Design Of Campus Sign System Based On UHF RFID Technology

Radio Frequency Identification (RFID) is a technology of non-contact automaticidentification which can realize intercommunication by using wireless channel, is anInterdisciplinary Studies which integrate a number of modern technical field. It isbased on large scale integrated circuit technology, computer hardware, softwaretechnology, database technology and radio technology. The UHF RFID systemworking at860~960MHz has faster speed, longer reading distance and longer servicelife, etc. Nowdays, it has become a hotspot in RFID technology.In recent years, campus sign system developed a new research project with thestudent’s safety accident frequency. The RFID and SMS platform is combined, thelong identification distance of RFID and the convenience and speediness of mobilephone to receive text messages is reflected, the parent can timely understand whetherstudents have reached school safely, so as to realize communication between theparents of students and the school. Accelerating the process of the digital campus, butalso enhance the level of school management.This paper takes NXP’s ARM7microcontroller LPC1768and the reader chipAS3992of Austriamicroelectronics to design the hardware circuit. We design anddebug the RF module, such as the directional coutler, the power amplifier, thebalanced-unbalanced converter, the temperapture compensated crystal oscillator, lowpass filter, etc. And we also design the circuit of LPC1768, containing the reset circuit,the power circuit, the clock circuit, the key circuit, and so on. At the same time, theUHF system’s standard is explained in detail in this paper; In the software design, wefollow the principle of modularization and use embedded C language with KeiluVision4IDE to design read operation of tag program, anti-collision program whichis based on EPC Class1Gen2protocol, serial port communication initializationprogram between the PC and the Reader. We complete the the communicationsoftware between the PC and the Reader, the student management software, the SMSapplication software by using C#language, we use Sql Server2005to construct thedatabase. At present, sample machine has been accomplished which could identifymultiple EPC tags, the secure SMS has been sent successfully.