Design Of Programmer & Meter Reader Of Photoelectric Direct-Read Meter

With the development of information technology, AMRS (Automatic Meter Reading System) is widely used in reading the meters of water, electric and gas which are indispensable in everyday life. The system that makes use of handheld meter reader is more popular among numerous AMRS.The objective of the project is to design an intelligent instrument like handheld meter reader, distinguished as programmer & meter reader of photoelectric direct-reading meter, programmer & meter reader for short,which is provided with not only the traditional meter readers' function such as reading meter, querying information, uploading and downloading data, but also strongpoint that the traditional meter readers don't have. These strongpoint root in the particular characteristics of the photoelectric direct-reading meter, namely, the meter is completely power-off unless it receives the read instruction. If so it will send the indicating value to the meter reader. Designed basing on this strongpoint, the programmer & meter reader makes it possible to get rid of the data collector from the traditional AMRS, which makes lots of sense to the reconstruction of the big city's cosmical AMRS. The programmer & meter reader will greatly reduce the cost of the reconstruction which needs thousands of data collectors and save the maintenance cost. In addition, considering the production compatibility, the programmer & meter reader reserves all the functions of the traditional meter readers.The programmer & meter reader, which is a powerful PDA (Personal Digital Assistant), comprises the following parts: two ways of communicating with the meters, which are Infrared and RS485; two ways of exchanging data with the computer, which are USB and GPRS; NANDflash data memory; input and output devices; the voltage monitor; power manager; ARM's minimum system including NORflash, SDRAM, peripherals and so on.Block-based method is adopted in both designs of the hardware and the software. In the process of designing hardware, the system which is modularized according to its functions is combined by using PTOTELDXP's hierarchical schematic design method. The software's modularization, also based on functions, follows these rules: independence and integrality; convenience to join and separate; versatility and portability; no influence on the system's function. Each module comprises driver layer and application layer. The driver layer deals with operations on hardware and provides calling interfaces to the application layer. The application layer, possessing favorable portability, is immune to the changes of the hardware.After one year's effort, the author accomplishes the design of programmer & meter reader and computer software matching with programmer & meter reader and works out several universal schemes which can be referred in the design of the embedded systems, such as:1) data storage and information query scheme,DBF data base file driver + Yaffs file system + NANDflash data memory.2) The design method of friendly, extendable Human Computer Interaction.3) Soft switcher.4) The way of matching the different level logic.5) The low-cost way of extending serial ports.6) USB and GPRS data transfer scheme.The thesis firstly presents the background and the objective of the project. Secondly some basic knowledge and protocols involved in the thesis are introduced. Thirdly, the design of the hardware and software is detailedly described. Finally, some proposals are presented for the improvement.