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Author Topic: LCD contrats variable resistor issue  (Read 808 times)
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Belgium
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Hello,

I am an arduino beginners ... first starter kit received end of last week.

I'v try to use an 16x2 LCD display.

I did connect a variable resistor to adjust the contrats but when I get a correct contrasted screen, I see some smoke from the resistor ... smiley-eek-blue

It looks like a shortcircuit ? When the resistor is near to 0k ??? I don't understand.
I did try with a 5k var resistor and a 2,2k resistor in serial between 5V and 1 of the 3 pins of the var resistor ... It does not work  smiley-confuse smiley-confuse smiley-confuse

Can someone help me please ?
Thx
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Did you connect one end of the resistor to gnd, the other end to 5V and the wiper (the one in the middle usually) to the input for the LCD?
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Except for his use of the term 'resistor' the description for the connections given by marco_c is usually correct since most datasheets call for the use of a potentiometer (a three terminal device) and not a variable resistor (a two terminal device) to control the contrast voltage.

If you were indeed using a potentiometer then you probably had the wiper connected to one of the power supply terminals and, as you adjusted the potentiometer you ultimately got a very low resistance across the power supply terminals, hence the smoke.


Don







« Last Edit: January 27, 2013, 11:04:28 pm by floresta » Logged

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My bad on the name. Of course it is a pot.
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Hello

thanks for the quick answers.

My fault ... bad connection on the breadboard ...

And yes it was a potentiomètre.

my apologize smiley-kiss
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