Learn about the Internet of things protocol WiFi ZigBee Bluetooth, etc. --- WiFi and WiFi protocols start from WiFi. What do we need to know about WiFi protocol itself?

11 Introduction to Internet of things protocols , Such as WiFi、 bluetooth 、ZigBee、 Honeycomb, etc 】

11 Introduction to Internet of things protocols , Such as WiFi、 bluetooth 、ZigBee、 Honeycomb, etc 】

WIFI Basic knowledge arrangement ----- Good article

wiif Wireless fidelity —Wireless Fidelity

WIreless-FIdelity– Wireless fidelity -- Radio frequency radio electromagnetic wave

WiFi Connectivity is often an obvious choice for many developers , Especially considering the home environment within the LAN WiFi The popularity of . In addition to clearly stating , The existing infrastructure is extensive , And provide fast data transmission and the ability to process a large amount of data , This requires no further explanation .

at present , The most common used in families and many businesses WiFi The standard is 802．11n, It provides a strict throughput of hundreds of megabits per second , This is good for file transfer , But for many IoT It may be too power consuming for applications . RS Provides a series of tools for building WiFi Of application RF Development Kit .

standard ： be based on 802．11n（ The most common use today ）

frequency ：2．4GHz and 5GHz Frequency band

Range ： about 50m

Data rate ： Maximum 600 Mbps, But according to the channel frequency and the number of antennas used （ Abreast of the times 802．11－ac The standard should provide 500Mbps to 1Gbps）,150－200Mbps More typical .

wifi Detailed explanation （ One ）
wan Full name Wide Area Network, It means wide area network ;lan Full name Local Area Network, It means LAN
WLAN It's English WirelessLAN Abbreviation , It means wireless LAN . Wireless Ethernet technology is a LAN technology based on wireless transmission , Compared with wired network technology , Have flexibility 、 Build the network quickly 、 Personalization and other characteristics . Apply this technology to the access network field of telecommunication network , Convenient 、 Flexibly provide users with network access , Suitable for users with high mobility 、 Public places with data business needs 、 High end enterprise and household users 、 Occasions requiring temporary network construction and environments that are difficult to adopt wired access .

Link to the original text ：https://blog.csdn.net/ylyuanlu/article/details/7711396

Wifi Transplantation analysis

One 、openssl Transplantation
Two 、wpa_suplicant transplant
3、 ... and 、 load insmod rt8192cu.ko Drive to the development board .
Four 、wifi Test of
Wifi Transplantation analysis

How to use it in actual projects wifi— Data link layer and physical layer

wifi The protocol defines the frame type — Data link layer
802.11 Three types of frames ：
Manage frames
Control frame
Data frame

Yes WiFi modular , If you can use modules OK Did you? ？？？

About wifi The agreement itself, we need to know those things ？？？

kankan

stm32 Implement a simple wifi signal communication
Test routine

AT Instruction Introduction
AT（Attention） The order is made by Dennis Hayes Invented , So it's also called Hayes command set.AT Instructions were originally intended to guide modem Working , Later, with the development of Technology , low speed modem It has been withdrawn from the market , but AT Instructions continue to develop , And today AT Instructions still play a very important role .

Although in PC End 、 There is no more on the mobile phone AT Use , However, it plays an important role in various networking modules in the embedded industry , And it is not only applied to cellular modules , It is also applied to WiFi、BLE And so on .

current AT Instructions are mainly applied to cellular modules 、WiFi modular 、BLE Module , The purpose is to simplify the complexity of embedded device networking .
Link to the original text ：https://blog.csdn.net/u012349679/article/details/112559324