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Interfacing SHARP LM7M632 display

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OneOfProgrammers

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Hello,

I need a 6,5 inch LCD screen (8:3 aspect ratio) to one of my projects. The only one I’ve found in stock is display used in devices like HP Jornada handhelds - SHARP LM7M632 (maybe someone knows other display sized like this with higher resolution and simpler protocol like SPI?). It uses a little bit outdated technology called CSTN. This is the protocol description from datasheet (if you are interested, I am attaching full datasheet that I've received on SHARP’s contact form):

https://i68.tinypic.com/2ik2v40.jpg
2ik2v40.jpg

https://i68.tinypic.com/2vis4s1.png
2vis4s1.png

https://i63.tinypic.com/mrzmzl.png
mrzmzl.png

https://i66.tinypic.com/23uu8lg.png
23uu8lg.png

https://i64.tinypic.com/r25oht.png
r25oht.png


I am planning to use RPi’s native DPI (Display Parallel Interface), which will drive whole data bus (i can set color data order in config.txt as required by the display) and also LP with XCK signals (in DPI they are marked as HSYNC and VSYNC). The M signal (“frame parity” - when sending first frame it should be up, when sending the second one - down, at third - up etc.) will be driven by as small as possible CPLD - programming it (as counting VSYNC and HSYNC signals) should be trivial (few lines of VHDL or Verilog). Also the YD signal will be driven by the CPLD - it should be driven together with LP signal but with a little delay specified in datasheet - it means “display the latched signal”. After that signal the display is ready to receive the second row.

Is my understanding correct? Do anybody know any ready-to-use converter from HDMI/DVI or DPI to this interface (it is called by Chinese sellers “8-bit parallel interface”)? This will eliminate need to program a CPLD.

Cheers,
Simon

Link to the full datasheet: https://drive.google.com/file/d/0B6Bbhtwy8ahiM3RLbWluaUdZRDQ/view?usp=sharing
 
Last edited:

Hi!
I'm surprised to see anyone else trying to do this, I'm also trying to figure out how to interface with one of these things.
Thanks a TON for the datasheet!

If you're still working on this, I'll let you know if I figure anything out.

And if I do end up having to mess with a CPLD I'll send the relevant stuff your way
 

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