Got my LCD from sparkfun the other day and it is a 16X2. Want to upload the LiquidCrystal "Hello World!" display program but without the potentiometer. What would be the code and the pin configuration ? Sorry to say but I am a complete noob to this. Please help..
You need the potentiometer to adjust the backlight to right level so.... Otherwise you don't see anything
the other solution is to send a PWM signal to mimic the potentiometer. it needs also to be on the right values, so make a loop going though all the pwm values with a small delay and print the value on the LCD, when you see the value on the LCD then you have the right intensity.
I have done that once when I ran out of Pots 
It did work ok, small flicker but ok (but then I did use a shiftregister also )
D.
Want to upload the LiquidCrystal "Hello World!" display program
Describes the pin configuration...
but without the potentiometer.
Might as well just take a hammer to the LCD now...
The potentiometer is to adjust the contrast. It is not optional.
Gotcha..!
I think the LCD screens are rated to 7v and your only putting in 5v so there is little chance of cooking it.
But the potentiometer could be replaced by a plane old resistor, try a 1k ohm if there is no text try a smaller one.
@Hellonearthis
But the potentiometer could be replaced by a plane old resistor, try a 1k ohm if there is no text try a smaller one.
You are meaning resistor divider right??.. don't think you would get the right effect otherwise
The LCD Pin 3 VO Contrast - I connect it via a resistor to ground.
Am I doing something bad?
The pot is only the job of a resistor isn't it?
The LCD Pin 3 VO Contrast - I connect it via a resistor to ground.
Am I doing something bad?
Most LCD modules require a small positive voltage at pin 3. A correctly connected potentiometer is acting like a voltage divider to provide this voltage.
Many LCD modules work acceptably with 0 volts at pin 3. In this case you can ground pin 3 or pull it low with a resistor which is essentially what you are doing.
The pot is only the job of a resistor isn't it?
A rheostat is a variable resistor with two terminals. In a circuit that requires a rheostat you could substitute a resistor if you happen to have one that is the correct value.
A potentiometer is a variable resistor with three terminals. In a circuit that requires a potentiometer (such as this one) you could substitute two resistors if you had two that are the correct values.
Don