Using Samsung 800X480 LCD with Palo 43

[gumstixdude]

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude

[gnmckinney]

In looking at the specs and wiring it looks like it may work - of course you will need to change the resolution of the display in the kernel and possibly in the uboot variables (check the forums for how this is done as there is a great deal about it there).

I decided to order one of the displays to see if it will indeed work - I, too, want more resolution than the lcd panel offered by Gumstix and this may be the way to do it - the Palo board has all of the interfacing needed - now to just get the slight differences resolved (the panel you listed has two led strings so power has to be configured for the second string and there is a PWRSEL signal (pin-35) on the Gumstix lcd that is not on the panel you spec'ed out.  Like I said - minor differences.  If the actual connectors match these issues are very trivial indeed (grin).

gm...

gumstixdude wrote:

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude

[gumstixdude]

Aren't they both 45 pin connectors? Hopefully that means they will work. What will need to be done to get the second LED string powered?



In looking at the specs and wiring it looks like it may work - of course you will need to change the resolution of the display in the kernel and possibly in the uboot variables (check the forums for how this is done as there is a great deal about it there).

I decided to order one of the displays to see if it will indeed work - I, too, want more resolution than the lcd panel offered by Gumstix and this may be the way to do it - the Palo board has all of the interfacing needed - now to just get the slight differences resolved (the panel you listed has two led strings so power has to be configured for the second string and there is a PWRSEL signal (pin-35) on the Gumstix lcd that is not on the panel you spec'ed out.  Like I said - minor differences.  If the actual connectors match these issues are very trivial indeed (grin).

gm...

gumstixdude wrote:

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude

[gnmckinney]

Yes - From the spec sheets they are both 45-pin 0.5-mm connectors but carry different part numbers - I have not looked (yet) to see what the actual difference is.

As for the LED backlight circuit - it looks like there are two strings of seven LED's that comprise the backlight system for this LCD display.  I am looking at what (if any) changes would need to be done to power both strings by the current LED circuit on the Palo board.  I think it may be possible to just connect the two strings in series then adjust the feedback resister to increase the current somewhat but until I receive the LCD display I ordered I really can not say what will be needed.  I do know, from the Palo schematics that pin 42 and 43 of the LCD connector are the current LED connections for the Samsung LCD sold by Gumstix - the LCD display mentioned in this thread also uses pins 44 & 45 for the second LCD string and are currently not connected to anything.  To allow a serial connection of the LCD strings I will need to modify the connections on the LCD connector (basically cut the trace to pin 43 and fly-wire it to pin 45 then connection pin 43 and 44 together to connect the two LED strings in series).

I will post results as I go so others may follow (or not) what is done (grin).

In the mean time I am looking at what needs to be changed software/kernel wise to get the display resolution setup correctly for the 800X480 display - any suggestions would be appreciated - I am more hardware oriented than software oriented (more touchy touchy than thinky thinky - grin).

gm...



Aren't they both 45 pin connectors? Hopefully that means they will work. What will need to be done to get the second LED string powered?

gnmckinney wrote:

In looking at the specs and wiring it looks like it may work - of course you will need to change the resolution of the display in the kernel and possibly in the uboot variables (check the forums for how this is done as there is a great deal about it there).

I decided to order one of the displays to see if it will indeed work - I, too, want more resolution than the lcd panel offered by Gumstix and this may be the way to do it - the Palo board has all of the interfacing needed - now to just get the slight differences resolved (the panel you listed has two led strings so power has to be configured for the second string and there is a PWRSEL signal (pin-35) on the Gumstix lcd that is not on the panel you spec'ed out.  Like I said - minor differences.  If the actual connectors match these issues are very trivial indeed (grin).

gm...

gumstixdude wrote:

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude

[gumstixdude]

I bought one of these displays also this afternoon so looks like we're in this together :) I wonder if powering only one of the sets of LED backlights results in only half of the screen being lit or the whole screen being lit at half of the maximum brightness. If it's the latter and you don't need the screen too bright, that would be a convenient way to solve our problem.



Yes - From the spec sheets they are both 45-pin 0.5-mm connectors but carry different part numbers - I have not looked (yet) to see what the actual difference is.

As for the LED backlight circuit - it looks like there are two strings of seven LED's that comprise the backlight system for this LCD display.  I am looking at what (if any) changes would need to be done to power both strings by the current LED circuit on the Palo board.  I think it may be possible to just connect the two strings in series then adjust the feedback resister to increase the current somewhat but until I receive the LCD display I ordered I really can not say what will be needed.  I do know, from the Palo schematics that pin 42 and 43 of the LCD connector are the current LED connections for the Samsung LCD sold by Gumstix - the LCD display mentioned in this thread also uses pins 44 & 45 for the second LCD string and are currently not connected to anything.  To allow a serial connection of the LCD strings I will need to modify the connections on the LCD connector (basically cut the trace to pin 43 and fly-wire it to pin 45 then connection pin 43 and 44 together to connect the two LED strings in series).

I will post results as I go so others may follow (or not) what is done (grin).

In the mean time I am looking at what needs to be changed software/kernel wise to get the display resolution setup correctly for the 800X480 display - any suggestions would be appreciated - I am more hardware oriented than software oriented (more touchy touchy than thinky thinky - grin).

gm...



Aren't they both 45 pin connectors? Hopefully that means they will work. What will need to be done to get the second LED string powered?

gnmckinney wrote:

In looking at the specs and wiring it looks like it may work - of course you will need to change the resolution of the display in the kernel and possibly in the uboot variables (check the forums for how this is done as there is a great deal about it there).

