing to note is that the DISP pin on the PSP LCD is NOT a DE line as
> used on most other LCDs -
> it needs to be held high continuously
>
>
>
Reply by ●January 27, 20102010-01-27
On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>is not the PSP LCD, this one is from Winstar company.
>
>The LCD is working, the problem is that the image is missing a part, the
>image is 480x272 and is appearing just 480x160, very strange...
>
>I had some trouble to use the olimex code for the same reason as you, it
>dindnt work until I turn off the DE pin. In your case, didi you made
>something more than just change the the number of pixels in the LCD driver?
>Didi you had to change something in the AHB or DMA functions?
Sorry I can't remember. Bear in mind that if your memory bus is only 16 bits wide you may run into
bandwidth issues at higher colour depths.
There is an interrupt flag which you can check to detect DMA underruns.
May be worth checking the pixel data on a scope to see if you are sending data on all lines, in case
it's the LCD not liking the timing.
Pixel clock was 9MHz BTW.
>is not the PSP LCD, this one is from Winstar company.
>
>The LCD is working, the problem is that the image is missing a part, the
>image is 480x272 and is appearing just 480x160, very strange...
>
>I had some trouble to use the olimex code for the same reason as you, it
>dindnt work until I turn off the DE pin. In your case, didi you made
>something more than just change the the number of pixels in the LCD driver?
>Didi you had to change something in the AHB or DMA functions?
Sorry I can't remember. Bear in mind that if your memory bus is only 16 bits wide you may run into
bandwidth issues at higher colour depths.
There is an interrupt flag which you can check to detect DMA underruns.
May be worth checking the pixel data on a scope to see if you are sending data on all lines, in case
it's the LCD not liking the timing.
Pixel clock was 9MHz BTW.
Reply by ●January 27, 20102010-01-27
I tryed a RAM 16b and 32b wide and it is the same thing, I will try to
change the LCD clock, Im using 6.4MHz, maybe is this. I am sorry Mike, but
is it possible to you to send me your code to LCD and RAM memory?
thanks
2010/1/27 Mike Harrison
> On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>
> >is not the PSP LCD, this one is from Winstar company.
> >
> >The LCD is working, the problem is that the image is missing a part, the
> >image is 480x272 and is appearing just 480x160, very strange...
> >
> >I had some trouble to use the olimex code for the same reason as you, it
> >dindnt work until I turn off the DE pin. In your case, didi you made
> >something more than just change the the number of pixels in the LCD
> driver?
> >Didi you had to change something in the AHB or DMA functions?
>
> Sorry I can't remember. Bear in mind that if your memory bus is only 16
> bits wide you may run into
> bandwidth issues at higher colour depths.
> There is an interrupt flag which you can check to detect DMA underruns.
> May be worth checking the pixel data on a scope to see if you are sending
> data on all lines, in case
> it's the LCD not liking the timing.
>
> Pixel clock was 9MHz BTW.
>
>
>
change the LCD clock, Im using 6.4MHz, maybe is this. I am sorry Mike, but
is it possible to you to send me your code to LCD and RAM memory?
thanks
2010/1/27 Mike Harrison
> On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>
> >is not the PSP LCD, this one is from Winstar company.
> >
> >The LCD is working, the problem is that the image is missing a part, the
> >image is 480x272 and is appearing just 480x160, very strange...
> >
> >I had some trouble to use the olimex code for the same reason as you, it
> >dindnt work until I turn off the DE pin. In your case, didi you made
> >something more than just change the the number of pixels in the LCD
> driver?
> >Didi you had to change something in the AHB or DMA functions?
>
> Sorry I can't remember. Bear in mind that if your memory bus is only 16
> bits wide you may run into
> bandwidth issues at higher colour depths.
> There is an interrupt flag which you can check to detect DMA underruns.
> May be worth checking the pixel data on a scope to see if you are sending
> data on all lines, in case
> it's the LCD not liking the timing.
>
> Pixel clock was 9MHz BTW.
>
>
>
Reply by ●January 27, 20102010-01-27
I have done code for 2478 and a 24bpp lcd with the same resolution. I got
this panel on www.displayfuture.com. And I started from the olimex code too.
What could be happening is:
1) The Image somehow didn't fit whole in the memory, since LPC2478 isn't
able to hold a 24bpps 480x272 image in its flash or RAM. Check how are you
storing it.
2) There are ocourring back pourch errors, please, refer to display's manual
and configure the clocks propely. Each display has its own clock
configuration. I mean, in mine display I had to change all the clocks
quantitites to write a line proppely.
If you need further help please concact me.
Cya
Felipe.
2010/1/27 Alberto de Martini
> I tryed a RAM 16b and 32b wide and it is the same thing, I will try to
> change the LCD clock, Im using 6.4MHz, maybe is this. I am sorry Mike, but
> is it possible to you to send me your code to LCD and RAM memory?
>
> thanks
>
> 2010/1/27 Mike Harrison > On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>> >is not the PSP LCD, this one is from Winstar company.
>> >
>> >The LCD is working, the problem is that the image is missing a part, the
>> >image is 480x272 and is appearing just 480x160, very strange...
>> >
>> >I had some trouble to use the olimex code for the same reason as you, it
>> >dindnt work until I turn off the DE pin. In your case, didi you made
>> >something more than just change the the number of pixels in the LCD
>> driver?
>> >Didi you had to change something in the AHB or DMA functions?
>>
>> Sorry I can't remember. Bear in mind that if your memory bus is only 16
>> bits wide you may run into
>> bandwidth issues at higher colour depths.
