The content of Guyueju primarily focuses on ROS, but we should not limit ourselves to software; we must also improve our hardware learning. Therefore, today I am opening a new project to learn about the ESP8266 step by step, and I will share some interesting projects I completed recently.
Here, I would like to thank Guyueju for giving me this opportunity to share with everyone.
Here we mainly use the ESP8266EX chip, which has a complete and self-contained Wi-Fi network functionality, capable of independent application as well as being used as a slave to run on other host MCUs.
The ESP8266EX integrates antenna switches, RF balun, power amplifiers, low-noise amplifiers, filters, and power management modules. This compact design requires very few external circuits and minimizes the PCB size.
Illustration: ESP8266EX Package: QFN32
The ESP8266EX was developed by Espressif Systems, and the ESP8266 module was also developed by Espressif Systems.
The ESP8266 module was developed by Aoxin Technology based on the ESP8266EX and optimizes the layout of peripheral devices and antennas, making it convenient for developers to conduct secondary development.
Supports 802.11 b/g/n (HT20)
802.11a/b/g/n refers to wireless network protocols, divided into 802.11a, 802.11b, 802.11g, 802.11n, etc. These different wireless protocols have evolved from 802.11.
What does HT20 represent?
11n has two bandwidth modes: HT (High Throughput) 20 and HT 40.
HT20 refers to a 20M bandwidth in the network, while HT40 refers to a 40M bandwidth in the network.
HT20 is set for compatibility considerations: for example, if only 802.11b/g signals exist in an area, to minimize interference, it needs to be set to HT20 to reduce frequency overlap.
HT40 is set for high performance: HT40 binds two adjacent 20MHz channels together to form a 40MHz channel, one as the primary and the other as the secondary. The primary channel sends beacon messages and some data messages, while the secondary channel sends other messages.
802.11 n (2.4 GHz), speeds up to 72.2 Mbps
Here I would like to make a note for Mbps:
Mbps is equivalent to Mbit/s
Based on this conversion, the official maximum speed is 9MB/s
Reassembly (defragmentation)
2 x Virtual Wi-Fi Interfaces
Virtual Wi-Fi is equivalent to a hotspot, allowing the creation of a separate network for other devices.
Beacon Automatic Monitoring (hardware TSF)
Supports Infrastructure Network (Infrastructure BSS) Station Mode/SoftAP Mode/Mixed Mode
(1) SoftAP Mode (Soft Router Mode)
(2) Station Mode (Client Mode)
(3) SoftAP + Station Coexistence Mode (Mixed Mode)
Reasons for Choosing ESP8266
The ESP8266 chip costs about 5 RMB, while the module costs about 10 RMB. Some stores on Taobao sell ESP modules at very low prices; I previously bought an ESP-12F for 5 RMB each. At such a low price, who needs a bicycle?
Generally, Wi-Fi transmission distances are around 100 meters. However, a previous article published on Espressif’s official WeChat account titled “How Far Can ESP8266 Wi-Fi Transmit” shared a testing video from Germany’s AReResearch using the NodeMCU development board, showing that in open areas, reliable connections can be maintained within 300 meters, while signal loss occurs beyond 400 meters.
This testing video has circulated widely online, greatly increasing the awareness of the ESP8266, even among those who have never heard of or purchased it.
3. Convenient Development Environment
There are many development environments for the ESP8266 SDK. The official development environment setup is relatively complex, but the integrated development environment ESP8266 IDE 2.0, produced by the solution provider Aoxin, makes it much easier to get started. Later, Arduino IDE also supported ESP8266 (I use VScode for ESP8266 development; I will explain why next time).
On the other hand, the support for development languages is rich:
The NodeMCU project allows the use of Lua to develop ESP8266 control programs.
The MicroPython project allows the use of Python to develop ESP8266 control programs.
The Smart.js project allows the use of Java to develop ESP8266 control programs.
Forth, LISP, Apple BASIC······
This further lowers the development threshold, allowing more software personnel to join this industry.
Various suppliers have launched ESP8266 modules and boards, making applications quicker. For example, Aoxin has launched a series of ESP8266 modules with different functionalities, Seeed Studio’s Wio Link, and various ESP8266 development boards (such as NodeMCU, etc.) from different solution providers. Internationally renowned maker suppliers like Adafruit and SparkFun have also released ESP8266 boards. Not to mention the many self-made ESP8266 modules and development boards.
5. Very Active Developer Community
Both official and unofficial developer communities are very active in sharing and discussing, which is evidenced by their rich development resources. Espressif can gather more user needs through this active community and develop better products (the newly released ESP32 Wi-Fi + Bluetooth dual-mode chip has created a stir in the industry).
This chapter serves as the introductory chapter for ESP8266, and I aim to provide everyone with rich knowledge and practical experience.I hope to contribute to the ESP8266 community.Next, let us step into the world of ESP8266 based on Arduino development.
The Guyueju website has launched a forum function (guyuehome.com/forums), and everyone is welcome to ask questions and communicate in various sections. The next person to be replied to by Guyuejun could be you~
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