The Research And Design Of Card Reader For Mobile Payment

Mobile payment which can also be referred to as mobile payment, is one way of modern electronic payment and a financial services way for purchasing goods or services by mobile terminals. We can complete payment by mobile payment, such as bank transfer, payment and shopping. With the improvement of mobile phone penetration, as a communications tool, mobile phone has become more and more as a payment tool in everyday life. Because of its portable and efficient features, it can resolve some unsolvable problem but traditional pay can't do and improve the efficiency of the traditional business process, so it has more extensive prospects for development. As the large-scale promotion for the third generation mobile communication, non-contact mobile payment has become a value-added service that the operators chase to have. At present, China's non-contact mobile payment has not formed a complete industrial chain. In addition, there is not a uniformed standard for mobile payment. And the2.4G payment solution technology is in the boost phase.In the background of the development, the article sums up the basic theory of RFID system and studies deeply for the basic principles of mobile payment systems and Communication protocol. The article designs a card reader for mobile payment by using the combination of hardware and software.In the design of hardware, we select the32high-security processor Z32chip from company's Product as the main controller. The main controller can complete the card reader's protocol-processing and interface-communication and module's logic controlling functions. Nordic's nRF24L01as the RF transceiver chip, can complete the communication with card in high frequency. Low frequency transmitter module is composed of C8051F330microcontroller with8-bit DAC, Amplifier drive circuit and coil. It can complete the process from the generation of low-frequency signal source to amplification and to emission.The software is designed with the idea of modular programming and structured programming. The software uses C language as the programming languages and Double MCU working mechanism. The software program of main MCU can complete serial communication for POS upper monitor, calling on the RF chip by SPI communication and operating card's procedures according to RF communication protocol. In addition, The software also can send command to control the low frequency modules. The software program of slave MCU mainly receive and process the command from main MCU and call on the underlying program to realize data's Manchester encoding work. In addition, The software of salve MCU also can send data by Manchester encoding to control the distance for swing card. At last, it also give an account of communication for main MCU with slave MCU.The test proves that the reader can work stably and reliably under the control of the POS. And the reader's time with card and power and other types performance index have reached the design of the desired objectives.