How to make a message, like “Hello”, scroll across the LCD?

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To make a message like “Hello” scroll across an LCD using an I2C module with a 16×2 LCD on an Arduino, you need to follow these steps. Below is the Arduino code and the circuit setup.

Circuit Setup:

  1. Components needed:
    • Arduino Uno (or any compatible board)
    • 16×2 LCD Display with I2C module
    • Jumper wires
    • Breadboard (optional)
  2. Connections:
    • VCC (LCD) to 5V (Arduino)
    • GND (LCD) to GND (Arduino)
    • SDA (LCD) to A4 (Arduino Uno)
    • SCL (LCD) to A5 (Arduino Uno)

Arduino Code:

#include <Wire.h>               // Include the Wire library for I2C communication
#include <LiquidCrystal_I2C.h>   // Include the LiquidCrystal_I2C library

// Initialize the LCD with I2C address 0x27 (or adjust if necessary)
LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16x2 LCD screen

void setup() {
  lcd.begin(16, 2);            // Initialize LCD with 16 columns and 2 rows
  lcd.setBacklight(1);         // Turn on the backlight
  delay(1000);                 // Wait for 1 second
  
  // Print a static message "Hello" for testing
  lcd.setCursor(0, 0);         // Set the cursor to the first row, first column
  lcd.print("Hello");           // Print the "Hello" message
  delay(1000);                  // Wait for 2 seconds before starting the scroll
}

void loop() {
  String message = "Hello ";    // The message to scroll
  int messageLength = message.length();

  // Loop through the positions and scroll the message from right to left
  for (int position = 16; position >= -messageLength; position--) {
    // Clear the first row to remove any previous message
    lcd.setCursor(0, 0);        // Set cursor at position (0, 0)
    lcd.print("                ");  // Print spaces to clear any existing text

    // Set the cursor to the new position and print the message
    lcd.setCursor(position, 0); // Set cursor at current position
    lcd.print(message);         // Print the message
    
    delay(1000);                 // Delay to create the scrolling effect
  }
}

Explanation of the Code:

  1. Library Includes:
    • The Wire.h library is used for I2C communication.
    • The LiquidCrystal_I2C.h library is used to control the LCD via I2C.
  2. LCD Initialization:
    • lcd.begin() initializes the LCD.
    • lcd.backlight() turns on the LCD’s backlight.
  3. Scrolling Mechanism:
    • The message variable holds the text “Hello” which we want to scroll.
    • In the loop(), the message is scrolled from right to left across the screen.
    • The lcd.clear() command clears the screen before printing the next portion of the message.
    • lcd.setCursor(position, 0) moves the cursor to the position from where the message will be printed.
    • lcd.print(message) displays the message at the current cursor position.
    • The delay(300) adds a delay of 300 milliseconds between each scroll.

Final Notes:

  • Make sure to install the LiquidCrystal_I2C library in the Arduino IDE. You can do this by going to Sketch > Include Library > Manage Libraries and then searching for LiquidCrystal_I2C and installing it.
  • The I2C address 0x27 is used in the code, but some LCD modules might have a different address like 0x3F. You can find the correct address by scanning for I2C devices using an I2C scanner sketch if you’re unsure.