The Design And Implementation Of Civil Air Defence Command Post Edge Controller Based On MQTT

The civil air defence command post controller is responsible for monitoring and controlling devices such as electric gate,fan,valve and diesel generator in the civil air defence command post,which is the foundation of field facility network and the source of data generation in the civil air defence command post.Traditional air defence command post controller leads the network to use hierarchy and protocol more,with limited data transmission bandwidth,inconvenient network expansion and other shortcomings.To solve above shortcomings,this paper studies the edge controller of civil air defence command post based on MQTT,which upgrades the traditional air defence command post controller and makes it possible to monitor the civil air defence command post on a larger scale.The study lays a foundation for the application of edge computing,artificial intelligence and other technologies in air defence command post.The topic has important theoretical significance and practical value.Based on investigation of the traditional civil air defence command post controller and new Internet of things protocols,this paper analyzes the advantages of using MQTT protocol and proposes an Internet of things architecture for the civil air defence command post based on MQTT.STM32 MCU is used as the edge controller master control chip.The transplantation of embedded operating system FreeRTOS and embedded TCP/IP stack LWIP in STM32 is studied and implemented.The MQTT client,IO function board and Modbus device monitoring,business logic and configuration functions of the edge controller are designed and implemented.The design also improves reliability of the edge controller network and I~2C bus.At the end of the paper,the edge controller of the civil air defence command post is tested from perspectives of reliability,upload speed and issuing speed.The test results show that the edge controller based on MQTT has certain reliability and the speed of uploading and responding to instructions is at the millisecond level,which can realize the real-time state detection and control of civil air defence field facility.