I decided to order one of the displays to see if it will indeed work - I, too, want more resolution than the lcd panel offered by Gumstix and this may be the way to do it - the Palo board has all of the interfacing needed - now to just get the slight differences resolved (the panel you listed has two led strings so power has to be configured for the second string and there is a PWRSEL signal (pin-35) on the Gumstix lcd that is not on the panel you spec'ed out.  Like I said - minor differences.  If the actual connectors match these issues are very trivial indeed (grin).

gm...

gumstixdude wrote:

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude

[gnmckinney]

Well - I received my 800 X 480 LCD display last Wednesday but had to wait until the following day to get it as USPS (United Stated Post Office) needed a signature to deliver it and nobody was home Wednesday.

I did some more research and posted the information on one of my blogs about the display and what is needed to get it working with the Palo-43 LCD interface board (grin)....

http://overoinfo.blogspot.com/

The modifications to get it working are VERY MINIMAL and you end up with a display with about 4X the resolution than offered with the LCD display Gumstix sells.  The price difference is about 15 Dollars (US) counting the postage for shipping!  Not a bad deal at all!

gm...


I bought one of these displays also this afternoon so looks like we're in this together :) I wonder if powering only one of the sets of LED backlights results in only half of the screen being lit or the whole screen being lit at half of the maximum brightness. If it's the latter and you don't need the screen too bright, that would be a convenient way to solve our problem.



Yes - From the spec sheets they are both 45-pin 0.5-mm connectors but carry different part numbers - I have not looked (yet) to see what the actual difference is.

As for the LED backlight circuit - it looks like there are two strings of seven LED's that comprise the backlight system for this LCD display.  I am looking at what (if any) changes would need to be done to power both strings by the current LED circuit on the Palo board.  I think it may be possible to just connect the two strings in series then adjust the feedback resister to increase the current somewhat but until I receive the LCD display I ordered I really can not say what will be needed.  I do know, from the Palo schematics that pin 42 and 43 of the LCD connector are the current LED connections for the Samsung LCD sold by Gumstix - the LCD display mentioned in this thread also uses pins 44 & 45 for the second LCD string and are currently not connected to anything.  To allow a serial connection of the LCD strings I will need to modify the connections on the LCD connector (basically cut the trace to pin 43 and fly-wire it to pin 45 then connection pin 43 and 44 together to connect the two LED strings in series).

I will post results as I go so others may follow (or not) what is done (grin).

In the mean time I am looking at what needs to be changed software/kernel wise to get the display resolution setup correctly for the 800X480 display - any suggestions would be appreciated - I am more hardware oriented than software oriented (more touchy touchy than thinky thinky - grin).

gm...

gumstixdude wrote:

Aren't they both 45 pin connectors? Hopefully that means they will work. What will need to be done to get the second LED string powered?

gnmckinney wrote:

In looking at the specs and wiring it looks like it may work - of course you will need to change the resolution of the display in the kernel and possibly in the uboot variables (check the forums for how this is done as there is a great deal about it there).

I decided to order one of the displays to see if it will indeed work - I, too, want more resolution than the lcd panel offered by Gumstix and this may be the way to do it - the Palo board has all of the interfacing needed - now to just get the slight differences resolved (the panel you listed has two led strings so power has to be configured for the second string and there is a PWRSEL signal (pin-35) on the Gumstix lcd that is not on the panel you spec'ed out.  Like I said - minor differences.  If the actual connectors match these issues are very trivial indeed (grin).

gm...

gumstixdude wrote:

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude

[gumstixdude]

What tools did you use to cut the copper connector? I thought about using an X-acto knife but it doesn't seem like the right tool. Any advice? Also, can you explain a bit more how you cut the copper connector in a bit more detail than you did on your blog?

Thanks,

Gumstixdude

[gnmckinney]

Actually - I did use an X-Acto knife to cut the trace - I used a small blade that comes to a fine point.  I cut the trace just above the actual connector contact.  If you look closely you will see the ground trace (double width) branches to connector pads 35 & 36.  Where the ground branches to connector pad 35 is where I made the cut to break the ground connection to connector pad 35.  I removed about 1-mm or so of copper material to insure good isolation.

That make sense???

gm...

gumstixdude wrote:

What tools did you use to cut the copper connector? I thought about using an X-acto knife but it doesn't seem like the right tool. Any advice? Also, can you explain a bit more how you cut the copper connector in a bit more detail than you did on your blog?

Thanks,

Gumstixdude

[pierre1313]

Hello

Thanks everyone for your valuable contributions. I too just bought this lcd to work with my gumstix system.

my question is that gumstix was out of the Palo43 board and I bought the new chestnut board. Does anyone here has any experience modifying a chestnut board to work with this lcd ?

Bonus question : why cut the copper trace rather than lifting the pin on the connector ?

Thanks a lot

gumstixdude wrote:

Hello,

I want to have a higher resolution display than the one offered by Gumstix. If I try to use a Samsung LCD with touchscreen with a resolution of 800x480, will it work?

Here is the link to the display:

http://cgi.ebay.com/4-8inch-TFT-LCD-Module-800x480-LMS480KF02_W0QQitemZ300309948034QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ebde2682&_trksid=p4634.c0.m14.l1262&_trkparms=%7C293%3A2%7C294%3A30

Thanks,

Gumstixdude