The Design And Implement Based On Ds18b20 Multicast Wireless Temperature Measure Instrument

The article mainly introduces the application of stone's throw wireless multicast temperature measure instrument based on digital temperature sense organ DS18B20 and single chip wireless receiving CMOS chip-nRF401 in vegetable greenhouse. The core of the system is SCM, which applies sense organ technology,wireless receiving technology and computer technology to real time control and inspect a lot of spots' temperature in the vegetable greenhouse. Each detecting unit can complete its own function separately, at the same time, according to the orders of main control computer it can real-time or timely gather the temperature data, the gathering data not only can be showed on the spots, but also can be transmitted to PC by SCM nFR401 wireless receiving chip, thus which can realize the long-distance.PC takes charge to control lower computer to detect each measuring temperature spot,to gather detecting data, and to coordinate and show the measuring results; PC also carry through further analyses,keeping in the archives,disposal and investigation, thus process Monitoring turns more direct-viewing. Superior computer can communicate and coordinate each other. PC also can set the upper limit and lower limit of temperature, superior computer can send the controlling order to lower computer immediately, when the environment temperature value of the greenhouse exceeds the advance setting upper limit or lower limit, SCM can run the alarm system to give an alarm, thereby to adopt corresponding measures to control the temperature of the greenhouse.The design is based on the practical requirement and theory knowledges, adopting the newest technology, from the hard ware design and soft ware design aspects, demonstrating amply design train of thought and system collectivity structure of realizing multi-spot temperature data detecting and wireless transmission project, introducing many problems, such as system elements, hard ware circuitry structure, soft ware design flow chart,the power source management and electromagnetic compatibility of each part. During the system design progress, to consider Capability/price Ratio adequately, to adopt low price,little power,steady capability component. Application shows, the temperature detecting machine has the following advantages:more juncture,long wireless transmission distance,convenient spread,low price and easy to form gathering system, which applies for detecting temperature of several greenhouses, it can show temperature of the vegetable greenhouse and it is easy to carry out long-distance control, furthermore, it can save time and energy. It can guarantee the growth of vegetable effectively and provide a steady environment for the growth of vegetable.