Published May 30, 2022 © GPL3+

Lcd Without Potentiometer

Shows how to use an lcd without a potentiomer!

IntermediateProtip2,736

Things used in this project

Hardware components

Alphanumeric LCD, 16 x 2

Arduino UNO

Any other will work too!

Jumper wires (generic)

Resistor 220 ohm

Software apps and online services

Arduino IDE

Story

Once I needed to make a project with an lcd, but I only had one potentiometer that I needed it elsewhere. So, I googled some things about potentiometers and how they work and came up with this!

How a potentiometer works?

A potentiometer is like a resistor that you can change values of. It works pretty simple.

It's just a "wire"(resistive strip) that makes the current flow through it from ground to vcc. While the current flows through, the wiper touches the resistive strip in different places and the current that flows through the strip goes to the wiper and depending on the place, different current comes out from the output.

So what?

So, a potentiometer is just a metal wire that has different current flowing through it. So, by varying the current that flows through the resistive strip we can make our own potentiometer without a wiper!

1 / 2 • We vary the purple wire and the output is different.

const int contrast = 13;
void setup() {
 analogWrite(contrast, 130);

By the process of try I figured that contrast 130 works the best.

Conclusion

Congratulations!

You have just made a "potentiometer" by yourself.

You can also make an lcd without a resistor using the same method of analogWrite() function. But I havn't tried that yet.

Code

Lcd without potentiometer

#include <LiquidCrystal.h> //Import the LCD library
//Include^
//Init
LiquidCrystal lcd(12, 11, 5, 4, 3, 2); /*Initialize the LCD and
                                        tell it which pins is
                                        to be used for communicating*/


const int contrast = 13;

void setup() {
  analogWrite(contrast, 130);
  // put your setup code here, to run once:
  lcd.begin(16, 2); //Tell the LCD that it is a 16x2 LCD
  //pinMode-ing OUTPUT makes the specified pin output power
}

void loop() {
  // put your main code here, to run repeatedly:
  lcd.print(" Hello, World!!"); //Output " Hello, World!!" on the first line of the LCD
  lcd.setCursor(0, 1); /*Set the (invisible) cursor on the first place second row of the LCD.
                        Cursor values are 0-indexed, 0 would the be the first place.
                        The cursor coordinates are X,Y coordinates.*/
  lcd.print("16x2 LCD Screen");
  delay(1000); //Wait a second
  for (int l = 0; l < 16; l++) { //For loop. Repeating 16 times
    lcd.scrollDisplayRight(); //Scroll whole screen to the right once
    delay(90); //Slight delay for animation
  }
  delay(1000);
  for (int l = 0; l < 16; l++)
    lcd.scrollDisplayLeft();
  for (int l = 51; l > -1; l--) { //Repeating 51 times
    analogWrite(bri, l * 5);
    delay(35);
  }
  delay(1000);
  for (int l = 0; l < 51; l++) { //Repeating 51 times
    analogWrite(contra, l * 5);
    delay(35);
  }
  delay(1000);
  lcd.setCursor(0, 0);
}