Arduino Password System



Author:9E 王詠濂


This is a password system made by Arduino Leonardo. Enter a password and it will show correct, or wrong. You can also code and decide what your own unique password should be in the 4×4 keypad.


How to Set Up a Keypad on an Arduino

The codes I changed

The parts that I changed includes both the appearance of it and the codes. For the codes, I changed the password into another password, and the number of the password is also changed. I changed that “Wrong” would appear if the password inserted was incorrect. For the appearance, I just carved a hole in the back to put the USB connector, but the rest is similar.

Program Code


1. Arduino Leonardo

2. 4×4 Keypad

3. I2C LCD Display

4. Wires

5. Keypad Library

6. I2C LCD Library

7. Wire Library (Should be installed already)


1. Buy the materials listed at number 6.

2. Attach the 4×4 keypad to Arduino Leonardo (with wires)

3. Attach the LCD Display to Arduino Leonardo (with wires)

4. Download the three libraries (Keypad, I2C LCD Library, Wire Library)

5. Copy the program code

6. Put the program into Arduino Leonardo

7. After the code works successfully, work on the outside

8. The outside look is optional, and I basically carved cardboard and put everything inside and stick two boards together.

Pictures of the finished product


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    • Category
      Safety, 康橋國際學校
    • Tags
      Cardboard and Arduino Leonardo Board


    • 簡述
      This is an Arduino password system that features an Arduino board, 4x4 keypad, and LCD Display. The LCD will start by "Password", and once numbers are entered or pushed from the Keypad, then the LCD Display will show "Correct" or "Wrong" based on the password given inside the code.
    • 作者
      9E 王詠濂

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