How to interface a 16x2 LCD with Arduino without a potentiometer?

Yes, you can still control the contrast of a 16x2 LCD without a 10k potentiometer. There are two ways to do it.

Use Fixed Resistors

You can create a voltage divider using two resistors. A common configuration is:

• Connect a 1kΩ resistor from V0 (pin 3) to GND

• Connect a 10kΩ resistor from V0 to VCC (5V)

This should give you a decent contrast level, although it's not adjustable. You can experiment with different resistor values to tweak the contrast.

Use PWM (Software-Controlled Contrast)

You can connect V0 to a PWM-capable pin on the Arduino (like D9 or D10), and then use

analogWrite()

to adjust the contrast in software

analogWrite(9, 50); // Adjust the value (0–255) to set contrast

Add a low-pass filter (typically a 10k resistor and a 0.1µF capacitor) between the PWM pin and V0 to smooth out the signal into a more stable DC voltage.

Notes:

• Avoid connecting V0 directly to GND or 5V, as the display will either be completely blank or fully dark.

• The PWM method gives you flexibility, but might introduce flicker if not filtered properly.

So yes, a potentiometer makes things easier, but there are reliable workarounds!

Hope this helps!