Research And Implementation Of Wide-area IoT Technology Based On LoRaWan

In recent years,the technology of IoT is developing fast,but for some engineering sites in remote areas,such as dam and hydrological monitoring of the river,because of no network,no electricity,and the high cost of the mobile network,restricted by the technology of IoT,some IoT project can not be implemented.For the engineering problem,combined with the low cost,the low power consumption,and the wide range wireless communication network of LoRa technology,this paper proposes a IoT solution based on LoRaWan to breakthrough the bottlenecks of traditional IoT technology in power and communication distance?Based on the network structure of LoRaWan protocol,this paper focuses on the LoRa gateway node.The gateway node mainly plays two roles in the LoRaWan IoT system,one is to be like a network relay,and transmit data between each gateway node and terminal node.The second is to complete the conversion of data and converts the data of LoRaWan format into other formats,such as serial data and send it to the server.The main contents of the thesis include three points: firstly,completing the gateway device hardware selection,and the overall design framework.Considering power dissipation of the gateaway device,selecting the microchip company's PIC24 series chips as MCU,Rechargeable Lithium polymer Battery as power supply,and choosing Semtech company's SX1278 chip as a radio to reach the requirement of long distance communication.Secondly,the software function of LoRa gateway is designed and realized.LoRa gateway software is mainly divided into three types,the underlying driver software used to realize various hardware basic functions,the Bootloader software used to initialize each module and load other applications,and the gateway application software that realize the configuration of gateway equipment and data transmission.Thirdly,based on the accomplishment of the software and hardware of the LoRaWan gateway node,the current and voltage of the hardware interface and the basic function of the software design are tested,and the gateway equipment is deployed to a project field to conduct the test of the rate of communication,the packet loss rate and the distance of communication.The LoRaWan IoT system designed in this paper is deployed in one hydropower station,to test the transmission distance and the transmission speed;.Through analyzing the collected test data,the data integrity,rate and transmission distance of the equipment are found to meet the expected requirements.