| In a large greenhouse, the growth and yield of plantings has a great relationship with soil environment temperature and humidity. the growers mainly relied on usual planting experience to control the soil temperature and humidity by taking measures of irrigation and ventilation, and it is very optional and difficult to strictly control the temperature and humidity,and very very difficult to take timely and effective control. This article describes a wireless information collection and monitoring system of greenhouse soil temperature and humidity. The monitoring system consists of the slave of the system and the host of the system, the slave of the system working with solar power supply, can continually collect the data of soil temperature and humidity and wirelessly transmit them to the host, and at the same time the system can automatically adjust the temperature and humidity of soil according to the data by the opening of the solenoid valve and ventilation devices; By we can get soil temperature and humidity data and draw their curves through the host of the system while the host can also transmit the control parameters down to the slave wirelessly. First of all, this article analyzes the significance and the background of the topic, and introduces the domestic and international development of temperature and humidity control system of greenhouses, In addition, analyze the problems of existed systems, and propose a more feasible design. In this design, the high-performance microcontroller stc11f32 is selected as the core of the whole monitoring system.STC 10\11xx series designed by STC MCU Limited is fully compatible instruction set with industrial-standard 8051 series microcontroller with high-speed,low power and high reliability. The digital temperature and humidity sensor module db170 is selected, DB170 digital temperature and humidity sensor probe is a digital temperature and humidity sensors in cable-based sensors. The sensor integrates the sensor cell and the unit of signal process to output the digital signal. Db170 use advanced temperature and humidity sensors as its core components to ensure that it can produce the high reliable data and can have a long-term stability. and the system uses the wireless frequency hopping transceiver chip APC220-43, which is used to transmit wireless data. APC220 module can be transparent wireless data transmission, and with easy Mcu interface circuit design, and also offers low power consumption, strong anti-interference, the wireless transmission distance, ease of use. At the last part of the article also describes the display and control circuits. The entire system can collect the temperature and humidity data and can transmit data between the slave and the host The system structure is simple, with wireless data transmission, solar powered and no wiring to avoid the inconvenience in the process of the growing field operations, and can completely avoid the line due to system failure, while the measurement accuracy, high reliability and energy saving and environmental protection as well.The main aspects of the design is to do the following:First, to determine the whole system design, including the main function of the design to achieve technical specifications, system principles to achieve,according to which briefly describe the system components and Principle of work. Second, to design and made and debug the hardware circuits, Third, to Develop the software of the whole system include the software used in slave and the software used in the host.Many kinds of technology is applied in this system such as I2C bus programming, the application of wireless module, the application of several kinds of interrupt technology and object-oriented programming etc. The whole system incorporates the various technologies and finally design a practical soil temperature and humidity information wireless data collection and monitoring system, it has a broad prospect of application. |
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