| It is of great significance to improve the overall efficiency of agriculture by developing information agriculture, equipping the agriculture industry with modern information technology and accelerating the development process of agricultural informatization. Data acquisition is not only the front end of the information technology but also the foundation of data transmission and processing in a correct and reliable way. The high consumption and low efficient of agricultural production, the complexity of wild environment and dispersive information increased the difficulty of agriculture information collection. Furthermore, we had relatively few agricultural data collectors. Therefore, development of low power programmable data logger has certain research value with the actual meaning.A universal low-power programmable data collection storage system was designed by MCU software and hardware design methods combined with compilation technologies. MCU MSP430F169 produced by Texas Instruments Incorporated (TI) acted as the kernel of the whole system. The periphery circuit mainly consists of signal processing unit, U disk storage unit, communication unit and real-time clock unit. Six-channel voltage input signal can be converted using two AD7706 which are complete analog front-ends with PGA. In order to realize massive storage, MCU can read and write the USB Flash Drive by virtue of the USB118 series embedded module (U disk document module) manufactured by Xi'an Dataie Electronic Co. Real-Time communication of the high-grade microcomputer (such as PC) and data acquisition system is realized by the interface of RS-232.Precise calendar clock chip PCF8563 takes the real-time clock source for data acquisition system. Furthermore, it can make the time collect using timer which is configured by MCU MSP430F169 and modify the time interval through software. SCM built-in D/A converter can convert digital signals for analog output. Also, referring to the principle and methods of modularity, anti-interference, low power consumption, the system was designed and developed. The principle and methods can reduce the area size and the power dissipation of the system. The low power design results in a significant increase in system battery operating life. The low-power data acquisition system basically meets the design requirements, which has the characteristics of compact, lower power consumption, programmability, great capacity and universality. The MSP430F169 can document the data sampling and processing in the files format into a mobile storage. The Removable Device (such as U disk) is commonly used, that comply with the USB communication protocol. Thus it realized the online storage of massive data. This is the unique characteristic of this dissertation. Moreover, the development of simple language design rules and precompiler for the programmable data logger is an important trial of this dissertation. According to the principle of compiling, the precompiler using advanced program language c + + was designed and realized. It provides a technological method for data sampling, processing and controlling, due to its programmability, reliability and convenient application. |
