Arduino Leonardo - Electronic Lock

Placed on 2020-06-22

The keypad

For the keypad to work we can use the keypad library. The library is easy to use and initialize.

To initialize the keypad library we first have to specify how many rows and collums there are on the keypad, then we have to make a KeyMap. This means that we have to tell the library where every key is located on the keypad itself. After that we have to specify where we connected the keypad on the Arduino .

The Initialization of the keypad library

#include <Keypad.h>

const unsigned char ROWS = 4;
const unsigned char COLS = 3;

char KeyMap[ROWS][COLS] = {
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'*', '0', '#'}
};

byte rowPins[ROWS] = {23, 22, 21, 20};
byte colPins[COLS] = {19, 18, 8};

Keypad customKeypad = Keypad(makeKeymap(KeyMap), rowPins, colPins, ROWS, COLS);

Then to use the keypad, we have to make a function that checks if we have a keypress.

Check for a keypress function

char WaitForKey() {
  char key;
  key = customKeypad.getKey();
  while (key == NO_KEY) {
     key = customKeypad.getKey();
    }
  return key;
}

Previous page 5. The Servo Current Page 6. The code - part 1 - The Keypad Next page 7. The code - part 2 - The LCD 1. Introduction 2. The Schematic 3. The Keypad 4. The LCD module 5. The Servo 6. The code - part 1 - The Keypad 7. The code - part 2 - The LCD 8. The code - part 3 - The code 9. The code - part 4 - More codes 10. The code - part 5 - Setup and Loop 11. The full code Posted by Sander Speetjens

Arduino Leonardo - Electronic Lock

The keypad

The Initialization of the keypad library

Check for a keypress function

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