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I have pulled a 240x320 LCD screen out of a Nokia 6500s, and am interested in interfacing with it. Some people have worked with it, including posting PIC source code and schematics for the board they build to interface with it. The board-to-board connector is 24-pin 0.4 mm pitch, and apparently the driver also wants < 1.95 V logic, so I have essentially copied the schematic at http://gobotronics.wordpress.com/2010/09/12/time-to-post-some-details/ and have digested details at http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=auto&tl=en&u=http%3A%2F%2Fwww.elektroda.pl%2Frtvforum%2Fviewtopic.php%3Ft%3D1344700%26sid%3De2fac4ea42d6c7df3d88a62263350eea&act=url. My schematic is below. IC1 and IC2 are 74LVC4245A logic level converters.

 

The schematics in the links above both link VLED1- to VLED2+ and supply 12 V across the lot. I would like my end result to be as standalone-friendly as possible, so have linked the two LED sets in parallel with 6 V across. Essentially, my questions are general ones about implementation and feasibility. I'm aware that I won't be able to drive the display at a high frame rate with an ATmega328, I'm just interested in having it work at all.

Does anyone with more general experience have any comments or suggestions on how to go about this - do you think the approach that I'm taking (and have copied from others!) sounds reasonable?

[Aside: I posted a version of this question in the previous forum at http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1295188814/3, but didn't really ask all the questions I wanted to ask.]

[Reply #1 on:]

I have a quick question: all the other schematics for this display (including the schematic for the phone that the display came out of), link VLED1- to VLED2+, with VLED2- connected to ground and VLED1+ connected to 12 V. Each of VLED1 and VLED2 runs to a pair of LEDs in series (for the backlight). I know this is a very basic question (unfortunately, I'm much more at home with writing the library for this than with the hardware), but am I correct in thinking that I can run them in parallel with 6 V across the pair? Is that a bad idea i.e., it could lead to uneven backlighting (as far as I understand it, due to my not being able to guarantee equal flow of current through the two "branches")? Additionally, if it were not a bad idea, what kind of value would be required for the current limiting resistor (or resistors - do I need one on each "branch" of the parallel circuit)?

Thanks!

[Reply #2 on:]

Hi, i have such a celphone to dismount, but before doing it i would like to know if you or someone else could make it work with arduino, or not.

thanks, Davide.