Connecting contrast for Displaytech 64128COG

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Francis
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Connecting contrast for Displaytech 64128COG

Post by Francis » Sat Mar 07, 2009 2:33 pm

I've just obtained a Displaytech 64128COG series from RS Components (part number 532-7114) so I can try out Mark's driver code posted in the Wiki.

I have studied the GLCD data sheet to see the schematic for the caps to produce the LCD drive voltage.

But I just cannot see how/where you connect a pot to adjust the contrast.
has anyone manged to put a knob on their COG GLCD?

Would it be simply a pot configured as a 'rheostat' between the cap and Vout?

Doj
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Post by Doj » Sun Mar 08, 2009 12:39 am

Hello Francis,
I do not recall having a pot on the display at all, I am going in to my office tomorrow so I will find my original test board.
If I read the data sheet correctly I see it has an electronic alteration of the contrast in 64 steps.

Francis
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Post by Francis » Sun Mar 08, 2009 11:12 am

Oh, thanks.
I'd better polish my glasses and have another look.

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