LCD Arduino Tutorial – How to connect LCD with Arduino

#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int i=0;
void setup() {
  lcd.begin(16, 2);
}

void loop() {
  lcd.setCursor(4,0);
  lcd.print("Mechatrofice");
  for(i=0;i<4;i++){
    lcd.scrollDisplayLeft();
    delay(500);
  }
   for(i=0;i<4;i++){
  lcd.scrollDisplayRight();
   delay(500);
}}

Try the above sample code which moves the text “Mechatrofice” to and fro on the 16×2 LCD display.

LCD to Arduino interface using I2C/IIC Adapter

Another easy method to interface an LCD display with Arduino is by using an I2C serial interface adapter module.

The advantage of the LCD I2C interface is it keeps the circuit neat and simple and it is less complex in connection. For bigger circuits, this is the most feasible method because a smaller number of Arduino pins will be reserved for the LCD display.

In the above method, the LCD is connected directly to Arduino through a parallel connection. By using an I2C interface, parallel communication is converted to serial I2C communication. I2C is a serial protocol with a two-wire interface method using communication lines SDA (Serial DATA Line) and SCL (Serial Clock Line). So including two wires for VCC & GND, the connection to LCD from the Arduino can be limited to a 4-wire circuit.

In the parallel LCD interface, the library used was LiquidCrystal.h. But for an I2C interface, LiquidCrystal_I2C.h and wire.h libraries are required; wire.h library is for I2C communication and the LCD library allows the Arduino board to control Liquid Crystal displays.

The Wire.h library is already inbuilt in Arduino IDE that allows us to communicate with I2C/ TWI (Inter-Integrated Circuit /Two Wire Interface) devices. To add the LiquidCrystal I2C library either download.zip file or add directly from the library manager.

Download Library

https://github.com/fdebrabander/Arduino-LiquidCrystal-I2C-library, or
https://github.com/johnrickman/LiquidCrystal_I2C – In this library, wire.h is already included in the LiquidCrystal_I2C Library, it doesn’t need wire.h to imported additional in the sketch. The below code has an inbuilt wire library with the LCD library so the #include <wire.h> is commented in the code(//#include <wire.h> ), just include wire.h if the LCD library requires it.

In Arduino IDE, Sketch > Include Library > Add .ZIP Library > Select and open the downloaded zip file. The Arduino sketch given on this page is suitable to work with the above two libraries.

Install from the library manager

Sketch > Include Library > Manage libraries > search for LiquidCrystal_I2C and install the library.

Connect the LCD and I2C adapter as in the circuit or directly plug the 16 male header pins of the I2C module to the LCD female header pins, then the serial pins of the I2C adapter can be connected to the Arduino. The contrast of the LCD can be adjusted by the potentiometer on the I2C module.

I2C to Arduino connection

Arduino LCD code using I2C

#include <LiquidCrystal_I2C.h>
//#include <wire.h>
//I2C address 0x27
LiquidCrystal_I2C lcd(0x27,16,2); //16x2 display
void setup()
{
  lcd.init();// initialize the lcd 
  lcd.backlight();// Backlight ON
  lcd.setCursor(1,0);// 2nd column,1st row
  lcd.print("Hello, world!");
  lcd.setCursor(0,1);// 1st column,2nd row
  lcd.print("Arduino I2C/IIC");
  delay(3000);
}

void loop()
{
  lcd.clear();
  delay(500);
  lcd.setCursor(0,0);
  lcd.print("_");
  delay(500);
}