Hello everyone, this article introduces the MQTT protocol and how to use the MQTT client and develop it in the OpenWrt system, along with relevant example code. Introduction to MQTT MQTT (Message Queuing Telemetry Transport) is a lightweight communication protocol designed for transmitting messages in low bandwidth and unstable network environments. It was originally developed … Read more
The MQTT protocol, which stands for Message Queuing Telemetry Transport, is a lightweight messaging protocol based on the publish/subscribe model, designed for the Internet of Things. Here’s a detailed introduction: Protocol Basics Protocol Overview: MQTT was originally developed by IBM to provide a simple and efficient messaging communication method for resource-constrained devices and low-bandwidth, high-latency … Read more
The previous two articles discussed the basic decomposition process of the MQTT protocol. This chapter mainly discusses the implementation of specific messages. Since the message handling specifications are quite similar, we will introduce the Connect and Publish messages, which are relatively complex in the MQTT protocol. Understanding the protocol analysis of these two messages will … Read more
This article is an excellent piece from the Kanxue forum. Author from Kanxue forumID: emqttx With the arrival of the 5G era, the grand vision of the Internet of Things (IoT) is becoming a reality. The number of connected IoT devices reached 7 billion in 2018[^1], and in the next two years, the number of … Read more
Click the blue text to follow us 1. Overview of EtherCAT 1. Features ① Open Technology EtherCAT, short for EtherNet Control Automation Technology, is a real-time Ethernet technology proposed by Beckhoff Automation in Germany. EtherCAT is an open but not open-source technology, meaning you can use this technology freely, but you need to obtain relevant … Read more
【Introduction】The compatible and open EtherCAT technology has been validated by 20 years of practical experience. Why is EtherCAT considered the best choice for engineers? For more information about HARTING products, please click at the bottom of the article“Read the original text”to get it Technical communication, click here to join the group Sales and procurement, click … Read more
When it comes to short-range IoT technologies, besides Wi-Fi and Bluetooth, there is actually another well-known player—ZigBee. ZigBee has been one of the important wireless communication protocols in recent years, widely used in the IoT field, especially in smart home applications. Today, let’s take a detailed look at it! 1. Origin and History 1Why Was … Read more
In practical control projects centered around PLCs, most cases rely on the cooperation of touch screens or upper-level computers. This is because we use PLCs for control, primarily dealing with some analog quantities, which are the values we need to monitor, such as pressure, temperature, and flow on the equipment. These detected values are then … Read more
Limited Time Offer | 5 Essential Books for Electricians (ClickBlue Words, to get free materials↑↑) In practical control projects centered around PLCs, we often rely on touch screens or upper computers. This is because we use PLCs for control, primarily to process some analog signals, which are the values we need to monitor, such as … Read more
1. Introduction As shown in the figure below, this four-channel HDMI video switch controller has been used during the video recording process in my laboratory. It can be controlled via the front panel buttons or by sending commands over the network. To facilitate remote control on the experimental platform, I plan to use this wireless … Read more