I am going to show my new lab about Arduino
Here is a simple lock box and I also set the password or code on that. Only the right code could unlock this box which is press first button 1 second and press secong and third button at the same time 1 second. Then press first and third button at the same time.Once it opened, you only need to press the last button and it will lock again.
Here's the video I recorded about lab