Blue line at the bottom of Mbile LCD

28 Mar 2010

Hi, I'm working on a project using the olimex mobile LCD shown below.

As you can see the display is working quite well, however i don't appear to

be able to address the bottom row of pixels, sorry the picture doesn't illustrate this

very well but believe me there's def a dark blue line across the bottom of the screen.

Can anyone advise me why this is and if anything can be done about it please.

I'm using the library at http://mbed.org/projects/cookbook/svn/MobileLCD/tests/MobileLCD

but have imported the files so i can fiddle with text colours etc.

Any advice would be greatly appreciated.

 

Thanks simon

29 Mar 2010

Hi Simon!

I could tell you why this is, this is because the LCD has 130x130 pixels and the API is addressing only 128x128. I don't really know how to cure this problem (I have exactly the same issue).

Regards,

Devesh

29 Mar 2010

Hi Devesh,

I'm new to C language as until now have written in assembly with PICs, but i've had a look in the MobileLCD.cpp and in the function MobileLCD::MobileLCD (line 165) height and width are defined as 130 but i believe the screen addresses run from 0-131 in both x and y axis, so perhaps these values should be changed to 132?

This pdf http://www.sparkfun.com/tutorial/Nokia%206100%20LCD%20Display%20Driver.pdf gives some detail on the subject of display addressing. Don't be concerned that its titled 6100 LCD driver as the actual driver chips are common between the two types of display, at least i think they are!!

I'm at work and haven't got access to my mbed at the moment but am going to try this out tonight.

regards

Simon

29 Mar 2010

By the way i should credit James grant for the link to that pdf, on this thread

http://mbed.org/forum/mbed/topic/431/?page=1#comment-2229

He also references a tutorial where someone uses a pic to drive the LCD but theres some useful info on the display, this can be found at

http://www.reifel.org/PICUserInterface/

regards

simon