Design Of Intelligent Water Meter System Based-on CPU Card

At present, our country's traditional man-power way of check the data of water meter has bring more and more problems to the governors of water, Such as increases the labor intensivity of the workers, make much money to consumed, and give the chance of users to steal water or refuse to give money. At the same time, along with the "golden card project", more and more high-tech production which used IC card is coming to people's daily life.But common IC card is not safe enough to protect the important information. In order to cease the occurrence of stealing water and the water leakage, this paper studied one kind intelligent water meter system which use the CPU card for core technologies.On the hardware, this paper designs a series of circuits around the MSP430F413 micro-controller which has the advantage of low power. The circuit contains: card interface, electromotor driving, power supply detecting, water flux measuring, ESAM interface module and LCD interface. This design can not only make each external circuit do it's own work, but also has the advantage of low power by optimizing the external module and give the correct connection between the IO of MSP430 and other electronic equipment. The interface modules and transceiver modules have been developed with high performance on electromagnetic immunity.On the software, the system uses the C language to achieve water meter's main function, and the programming environment is IAR Embedded Workbench. The whole software is divided into several parts. They work together to transfer information from CPU card, make the electromotor work well, drive the LCD to display, and calculate the remain money by detecting pulse. It can give the user not only the information of remain money but also other information such as time and voltage of the power supply. The management system is designed by VC6.0 tool. In consideration with the problems after it had put into market, the system has the completed function of big prepay trade with the friendly and fancy interface, and give the user and governors a good platform to trade.This paper pays attention to theories as well as practice, and after doing research, it has gotten abundant information and experience. Further more, this paper has got a lot of knowledge about the CPU card transfer protocol , the encrypt arithmetic, the low power consumption, the security and the stability, which ensures the CPU card water meter widely put into production. the end, this paper also discusses the further improvement in this system.