Piston door with code 3 (surely last)

Once again find again a way to improve the system efficiency

(to the detriment of the size but who cares it's underground)

The code is the one you can see on the screenshot
Just enter it, then press the button, you have all your time to go through the door, deactivate the code, enter the building then press the button inside, the door close, then to exit press the button, re-enter the code and press the button to close from the outside

To change the code see this project

The world save contains also projects I don't plan to upload, and projects I actually plan to upload later