📺 Secret Messages (LCD Screen)

Write your own messages on a 16×2 LCD screen! Press the button to switch between two different screens and create your own fun messages.

Coming Soon (TODO)

Instructions

1. Change the four messages below and upload your code.
2. Press the button to switch between your two screens.

String message1Line1 = "HELLO!";
String message1Line2 = "PRESS BUTTON";

String message2Line1 = "YOU FOUND";
String message2Line2 = "SECRET MODE";

Challenges

⭐ Easy

Write:

• 👋 Your name
• 😊 Hello World

---

⭐⭐ Medium

Create:

• 😂 A funny joke
• 🎂 A birthday message
• 🎮 A game start screen
• ❤️ A message for a friend

---

⭐⭐⭐ Design Challenge

Create your own two-screen story!

Ideas:

• 🚀 Countdown → Blast Off!
• 👻 Knock Knock → Boo!
• 🐉 Dragon → Beware!
• 💎 Treasure → You Found It!
• 🎉 Ready? → Let's Go!

Story Name: _____

Wiring

Component	Arduino Pin
LCD SDA	A4
LCD SCL	A5
Push Button	2
LCD VCC	5V
LCD GND	GND

Setup

This uses the standard setup instructions.

This does use the libraries: LiquidCrystal_I2C

Starter Code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int BUTTON_PIN = 2;

String message1Line1 = "HELLO!";
String message1Line2 = "PRESS BUTTON";

String message2Line1 = "YOU FOUND";
String message2Line2 = "SECRET MODE";

bool lastButtonPressed = false;

void printLine(int row, String text)
{
    lcd.setCursor(0, row);

    while (text.length() < 16)
    {
        text += " ";
    }

    lcd.print(text.substring(0, 16));
}

void showMessage(String top, String bottom)
{
    lcd.clear();
    printLine(0, top);
    printLine(1, bottom);
}

void setup()
{
    lcd.init();
    lcd.backlight();

    pinMode(BUTTON_PIN, INPUT_PULLUP);

    showMessage(message1Line1, message1Line2);
}

void loop()
{
    bool buttonPressed = digitalRead(BUTTON_PIN) == LOW;

    if (buttonPressed != lastButtonPressed)
    {
        if (buttonPressed)
        {
            showMessage(message2Line1, message2Line2);
        }
        else
        {
            showMessage(message1Line1, message1Line2);
        }

        lastButtonPressed = buttonPressed;
    }
}