UDP multi connection mode under at instruction of ESP module

Ready to work

Prepare an ESP-F module of the DOITING brand or NODEMCU of the DOIT brand.

![|554x554](file:///C:\Users\Administrator\AppData\Local\Temp\ksohtml12944\wps5.png)

That is, VCC, EN connection 3.3v, GPIO15 GND grounding, module TX, RX connection serial port tool RX, TX, RST pin low level reset, unnecessary IO pin can be suspended, if you want to download the firmware in the module, please pull GPIO0 down processing (warm hint: if you buy ESP-01S/M/F1/F2, only need to connect VCC GND RX TX can work normally). If you buy an ESP-01 module, just connect CH-PD to VCC. Others can be connected according to the figure below (no IO port can not be connected). Please refer to the following instructions for product hardware design circuit.

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1. 2 . Test

After completing the 1.1 connection, please check the circuit in detail and confirm that there is no problem. Open the debugging aid of serial port. The configuration mode is baud rate: 115200, data bit: 8 check bit: none stop bit: one flow control: none.

The configuration information is as follows:

To confirm that there is no problem, please press the RST reset key of K1 button (low level about 300m). Print the information as follows:

Display “read” to prove that the startup is normal.

Common Tools Download Connection:

![\ 469x269](file:///C:\Users\Administrator\AppData\Local\Temp\ksohtml12944\wps7.jpg)

Frequently problems:

  1. Keyboard does not reflect

(1) Please check whether the power supply of the module is 3.3V/800ma.

(2) Please check whether TX and RX are in the wrong place.

(3) Check whether the port number is selected correctly and whether the port of serial debugging assistant is closed.

  1. The keys are all scrambled.

(1) Please confirm the baud rate of the module with the module manufacturer.

(2) Please check whether USB to TTL is compatible with module communication. What is recommended is a USB to TTL made of CH340 and CP2102 chips?

(3) Make sure that there is something wrong with the program in the module. (I’ll talk about how to burn firmware for modules later.)

module UDP multi-connection mode

AT + CWMODE = 1 Set STA mode (serial port assistant)

AT + CWLAP query nearby WIFI (serial port assistant)

AT + CWJAP = “123123”, “12345678” Connect to WIFI (serial port assistant)

AT + CIFSR View the current IP of the module. (Serial Assistant)

AT + CIPMUX = 1 open the module multi-connection (serial port assistant)

Network debugging assistant: Connect the computer to the router, open the network debugging assistant, and configure the UDP sending and receiving ports as shown below: (The network debugging assistant can be set in advance)

AT + CIPSTART = 0, “UDP”, “255.255.255.255”, 50000,1000, 0 is to establish a UDP connection, where the mobile phone UDP server is set to 50000 and the UDP client is set to port 1000

AT + CIPSEND = 0, 11 module send data mode is 9 bytes

Enter send data mode

www.doit.am send data

Network debugging assistant sends data: Shenzhen Sibo Zhilian Technology Co., Ltd. (Network debugging assistant)

Note: Multiple network debugging assistants can be used to send data to the module. Note: local host port, target host and port number.

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![|554x523](file:///C:\Users\Administrator\AppData\Local\Temp\ksohtml12944\wps9.jpg)