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Topic: Can you "invert" the LCD display? (Read 2 times) previous topic - next topic

lost_and_confused

Usually the display on a LCD is a clear background and the information/letters/numbers are black.

I know if you use a polariser, you can "invert" the display so the background is black and the display is clear.

Yeah, not impossible, but I was wondering if it is possible with programming?

I have the 20x4 display and am using it as a bedside clock.

Though I can turn down the backlighting, I was thinking it would look "nicer" if it was the digits which emitted the light rather than the whole display with the digits being black.


Anyone?

floresta

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Usually the display on a LCD is a clear background and the information/letters/numbers are black.

This is what is known as a 'Positive' LCD.  You are looking for a 'Negative' LCD.

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...but I was wondering if it is possible with programming?

I don't think so.

Don


Grumpy_Mike

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but I was wondering if it is possible with programming?

Only if you have access to each individual pixel in the display which in most cases you don't.

You can get positive and negative displays but you choose when you buy it.

bperrybap

You could kind of sort of do it using custom characters to create a "large" font.
You would need to create the blocks for the larger font but then invert them.
If all you need is digits then the custom chars can be pretty simple.
If you don't already have a character that is "all pixels on" reserve 1 custom character to be all "black".
You would end up with a mostly dark display but there would still be
light around the edges and in between the LCD characters.


There are a few example sketches floating around out there that do large fonts on character LCDs
and here is thread that talks about it:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1245352653

In your case you will want to invert all the bits to allow the light to show through.


--- bill

Graynomad

That will still have a clear background, just with odd-looking reversed characters in 5x8 (or whatever) blocks.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

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