Hi-Link has been established for 12 years. Now Hi-Link provides many product lines covering the Internet of Things, such as communication modules, sensor modules, power modules, and product applications. Among them, the WiFi routing module has always been Hi-Link. Branch's pillar products.

In this article, Hi-Link will provide a concentrated technical answer to the common sense questions of the WiFi module. Those who are interested can continue to browse. Hi-Link Official WeChat: HLKtech09

Take Hi-Link HLK-RM04 wireless routing module as an example. The HLK-RM04 module is one of Hi-Link's classic best-selling products. It has a built-in TCP/IP protocol stack and can realize 3 interfaces of user serial port, Ethernet and wireless network. Any conversion between it is a low-cost embedded UART-ETH-WiFi module.

1.

Question:What is the serial WiFi module?

Hi-Link: In layman's terms, we can understand it as a converter, which converts the serial port signal of the single-chip microcomputer into a wireless WiFi signal, also known as the serial port to WiFi module.

2.

Question:How many ways does the serial WiFi module work?

Hi-Link: There are two ways of working, namely transparent transmission mode and command mode. In the transparent transmission mode, no matter what data is sent to the module, the module will not process it (except for the relevant instructions to exit the transparent transmission mode), but directly encapsulate the data and send it. Command mode generally refers to the AT command operation mode, and its format is generally (AT+CMD).

3.

Question:How does the serial WiFi module work?

Hi-Link: Working principle: network sending-TCP data => module => serial port data-MCU receiving, the reverse is the same, the module is only a transmission channel.

4.

Question: What are the working modes of the serial port WiFi module?

Hi-Link: Its working modes are STA and AP respectively. STA is the site mode and the client mode, which is the same as connecting the router to our computer, which is equivalent to the role of the computer. AP is a hotspot, which means that it can radiate a wireless WiFi network as an AP mode. To put it simply, it is to extend the wired network to a wireless network. If an AP is connected to the wired network, then mobile phones and laptops You can use the wireless network.

5.

Question: How to switch between transparent transmission mode and command mode?

Hi-Link: Switch the command mode to transparent transmission mode through AT+Z or power on the WiFi module again, switch the transparent transmission mode to command mode, send +++ through the serial port (there are only three +), the WiFi module returns + OK, indicating that the WiFi module has entered the command mode.

6.

Question: Can the serial WiFi module be remotely controlled?

Hi-Link: The serial WiFi module can be remotely controlled, but it must be built on the basis of a server. Because the IP address of the WiFi module is not connected to the external network, and its IP address is an internal network address, that is to say, the IP of the WiFi module cannot be found in the external network server, and it cannot be provided with the data forwarding function.

7.

Question: What is the difference between TCP protocol and UDP protocol in network communication?

Hi-Link: The TCP protocol is a reliable protocol. A three-way handshake must be established during the communication process, and the client initiates a TCP connection during the communication process. The UDP protocol is the broadcast protocol we are familiar with. It is an unreliable communication protocol and is generally used to find the IP of a certain device in network communication.

8.

Question:What do I need to realize the mobile phone control MCU?

Hi-Link: Prepare in advance: MCU, mobile phone APP, WiFi module and related MCU peripheral circuits and devices. Control process: The MCU of the single-chip microcomputer sends data to the serial WiFi module through the serial port, and finally the wireless data of the WiFi module is forwarded to the mobile phone.

Hi-Link has been established for 12 years and has accumulated a wealth of industry experience. Friends with any IoT module needs can contact Hi-Link. In the new year, Hi-Link will have more new products in the industry. Welcome to continue to pay attention to us.