Interfacing 16x2 LCD display with Arduino Nano

Abstract

In this article, you’ll learn a detailed, step-by-step method to interface a 16×2 LCD character display with the Arduino Nano using the Arduino IDE. By the end, you’ll be able to display text on the LCD — a fundamental building block for many microcontroller projects like menus, status readouts, timers, and sensors display.

Pre-Request

• OS : Windows / Linux / Mac / Chrome
• Arduino IDE

Hardware Required

• Arduino Nano.
• 16x2 LCD display.
• Resistors.
• Potentiometer (10 kΩ)
• BreadBoard.
• Mini USB Cable.
• Connecting wires.
• 5V DC power supply (Optional)

Connection Table

16x2 LCD can be connected in 4 wire and 8 wire mode. In this article 4 wire mode is demonstrated, as 8 wire mode is rarely used now a days.

Code

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#include <LiquidCrystal.h>

//  Pin Definitions
# define RS 6
# define E 5
# define D7 1
# define D6 2
# define D5 3
# define D4 4


// Initialize the LCD with the pins:
// LiquidCrystal(rs, en, d4, d5, d6, d7)
LiquidCrystal lcd(RS, E, D4, D5, D6, D7);

void setup() {
    lcd.begin(16, 2);  // Set the LCD size to 16 columns and 2 rows
    lcd.print("Welcome to"); // Print first line
    lcd.setCursor(0, 1);  // Move cursor to second line
    lcd.print("Aavishkarah"); // Print Second line
    delay(3000); // Delay of 3 sec
}

void loop() {
    // Print 0 to 9 with a delay of 1.5 sec for an infinite loop    
    for (int i=0; i<10; i++){
        lcd.clear();
        lcd.print(i);
        delay(1500);
    }
}

Code Explanation

Let’s break down the Arduino sketch line by line to clearly understand how the 16×2 LCD works with the Arduino Nano.

Imports

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#include <LiquidCrystal.h>

• This line includes the LiquidCrystal library.
• It provides ready-to-use functions to control 16×2 LCD displays such as print(), clear(), setCursor() etc.,

Define LCD Pin Connections

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//  Pin Definitions
# define RS 6
# define E 5
# define D7 1
# define D6 2
# define D5 3
# define D4 4

• These #define statements assign Arduino Nano pins to the LCD control and data pins.
• RS (Register Select) chooses between command mode and data mode.
• E (Enable) triggers data transfer.
• D4–D7 are data lines used in 4-bit mode, reducing the number of pins required.

Create the LCD Object

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// Initialize the LCD with the pins:
// LiquidCrystal(rs, en, d4, d5, d6, d7)
LiquidCrystal lcd(RS, E, D4, D5, D6, D7);

• This creates an LCD object named lcd.
• The pin order must be: RS, Enable, D4, D5, D6, D7
• From this point onward, all LCD operations are performed using the lcd object.

Initialize the LCD in setup()

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  lcd.begin(16, 2);

• lcd.begin(16, 2) initializes the LCD with 16 columns and 2 rows.
• This must be called before sending any data to the LCD.

Display Static Text

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  lcd.print("Welcome to");
  lcd.setCursor(0, 1);
  lcd.print("Aavishkarah");
  delay(3000);

• lcd.print("Welcome to") prints text on the first line.
• lcd.setCursor(0, 1) moves the cursor to column 0, row 1 (second line).
• lcd.print("Aavishkarah") displays text on the second line.
• delay(3000) pauses execution for 3 seconds.
• This allows the welcome message to stay visible before moving to the loop section.

Display Numbers 0 to 9 Repeatedly

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  for (int i=0; i<10; i++){
    lcd.clear();
    lcd.print(i);
    delay(1500);
  }

• The loop() function runs continuously after setup() completes.
• The for loop counts from 0 to 9.
• lcd.clear() clears the LCD before printing the next number.
• lcd.print(i) displays the current number.
• delay(1500) holds each number on the display for 1.5 seconds.
• After reaching 9, the loop restarts, creating an infinite display cycle.

Simulation

Extras

Components details

• Arduino Nano Data Sheet
• 16x2 LCD Display Data Sheet

Modules / Libraries Used

• LiquidCrystal.h
  • It provides ready-to-use functions to control 16×2 LCD displays such as print(), clear(), setCursor() etc.,
  • More info
  • Github Source Code