【正文】 circuits kernel, therefore we no longer need to use a single MCU to control the circuit, and this save us a lot of cost.A. Mobile NodeThe mobile node is the end device of a Zigbee network that can be carried by miner。s life. Currently most widely used orientation method is GPS satellite positioning, it is a high precision, allweather and global multifunctional system with the function of radio navigation, positioning and timing. But the GPS positioning method is not suitable for the underground work environment of coal mine, once you enter the underground, it cannot receive satellite signal, thus unable to achieve targeting. We need to consider how to use wireless network to realize positioning function, means using wireless signal between the munications of devices for positioning. The existing distance measuring technology between the wirelessdevices basically is the following kinds of methods: TOA, TDOA, AOA and RSSI. About the TOA method, the distance between the two devices is determined by the product of the speed of light and transmission time. Although the precision of this method is accurate, but it require a precise time synchronization, so it demand hardware is higher.TDOA technology need ultrasonic signal，which is setting on a node with receive and transmit function. When measure the distance, it can sent ultrasonic wave and wireless signals together. By measuring the difference between two signals arrival time, we can calculate the distance between two devices. Using this method can also obtain accurate result, but the method need to increase ultrasonic sending and receiving device on the node circuit, it will increase cost.AOA technology needs to install multiple antennas through the nodes so it can obtain adjacent nodes’ signals on deferent directions. With this it can determine the location information from number of adjacent nodes and calculate its own position. This method not only need to add additional hardware, but also it39。s point of view, CC2431’s hardware location engine has a very simple API interface, as long as writing the necessary parameters and waiting for calculation, it can read the location results.The hardware location engine is also based on RSSI technology. The localization system includes reference nodes and blind nodes. The reference node is a fixed node that located in a known position, the node know their place and send a packet notify to other nodes. The blind node receives packets from reference nodes, which can obtains reference nodes’ location and the corresponding RSSI value and put them into the hardware location engine, and then the blind node’s location can be read from the engine. On the surface, using the CC2431 hardware location engine targeting the program as a good choice, but considering the practical application, it will encounter the following problems. First of all, we have choose the CC2530 as the main chip of fixed nodes of the system, its internal programs is running in Zigbee2007 protocol, but CC2431 as a early chip, it applies only to Zigbee2006 protocol. In the munications between CC2431 and CC2530 that will have patibility problems. Secondly, CC2431 hardware location engine use the distributed puting, all mobile nodes’ location are calculated by themselves, and then they upload information to the gateway node, this will not only occupy the mobile node processing time, still it can take up more network resources. For this reason, we have to shelve this approach, consider how to implement location by using CC2530 chip.B. Software Location Engine If we want to use CC2530 to implement location function, that we must write software location engine by ourselves. Because that chip do not have a hardware location engine inside of it. This software location engine is still used RSSI technology。s not suitable for utilize.RSSI ranging is a cheap and easy technology. By using this method, we don39。 it is enough to put all PCBs, sensors and battery in it. Taking into account the small shell of the explosive performance is not very good, the design of PCBs and the selection of ponent are all carried out the safety assessment.B. Fixed NodeFixed node is installed in the wall of the underground tunnel. Because it is big than the mobile node, it is not appropriate to carry around. The circuit of the fixed node is almost same with the mobile node, it also use a CC2530 chip as core processor. Because of underground tunnels generally deploy with power cable, fixed nodes can use cable powersupply modes. At the same time, because we use wireless signal transmission, the deployment of new fixed nodes bee very convenient, which also resolves the problem of the signal lines deployment.As a fixed node, the minor who is doing work may far from it, in order to facilitate the miners observed environmental data around the fixed nodes, it uses LED digital display. At the same time, the large current LED lights and buzzer are designed in the circuit。 they are using Zigbee protocol for wireless transmission of data. Because the fixed node is also using wireless data transmission method, so it39。在這次畢業(yè)設(shè)計(jì)中也給我很大的幫助。本次設(shè)計(jì)主要涉及到硬件設(shè)計(jì)和Zigbee協(xié)議編程兩方面的內(nèi)容。目前市場(chǎng)上的近距離無(wú)線通信技術(shù)有很多種，如無(wú)線局域網(wǎng)WiFi、藍(lán)牙、IrDA、UWB、RF等。 展望在本次設(shè)計(jì)中，盡管達(dá)到了設(shè)計(jì)的要求，但系統(tǒng)比較簡(jiǎn)單，可移植性差，在外部環(huán)境復(fù)雜的實(shí)際生活中實(shí)用性不大。圖61 Zigbee調(diào)試接口第7章 結(jié)論與展望 結(jié)論隨著計(jì)算機(jī)軟硬件技術(shù)、網(wǎng)絡(luò)技術(shù)和工業(yè)綜合自動(dòng)化系統(tǒng)整合水平的不斷發(fā)展，對(duì)監(jiān)控?cái)?shù)據(jù)傳輸?shù)膶?shí)時(shí)性、數(shù)據(jù)接口的開放性以及數(shù)據(jù)鏈接的安全性的要求越來越高，有線控制網(wǎng)絡(luò)的局限性也越來越突出，無(wú)線的優(yōu)勢(shì)也越來越明顯。(4)上位機(jī)通訊程序測(cè)試：以1s間隔頻率發(fā)送命令(24小時(shí)以上)，查看系統(tǒng)是否能及時(shí)返回?cái)?shù)據(jù)，返回?cái)?shù)據(jù)是否正確。(2)單片機(jī)與無(wú)線模塊通訊測(cè)試：?jiǎn)纹瑱C(jī)每采樣到一次傳感器信號(hào)，處理后及時(shí)將數(shù)據(jù)發(fā)送到無(wú)線模塊，通過觀察電路板上的通訊指示燈觀察無(wú)線模塊是否接收到數(shù)據(jù)。長(zhǎng)時(shí)間運(yùn)行程序并檢查芯片工作情況與工作狀態(tài)(溫度、電壓等)。程序初始化傳感器預(yù)熱鍵盤掃描與鍵值處理A/D轉(zhuǎn)換平均值法濾波線性化處理進(jìn)入警報(bào)處理程序濃度強(qiáng)弱顯示設(shè)置指示燈狀態(tài)Y是否超過報(bào)警開始N圖52 煙霧傳感器流程圖第6章 系統(tǒng)性能測(cè)試與評(píng)述 硬件測(cè)試電路板焊接完畢后，找出硬件整體上的錯(cuò)誤，如接口松動(dòng)、接觸不良，電源不穩(wěn)定等。 煙霧傳感器程序本論文中，對(duì)于煙霧傳感器主要解決的問題是檢測(cè)煙霧傳感器的煙霧濃度信號(hào)，然后對(duì)信號(hào)進(jìn)行AD轉(zhuǎn)換，數(shù)字濾波，線性化處理，濃度強(qiáng)弱顯示。(3)數(shù)據(jù)傳輸功能：采用標(biāo)準(zhǔn)的MODBUS協(xié)議通過上位機(jī)修改系統(tǒng)參數(shù)。液晶顯示接線如下圖410所示。但是zigbee可以通過組網(wǎng),以多跳的方式來實(shí)