This article is an excellent piece from the KX Forum Author ID on KX Forum: xiaoduoduo himqtt is the first complete source high-performance MQTT IoT firewall – MQTT Application FireWall, written in C language, using epoll mode to support hundreds of thousands of high concurrent connections for IoT, and is compatible with some ModSecurity rules. … Read more
Let’s look at this scenario: You have a temperature sensor that publishes the current temperature to a Topic every three hours. So the question arises, if a new subscriber subscribes to this topic right after it has published the current temperature, when will this subscriber receive the temperature message? That’s right, it has to wait … Read more
In recent days, I have been preparing for the follow-up IoT STM32 development and practical demonstrations, as well as writing mini-programs, so I haven’t had time to update the articles on my public account. Actually, I originally planned to wrap up the series of articles about the IoT platform with the last one. However, a … Read more
Click on the “Embedded Application Research Institute” above, and select “Top/Star Official Account“ Useful Resources Delivered First Hand! Source | Embedded Application Research Institute Compiled & Formatted | Embedded Application Research Institute In the development of IoT-related applications, MQTT is used to some extent. The following open-source project is an interface I encapsulated based on … Read more
Background Keep alive is part of the variable header in the CONNECT message. We have mentioned that the Broker needs to know whether the Client has disconnected abnormally to send the last will message. In fact, the Client also needs to quickly detect if it has lost the connection to the Broker in order to … Read more
1. Review: Overview of ROS Communication Mechanism & Similarities and Differences with MQTT Communication Overview of ROS Communication Mechanism The main communication mechanisms in ROS are as follows: 1. Topics ○ Publish/Subscribe Model: In this communication method, nodes can publish messages to a topic or subscribe to a topic to receive messages. This method is … Read more
Introduction: The First Groundbreaking Product to Introduce QUIC to MQTT In the recently released version 5.0, EMQX has innovatively introduced QUIC support. QUIC is the underlying transport protocol for the next-generation internet protocol HTTP/3. Compared to TCP/TLS protocols, it effectively reduces connection overhead and message latency, providing a flexible and efficient transport layer for modern … Read more
Background Previously, we discussed how to publish messages and their corresponding packets; now let’s look at how the packets for subscribing to a topic are structured. SUBSCRIBE – Subscribe to a Topic The client sends a SUBSCRIBE packet to the server to create one or more subscriptions. Each subscription registers one or more topics of … Read more
Author：Nanhai District Dali Town Junior High School, Foshan City, Guangdong Province Zhang Quan, Ling Yujie, Xie Hanzhe This article is sourced from “Invention and Innovation” May 2023 Junior High School Edition We found that homeroom teachers and subject teachers have many repetitive and mechanical tasks, such as: every day the homeroom teacher conveys messages from … Read more
Data packets sent by IoT smart devices must be encapsulated by the corresponding protocol at each layer. With the rapid development of Internet of Things (IoT) technology, most smart devices’ communication modules support various network communication protocols such as TCP, UDP, MQTT, CoAP, HTTP, and LwM2M, which include both transport layer and application layer protocols, … Read more