Controlling the door lock with a keypad
In the following image, we see a keypad with a lock. This section can be merged along with the last project. This device can be controlled from your Raspberry Pi Zero or your Arduino board:

 Code to access using the keypad
You can now either copy the code inside a file called Project_keyboard_Access_Control.ino, or just get the complete code from the folder for this project using the Arduino IDE:
void captura()
{
tecla = customKeypad.getKey();
if (tecla)
{
digito = digito + 1;
if(tecla==35){tecla=0;digito=0;valorf=0;lcd.setCursor(0,0);lcd.print(valorf);
lcd.print(" ");}
if(tecla==48){tecla=0;}
if(tecla==42){tecla=0;digito=0;valor = valorf;}
if(digito==1){valorf1 = tecla; valorf=valorf1;lcd.setCursor(0,0);
lcd.print(valorf);lcd.print(" ");}
if(digito==2){valorf2 = tecla+(valorf1*10);valorf=valorf2;lcd...