>> There is an interrupt flag which you can check to detect DMA underruns.
>> May be worth checking the pixel data on a scope to see if you are sending
>> data on all lines, in case
>> it's the LCD not liking the timing.
>>
>> Pixel clock was 9MHz BTW.
>
>
this panel on www.displayfuture.com. And I started from the olimex code too.
What could be happening is:
1) The Image somehow didn't fit whole in the memory, since LPC2478 isn't
able to hold a 24bpps 480x272 image in its flash or RAM. Check how are you
storing it.
2) There are ocourring back pourch errors, please, refer to display's manual
and configure the clocks propely. Each display has its own clock
configuration. I mean, in mine display I had to change all the clocks
quantitites to write a line proppely.
If you need further help please concact me.
Cya
Felipe.
2010/1/27 Alberto de Martini
> I tryed a RAM 16b and 32b wide and it is the same thing, I will try to
> change the LCD clock, Im using 6.4MHz, maybe is this. I am sorry Mike, but
> is it possible to you to send me your code to LCD and RAM memory?
>
> thanks
>
> 2010/1/27 Mike Harrison > On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>> >is not the PSP LCD, this one is from Winstar company.
>> >
>> >The LCD is working, the problem is that the image is missing a part, the
>> >image is 480x272 and is appearing just 480x160, very strange...
>> >
>> >I had some trouble to use the olimex code for the same reason as you, it
>> >dindnt work until I turn off the DE pin. In your case, didi you made
>> >something more than just change the the number of pixels in the LCD
>> driver?
>> >Didi you had to change something in the AHB or DMA functions?
>>
>> Sorry I can't remember. Bear in mind that if your memory bus is only 16
>> bits wide you may run into
>> bandwidth issues at higher colour depths.
>> There is an interrupt flag which you can check to detect DMA underruns.
>> May be worth checking the pixel data on a scope to see if you are sending
>> data on all lines, in case
>> it's the LCD not liking the timing.
>>
>> Pixel clock was 9MHz BTW.
>
>
Reply by ●January 28, 20102010-01-28
Hi,
this is definitely not a bandwidth issue, these show up as flickering
when you write something into the framebuffer e.g. via DMA or memcpy()
I'm rather sure about that it's a setting issue - check all the
back/front porch settings, VSYNC/HSYNC polarity and clock length, etc.
If you have one of the parameters setup in the wrong way, very strange
results (e.g. showing half screens only) can occur.
Much luck
Herbert
Mike Harrison schrieb:
> On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>
>
>> is not the PSP LCD, this one is from Winstar company.
>>
>> The LCD is working, the problem is that the image is missing a part, the
>> image is 480x272 and is appearing just 480x160, very strange...
>>
>> I had some trouble to use the olimex code for the same reason as you, it
>> dindnt work until I turn off the DE pin. In your case, didi you made
>> something more than just change the the number of pixels in the LCD driver?
>> Didi you had to change something in the AHB or DMA functions?
>>
>
> Sorry I can't remember. Bear in mind that if your memory bus is only 16 bits wide you may run into
> bandwidth issues at higher colour depths.
> There is an interrupt flag which you can check to detect DMA underruns.
> May be worth checking the pixel data on a scope to see if you are sending data on all lines, in case
> it's the LCD not liking the timing.
>
> Pixel clock was 9MHz BTW.
>
--
demmel products
Radnitzkygasse 43
A-1100 Vienna / Austria / Europe
Voice: +43-1-6894700-0
Fax: +43-1-6894700-40
Email: d...@demmel.com
WWW: http://www.demmel.com
--
demmel products
Radnitzkygasse 43
A-1100 Vienna / Austria / Europe
Voice: +43-1-6894700-0
Fax: +43-1-6894700-40
Email: d...@demmel.com
WWW: http://www.demmel.com
this is definitely not a bandwidth issue, these show up as flickering
when you write something into the framebuffer e.g. via DMA or memcpy()
I'm rather sure about that it's a setting issue - check all the
back/front porch settings, VSYNC/HSYNC polarity and clock length, etc.
If you have one of the parameters setup in the wrong way, very strange
results (e.g. showing half screens only) can occur.
Much luck
Herbert
Mike Harrison schrieb:
> On Wed, 27 Jan 2010 21:03:25 -0200, you wrote:
>
>
>> is not the PSP LCD, this one is from Winstar company.
>>
>> The LCD is working, the problem is that the image is missing a part, the
>> image is 480x272 and is appearing just 480x160, very strange...
>>
>> I had some trouble to use the olimex code for the same reason as you, it
>> dindnt work until I turn off the DE pin. In your case, didi you made
>> something more than just change the the number of pixels in the LCD driver?
>> Didi you had to change something in the AHB or DMA functions?
>>
>
> Sorry I can't remember. Bear in mind that if your memory bus is only 16 bits wide you may run into
> bandwidth issues at higher colour depths.
> There is an interrupt flag which you can check to detect DMA underruns.
> May be worth checking the pixel data on a scope to see if you are sending data on all lines, in case
> it's the LCD not liking the timing.
>
> Pixel clock was 9MHz BTW.
>
--
demmel products
Radnitzkygasse 43
A-1100 Vienna / Austria / Europe
Voice: +43-1-6894700-0
Fax: +43-1-6894700-40
Email: d...@demmel.com
WWW: http://www.demmel.com
--
demmel products
Radnitzkygasse 43
A-1100 Vienna / Austria / Europe
Voice: +43-1-6894700-0
Fax: +43-1-6894700-40
Email: d...@demmel.com
WWW: http://www.demmel.com
