| Wireless communication technology is a key technology in the development of IoT(Internet of Things,IoT),ZigBeeisawireless communication technology,because of its short distance,low power consumption,low cost,low complexity,high reliability and many other advantages are widely used in smart home,intelligent agriculture,automation industry and so on.ZigBee node is an important role in the perception layer of IoT,which is responsible for the information collection,automatic control and other important functions.With a large number of ZigBee nodes being invested into the Internet of Things industry,the massive ZigBee nodes firmware upgrade becomes an important issue.The traditional firmware upgrade scheme of ZigBee node includes two steps: firstly,the nodes are recalimed,secondly,the wired connection is used for the firmware upgrade,but when it is used in the IoT industry with massive ZigBee nodes,the cost of the firmware upgrade greatly increase because of the difficulty of ZigBee node recovery,and the upgrade efficiency becomes extremely low.Therefore,the firmware update of ZigBee node is worth to be studied deeply.According to the OTA(Over The Air)air upgrade technical specifications which is proposed by ZigBee alliance,TI company,achieves the ZigBee node OTA technology in the Z-Stack protocol stack,but there are still many problems in the the OTA technology,such as the inefficiencies problem of firmware upgrade.In this thesis,the problem of low efficiency of OTA technology is studied deeply,and is proposed and realized the maximum image page upgrade scheme,multi-node concurrent upgrade scheme based on the tree network,at last,the improved OTA technology is applied to the actual project and a series of tests are carried out.The work done in this thesisis as follows:1)The comparison and analysis are made between ISP and IAP firmware upgrade technology,and the working principle of ZigBee protocol OTA technology is analyzed;2)The problem of the upgrade way of image block and the collision problem which is caused in the process of multi node simultaneous upgrade are analyzed.Aiming at the problem of upgrading efficiency,the original scheme is optimized and the improved scheme is realized,and experiments are madeto verify the feasibility of the improved scheme;3)The problem of the OTA broadcast upgradein the ZigBeetreenetwork,and the improved scheme is designed and realized based on the workload of the OTA Server node;4)The improved multi-node concurrent updatescheme isapplied to the actual project,and the firmware transmission experiments aremadein the tree ZigBee network atdifferent depths in order to test the transmission efficiency of theimproved scheme.From the tests,the improved OTA technology in this thesisshowes that it can solve the existing problems,not only can enhance the efficiency of single ZigBee node upgrade,but also can enhance the efficiency of multi node broadcasts upgrade.And it can effectively reduce the workload of the OTA Server node. |
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