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How about a method of automatic identification through radio signals that can bring you security and control the access of people to a certain location? This is possible through radio frequency identification or RFID from the English Radio Frequency Identification. And it is the assembly of this system that I am going to teach you today.
This system works with a card or it can also be a key chain that has a chip inside it. Through the identification of the data of this card or chip is that it is possible to do access control, a method widely used in records of employee points, public transportation, libraries, among others.
Our goal, therefore, is to create a program in which we can either read an RFID card (or tag) or write the data to it. We use a WiFi NodeMCU-32S and an RFID-RC522 module.
It is important to note that we can store and retrieve data on these chips or cards remotely through devices, as these have up to 1k of memory.”

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