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lcd signals.........

stranger

Jun 18, 2010
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Jun 18, 2010
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im working on decoding lcd signals.........where i read in the signals into a micro and find the digit the lcd display shows..........


I just wanted to know whether the signals are like..........one type of continuous signal for a one digit(like a different signal for 1 and 2) or if the signal is time dependent to produce a digit(like same signals for 1 and 2 but for different time intervals)......


thanks in advance
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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LCD panels typically place an AC voltage across each segment or pixel. You'll find that the backplane has a square wave signal imposed on it. The segments that are off have the same signal, and the ones that are on have it inverted.

So, you'll see pretty much exactly the same signal (wrt gnd) on segments that are on or off. You need to compare the signal to the backplane and probably deglitch it.
 

Resqueline

Jul 31, 2009
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And to add to the complexity; many small LCD's have the backplane divided into two, one for four of the segments and one for three of the segments + decimal points..
 
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