simsekm:
Hi again.I saw that most of RFID readers (which work at wiegand protocol) work with 5V. And Due supports 3.3V . So what should i do at this moment?
I know everyone must start at the beginning, but this does not inspire confidence that you are at the stage where you can take on the development of a safety-critical project.
Spend the nex 12 months "playing" with Arduni stuff - blinking LEDs, sweeping servos etc.. Learn how to build complex control loops. Use a 5v Uno for learning about RFID etc. Then when you know more it will be time to come back to your access control system.
...R