To Research And Realize The Reader And Transponder Of RFID Based On AVR

As a non-contact automatic identification technology, radio frequency identification (RFID) technology is able to make use of radio frequency signal to deliver information through a space matching, and achieve recognition by way of the delivered information. Compared with other identification technologies, radio frequency identification technology has many advantages and has been extensively applied in many fields. Its great potential for the development and application makes it very critical and urgent for the design and research on the reader and transponder—the key part of the RFID system, whose research and development is of high practical value for the RFID technology's maturity and wide application.Based on the operating principle of RFID, the subject makes use of the RFID technology to design a wireless Chinese Character Recognition System, so as to realize the function that character information is transmitted wirelessly by the reader to the passive electronic tag (transponder in this design), character information is stored in the transponder, then the reader reads the stored character information in the transponder and displays it in the LCD panel. Specific studies are as follows:Based on the analysis of the operational principle of RFID system, this paper, with the design objectives and requirements of this subject, determines the overall scheme of the system:with low power AVR microcontroller ATmega168V as the control core, the system is modulated by the 2ASK mode, making use of the electromagnetic coupling of the coil to complete the transmission of energy and information between the transponder and the reader and then realize the short distance half-duplex communication; the chip realizes the input of Chinese characters through the T9 Pinyin input method, using the PS2 keyboard and monochrome 240×128 graphic LCD as the human-computer interaction device; the system uses highly efficient class C tuned power amplifier to realize the fuction of the transponder's non-battery-powering and its information protection against the power-down as well as other fuctions that the reader stores Chinese characters into the transponder, reads the characters from the transponders, or self-erases the Chinese characters.Finally, we have carried out testing on the hardware and software of the designed reader and transponder. Tests were conducted on the carrier frequency, transmission distance, power, recognition time and the ability of Chinese character input. And the test results showed that the designed wireless character recognition system met the design goals.