外文翻译

With the progress of the society and the needs of the production, the method of using wireless communication applications have penetrated into all aspects of the production and living.

In the industrial field, because of the bad production environment, the staff can not stay long time in field observation equipment is running normally, it need to collect data and to transmit data to a relatively good manipulation of the indoor environment, it will create data transmission problems. Due to large factories and a lot of need to transmit data, using the traditional cable data transmission way needs to be laid many long

communication line, waste of resources, take up the space, the operability is poor, there is an error in line. And, when the data patch in the motion state, the environment does not allow or not laying cable, data can't transfer, even at this time will need to use wireless transmission way data collection.

Wireless temperature acquisition and control applications, on agricultural production, the temperature monitoring of greenhouses, or the management of the granary, traditionally is to partition the artificial method of sampling, the workload is big, poor reliability. And

greenhouses and granary covers an area of big, detecting target dispersion, point is more, the traditional method can't meet the needs of the current agriculture development. Under the current level of science and technology, the development of wireless communication technology makes the collection temperature measurement precision and easy; In daily life, as people living standard enhancement, also gradually become intelligent living conditions. Now many families will install indoor temperature acquisition control system, its principle is to use wireless communication technology to collect the indoor temperature data, and according to the situation of indoor temperature by remote control operations such as ventilation, automatically adjust the indoor temperature, humidity, can improve people's living environment better.

Above all wireless temperature acquisition system has been successfully applied in

industry and agriculture, environmental monitoring, military defense, many important fields such as robot control, all wiring multifarious or do not allow the wiring occasions hope can through wireless solutions to solve. This paper, the main task is to design the

corresponding interface system, control the rf chips work, complete the reliable and stable wireless data communication, so the research and implementation of great practical significance.

Paper proposed nRF24L01 wireless communication interface design, nRF24L01 is a new type of monolithic rf transceiver device, working at 2.4 GHz ~ 2.5 GHzISM spectrum. Built-in frequency synthesizer, power amplifier, crystal oscillator, modulator, such as function modules, and combined with enhanced Shock Burst technology, including the output power and communication channel can be configured by the program. NRF24L01 low power consumption, in - 6 DBM power launch, working current is only 9 ma; ; When receiving, working current 12.3 mA, a variety of low power mode (power lost mode and idle mode) envoys to design more convenient.

Detection system are initially testing equipment has the function of single detection system is through the wiring one-on-one, connected to the central control room, realize

centralized detection, detection equipment are independent of each other, due to the progress of computer technology and the signal transmission technology, people can transmit the multipath signal, far in the central monitoring indoor display all the testing data of information, management and operation. Later, with the wide application of network technology and the development of wireless sensor network technology, the advanced field controller and PC to replace the work of the central control console, according to the operator instructions, can automatically detect the relevant data and information, so that the function of the detection system to network model by the original centralized mode development. Existing detection platform is mostly depend on the cable network, cable network of high-speed stability, meet the requirements of most industrial detection system, but the cable can only according to the conductive medium line to

transmit data, thereby increasing the in wiring layout, interface Settings, line detection and a series of work for transmission route, and the work of the inevitable destruction, waste of interface defects, and waste a lot of material resources and financial resources. In

addition, if testing equipment is not wiring, is difficult to use cable network, in this case, the wireless network technology. Compared with wired networks, wireless network technology can transmit data information directly, don't need to be in the process of transmission conductive medium. Wireless detection system, can realize real-time detection,

perception and gathering network distribution of monitoring objects in the area of all kinds of data information, and processing, complete the data acquisition and testing tasks.

The birth of the wireless network technology can be traced back to the 1970 s, then there is the traditional sensor adopts point-to-point transmission way connected network, thus constituted the embryonic form of sensor network, which is the first generation of sensor network. With the continuous development of related disciplines and progress, sensor network not only has the capability of the data acquisition and also can achieve a variety of information integrated processing, and through the Internet with a sensor controller, formed a comprehensive information processing ability of detection network, this is the second generation of sensor network. Most sensor network based on cable transmission mode of the two generations, because the cable transmission mode inherent limitations, so as to make the sensor network of the two generations don't get too big development. Since the late 1990 s, from cable era into the wireless sensor network technology era, the research of wireless sensor network to begin from now on. The first generation of wireless network system is composed of a large number of sensor nodes with wireless

communication, these nodes are more jump form self-organized wireless network

communication way. Main function of the wireless network is perception and gathering data information, and processing network coverage area is detected in the object's data information, and through the self-organization of wireless jump more communication network of information collected will be sent back. Due to the tremendous application value in the wireless sensor network (WSN), which has caused many countries of the world of industry, military industry, academia, of great importance to it.

Domestic at present mainly concentrated in the hot topics in the study of environmental perception, a few domains such as smart classrooms, wireless sensor network technology application in environmental testing to. Detection technology development is closely

related to the development of the latest technology, users keep ease of detection and real-time put forward higher requirements. So must be better and more timely application of the latest technology, so as to make the remote detection continuously development, constantly meet people's needs. Generally speaking, the domestic research on sensor networks is still in its beginning stage, but the sensor network is a kind of emerging

technologies, the difference of domestic and international level is not very big, predictably, sensor network technology will be along with the development of related technologies in China and gradually perfect and mature, all sorts of function of sensor networks in the near future will be widely used in various fields of society, in a timely manner to carry out the influence of future human life at the forefront of science and technology research, on the whole national society, economy, national defence will be of great strategic

significance.

1.4 the analysis of the design task

The design of this system adopted in 2.4 GHz frequency band nRF24L01 rf chip, and has low power consumption MCU AT89C51 control realization of short distance wireless data communication. The interface design of low cost, low power consumption, high

transmission rate, software design, simple and stable and reliable communication, etc. The whole system includes both send and receive, by nRF24L01 wireless data

communication transceiver module to realize wireless data transmission. Send part with single chip microcomputer AT89C51 as the core, the use of temperature conversion chip DS18B20 temperature real time acquisition and through digital tube display. Will collect the temperature of the wireless transmit to the receiving part, then on the digital tube display.

To AT89C51 can make two minimum system (sending a control, a control accept part) minimum system includes power circuit, download using the JTAG interface circuit and main control chip and some basic peripheral circuit.

For DS18B20 temperature detection module, the hardware part is simple, software timing due to is single foot transmission time control precision demand is higher, to be precise. Digital tube display part is relatively simple but an important role in the debugging process, is to show the hardware and software so that the necessary condition of cannot be ignored. In addition to lower the power output of the microcontroller, using the latch of digital tube driver.

Wireless transceiver module adopts the Norwegian company's nRF24L01 (Nordic) and the peripheral circuit, software part must be familiar with internal marks and control registers and data channels, transmission frequency power and the transceiver to facilitate programming and so on.