1. 4.Read card part design Design description: U2270B is a typical transmission frequency of 125 KHZ RF chips. This chip U2270B's output connect the MCU input capture port, through the microcontroller analysis IC card in figure 3. U2270B bear the frequency from 100 to 150 kHz. The modulation mode is Manchester code and binary phase code. U2270B power supply is 5V regulated power supply or a 12V car battery. It can provide energy for the RF field, which used in short distance. The peripheral circuit is simple. U2270B also has the ability to fine-tune signal, but its distance is 4 ~ 6cm. U2270B also has the output voltage function of the microprocessor or other peripheral circuit as the power supply. It can be strengthened distance from bridge diodes. Entrance guard control system consists of a PC, entrance guard control equipment, wireless transmission platform, card reader, electronic locks, AC - DC Power supply, card, management software, such as several important parts. Entrance guard system hardware is mainly composed of entrance guard controller based on STC12C5A60S2 microcontroller, lock system, card reader, non-contact IC card, RF radio frequency wireless transmission equipment, power supply and other peripheral equipment. Entrance guard control system consists of a PC, entrance guard control equipment, wireless transmission platform, card reader, electronic locks, AC - DC Power supply, card, management software, and some other parts. Entrance guard system hardware is mainly composed of entrance guard controller based on STC12C5A60S2 microcontroller, lock system, card reader, non-contact IC card, RF radio frequency wireless transmission equipment, power supply and other peripheral equipment. Entrance guard controller: It is the core part of the entrance guard system, in charge of the whole system of the input, output, information processing, storage, and control. Its tests and verifies the effectiveness of inserted card through its input information. Entrance guard controller performance can affect the stability of the system and directly affects the customer's life and property safety. Nowadays we usually apply non-contact IC card. Because of its operation without contact prevents wearing out, saves chip packages inside the card, and prevents corrosion. Reader: with non-contact IC card controls part of the data exchange. When approaching non-contact IC card transmitting antenna can provide energy to verify the validity from card reader analysis and have access to deliver result through returned data. To confirm the validity of the card reader analysis, and transfer the results to the controller. Electric control lock: the implementation of entrance guard system parts, electric control lock when the power is on, in accordance with the requirements of the safety regulations. RF radio frequency transmission equipment: entrance guard system of wireless transmission platform. It utilizes RF radio frequency microwave as a carrier of wireless transmission, using the single chip microcomputer and PC communications. The Access Control System Design Zheng Duan, Advisor: Prof. Navarun Gupta Department of Electrical and Computer Engineering, University of Bridgeport, CT. Abstract This poster describes the access control system. This design is better than the non- contact IC card form, the contact IC card form, the magnetic card form and other cards. It is based on RS232/485 communication to receive data and send data to achieve the control management, real-time monitoring, storage, abnormal alarm, access records query functions and storing 2000 users’ information. It also applies the modular design concept. With external IC card chip U2270B collection and analysis through STC12C5A60S2 master chip IC card number, the card can read and write as the range of 300-400mm. This system includes swiping card module; detection button and MCU pin, the pin is low level twice in a row to achieve the button pressed the button module; neither swiping card nor the button, the door opens to achieve mechanical door module; drive motor using a circuit composed of four NPN transistors, the output level to achieve the level of the motor forward and reverse functions, enabling the motor drive module. In this design of access control, the circuit is simple, simple to apply, highly reliable, responsive, easy maintenance, wide application and low prices with wide ranges of application. It can be replaced in most cases the use of contactless IC card. Introduction Entrance guard system, namely the inward and outward entrance guard system, it is the inward and outward channels control system, the system control of all kinds of personnel in and out, and their activities in the related area. The basic principle of controling is producing different card levels and setting password in advance according to different information. When people insert a card, the card reader that installed inside the door can identify heat, number or other information, which response to the archived information, open or carry out an alarm as a result. Through the entrance guard system, which can effectively control personnel activities. It is currently solving important department gateway effective measures for implementing safety management. Apply to all kinds of confidential departments, such as a bank, hotel, office, computer room, the armory, confidential room, intelligent community, factory, etc. Results 1.STC12C5A60S2 / AD/PWM series function profile and the minimum system design of the single chip microcomputer STC12C5A60S2 / AD/PWM series single chip microcomputer is produced by STC micro company. It is a single clock cycle machine and a high speed/low power/super anti- interference new generation of 8051 single chip microcomputer. The instruction code is fully compatible with the traditional 8051, and the latest single-chip is faster 8 to 12 times. Interior includes MAX810 specialized reset circuit, 2-way PWM, 8-way 10 bit high-speed A/D conversion (250 k/S) for motor control, it is strong interference. STC12C5A60S2 pin diagrams as showed in figure 1. 2.Power supply module design Design description: provide chip L7805 12v power supply in figure 2. The main purpose of adding capacitance of input and output is maintaining stability when input 12V voltage and 5V voltage which transformed by chip 7805 via filtering process. 3.Rf module design EM4100's all the data is 64 - bit, it contains 9 start bits (the value is' 1 '), 40 bits (8 information bits + 32 bits), 14 odd parity bit (10 lines check + 4 columns check) and 1 end stop bit. When EM4100 transfers information to the reader or PC, first is 9 start bits, and then sending 8 information bits or the version code, and then transmitting 32 bits. 14 odd parity bits and 1 stop bit are used for tracking 40 data information. When the EM4001 is initialization, in turn this 64 - bit data will be output repeatedly, until the cards left the base station. Figure 1:STC12C5A60S2 Pin Diagram. Method PDIP-40, STC12C5A60S2 Figure 2:Chip L7805 12v Power Figure 3:Read card part design Conclusions The entrance guard system can serve a long time, because it adopts an ID card without contact and wear. It is convenient and safe. Microcomputer can record all the data and handle a double-way control. Also,it's hard to make a card copy. The controller and card reader are designed to parts: the system controller installed indoors, only card reader input line in the outside, other all line of indoors and the card reader transfer a digital signal. Therefore, without effective cards or passwords, no one can enter. With high technical development, the controller is transferred data from the LAN management center. The management center changes position at any time, the entrance guard system dosen't need to rewire. It is easy to implement the network control or the distance control, but it needs to rely on the stability of the local area network (LAN). Entrance guard system is highly prior to the simple doorways and key management. It has gradually developed into a set of complete access management system. The entrance guard system creates a safe environment and it is effective for personnel attendance management.