Design And Implementation Of Long-distance And Low-power Wireless Sensor Network Terminal Node

As the demand for the development of the Internet of Things is getting higher and higher,the requirements for transmission and communication technologies are getting higher and higher.However,the traditional internet wireless transmission technology has the contradiction of long distance and low power consumption,such as the wide area network composed of the LAN 2.4GHz WiFi technology,Bluetooth technology,Zigbee technology and so on;wide area network composed of 2G/3G/4G.In response to the problem of wireless communication technology for the Internet of Things,low-power Wide-Area network(LPWAN)technology represented by LoRa technology has emerged,LoRa technology has the characteristics of long distance,low power consumption,and has the opportunity to break the bottleneck of the traditional traditional internet wireless transmission technology.This paper first introduces the development history of several traditional wireless communication technology and their characteristics,then it introduces the basic principle of LoRa technology.A long-distance and long-power consumption wireless sensor network terminal node is designed based on LoRa technology.Including the hardware design of the node:series microprocessor based on STM8,SX1278 Series RF chip produced by Semtech,wireless sensor network terminal node integrating various sensors and battery power supply modes;software design:including sensor data acquisition,microprocessor data processing,and RF transmission and reception,low power consumption management of the node;finally,functional tests and performance tests were performed on the wireless sensor network terminal nodes to verify that the designed wireless sensor network terminal nodes have long-distance,low-power operating characteristics.When the communication distance is less than 1km,the PER is less than 5%;when the communication distance is less than 3.5km,the PER is less than 30%;If the terminal node is set to wake up once every minute,the average current is only 0.712 mA,the battery can theoretically work for terminal nodes for 537 days.Finally,a localization algorithm using K-means clustering is proposed for the outdoor localization application of the terminal node.Compared with the traditional RSSI ranging-based localization algorithm,the accuracy is improved.