LCD without variable resistor

Hi guys, i'm beginner; i want to know if it possible to connect an LCD without variable resistor and if it :drooling_face:
please help me.

The variable resistor you mention is really a potentiometer which functions as an adjustable ‘voltage divider’ to provide the required level at pin 3.

For most displays this required level is around 0.5 volts but some displays work acceptably with 0v. This means that you can start by connecting pin 3 to GND and see what happens.

Otherwise you will need two fixed resistors, a small one (around 1K) between pin 3 and GND and a larger one (around 10K) between pin 3 and Vcc.


I have experience with approx. 15 LCD displays of 4 or 5 different types. For some of the displays I've used, I've gotten legible results with just a 1K resistor from the contrast pin to ground. I have even had a couple of displays work with the contrast pin floating. On the two LCDs I've tried tonight, however, the text can not be distinguished from the background without the 1K resistor.

Using the variable resistor is the recommended approach and gives you the capability to adjust your display for optimal readability. What is your concern with using a variable resistor? Every electronic experimenter's parts bin should have a selection of potentiometers.

If you're just experimenting and don't want to have to go out and buy a new component, you could make a simple voltage divider to set a fixed contrast level. I'd take a relatively large value resistor (say 10K ohm) from V+ to the contrast pin and a smaller resistor (1K ohm) from the contrast pin to ground. Your mileage may vary.

No, I didn't peek at Don's answer.

thank you very much for help..guys.