[PIC] value of POT-meter to be used

[KhaledOsmani]

hello

what potentiometer value should I use with 2*16 LCD interfaced with pic microcontroller?

is it 1k or 4,7kohm?

 

[paulfjujo]

pot to adjust the contrast ?
4.7K or 10K

 

[Gorgon]

If you talk about contrast pot-meter it's normally in the 20k range.

Depends a bit on the contrast voltage, but 10-20k will be ok.

 

[KhaledOsmani]

Anode is directly connected to -5V
Cathode is directly connected to +5V right ?

 

[paulfjujo]

hello,


what is the relation ship with the POT ?

post un shematic to comment your question ...
Anode cathode of backlight led ?

 

[betwixt]

If you are talking about anode and cathode, do you mean the backlight LED or the contrast control?

The current through the contrast pin (VEE) is very small so you can use any value up to about 20K, wired between ground and +5V. Some will allow you to wire to negative voltages but check the data sheet first, if yours doesn't and you wire to a negative voltage it will destroy the LCD controller.

If you are talking about the backlight LED (which has anode and cathode pins on most LCD modules) I do not recommend you use a potentiometer at all. The current can be quite high and power dissipation through a pot may overheat it. It would be better to use a fixed resistor of sufficient power rating.

Brian.