Arduino Uno analog pins query.

Can anyone tell me if it is possible to vary the ouput voltage on an Anolog pin of the Uno by means of a software command. I want to control the brightness of an LCD panel instead of using a potentiometer as I do a present.

is possible to vary the ouput voltage on an Anolog pin of the Uno by means of a software command.

No.

I want to control the brightness of an LCD panel

Yes that is perfectly possible, you just use PWM and automatically turn it on and off rapidly and that dims it.

Software PWM can be done on any pin, or hardware PWM on selected pins (3,5,6,9,10,11 on Uno for example).

Thanks Mike and Crossroads for your replies and suggestions. I am fairly new to this mode of operation, can you suggest any available Sketch which demonstrates this procedure and where it can be obtained…?

byte pwmPin3 = 3;
void setup(){
pinMode (pwmPin3, OUTPUT);
}
void loop(){
// read 10-bit result pot connected to A0, send to 8-bit PWM output
analogWrite (pwmPin3, (analogRead(A0)>>2);
}

can you suggest any available Sketch which demonstrates this procedure and where it can be obtained..?

Arduino IDE. File -> Examples -> 03 Analog -> Fading