Tastiera a matrice 3X4 o 4X4

Schema elettrico tastiera a matrice 3X4

#include <Keypad.h>

const int ROW_NUM = 4; //four rows
const int COLUMN_NUM = 3; //three columns

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};

byte pin_rows[ROW_NUM] = {3, 4, 5, 6}; //connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {8, 9,10}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

void setup(){
  Serial.begin(9600);
}

void loop(){
  char key = keypad.getKey();

  if (key){
    Serial.println(key);
  }
}

Schema elettrico tastiera a matrice 4X4

#include <Keypad.h>

const int ROW_NUM = 4; //four rows
const int COLUMN_NUM = 4; //four columns

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3', 'A'},
  {'4','5','6', 'B'},
  {'7','8','9', 'C'},
  {'*','0','#', 'D'}
};

byte pin_rows[ROW_NUM] = {3, 4, 5, 6}; //connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {8, 9, 10, 11}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

void setup(){
  Serial.begin(9600);
}

void loop(){
  char key = keypad.getKey();

  if (key){
    Serial.println(key);
  }
}

Tastiera 3x4 - Codice password

#include <Keypad.h>

const int ROW_NUM = 4; //four rows
const int COLUMN_NUM = 3; //three columns

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};

byte pin_rows[ROW_NUM] = {3, 4, 5, 6}; //connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {8, 9,10}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

const String password = "1234"; // change your password here
String input_password;

void setup(){
  Serial.begin(9600);
  input_password.reserve(32); // maximum input characters is 32, change if needed
}

void loop(){
  char key = keypad.getKey();

  if (key){
    Serial.println(key);

    if(key == '*') {
      input_password = ""; // clear input password
    } else if(key == '#') {
      if(password == input_password) {
        Serial.println("password is correct");
        // DO YOUR WORK HERE
        
      } else {
        Serial.println("password is incorrect, try again");
      }

      input_password = ""; // clear input password
    } else {
      input_password += key; // append new character to input password string
    }
  }
}