Design Of Access Control System Using STM32 Micro Controller

With the rapid development of technology,the entrance control management system has been used in a variety of public places.It not only has the characteristics of autonomy,but also has the advantages of saving human cost and reducing the rate of error.Set up the identification office at the entrance and other places,users need to rely on their access control cards or all kinds of passwords,such as fingerprints,iris,and so on.However,the security of the password identification is not strong and the operation is tedious.Once it is leaked to the outsiders,it will cause additional risk.The security of the iris is high,but the cost is high and the difficulty is great.Now the radio frequency and fingerprint are becoming more and more mature.The radio frequency identification card and fingerprint have generally replaced the traditional IC card and become the entrance of the entrance guard system.Technology.The entrance guard system is mainly used in shopping malls,schools,enterprises,communities and factories and other places.The advantages of the system are the efficient management of the security of each entry and exit,and the effective prevention of unrelated personnel.We can adjust the rights and limits of the different rights and scope of the cards according to the right of different personnel in the environment at that time.To realize the rational management of the personnel and access channels,and then to realize the function of one card function,such as attendance,electronic patrol,conference signing,consumption management,library borrowing,parking management and so on.This paper mainly designs an embedded access control system.The access control system is mainly divided into two parts: hardware and software.The hardware is composed of power supply circuit,control circuit,display circuit and so on.The control circuit uses STM32F103C8T6 chip as the core controller,connecting memory chip,RF reading card chip,fingerprint identification,relay and LCD display screen.The MFRC522 chip is used in the circuit through the RF reader,and the fingerprint is FPS200.The radio frequency signal collected in the card is converted to binary data to the controller,and the LCD display will show the information of the details of the card.In the software,the control system is built on the basis of the function library of STM32.The control system is monitored by multi thread.Through multiple interrupt processing functions,the card,the door,the sudden alarm and so on are detected,and the corresponding processing is carried out.In addition,a set of communication protocols is reserved for the software system,and the 485 bus is used.The host computer can make the information of the entrance guard system in real time.It can make the user inquire at the entrance entrance card record at any time,so as to ensure the security and rigor of the system.With the above design plan,we complete the design of the whole access control system.The entrance guard system is composed of embedded controller,reader,reader supporting antenna,fingerprint identification module,display module,electronic lock,relay and other circuits.After the corresponding tests verify,this set of access control system has perfect functions and has practical use value.