#include <Keypad.h>

#define ROW_NUM 4
#define COL_NUM 4

char key = '\0';
String input_password = "";
String user_password = "";

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

byte pin_rows[ROW_NUM] = {19,18,5,17};
byte pin_columns[COL_NUM] = {16,4,2,15};

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

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  train();
  delay(3000);
  Serial.println("You are now trained");
}

void loop() {
  // put your main code here, to run repeatedly:
}

void train(){
  Serial.println("Welcome to personal lock Services");
  delay(1000);
  Serial.println("Print # to set new password");
  while(true){
    key = keypad.getKey();
    if(key == "#")break;
  }
  set_new_password();
  check_password();
}

void set_new_password(){
  Serial.println('Enter new password. press # when password set: ');
  while(true){
   
  }
}

void check_password(){
  delay(3000);
  Serial.println("Enter Password. Press # when password entered : ");
  while (true){
    
    
  }
}