Single connection

(ESP8266 as TCP client)

1. Set wifi mode：
   AT+CWMODE=3 // softAP+station mode
   Response：OK
   
2. Reboot to take effect:
   AT+RST
   Response：OK
   
3. Connect to router
   AT+CWJAP="ssid","password" // ssid and password of router
   Response：OK
   
4. Query device’s IP
   AT+CIFSR
   Response：192.168.3.106 // Device got an IP from router.
   
5. Using a network tool (eg: ”NetAssist.exe”) on the computer to create a server.
   For example, server ip address:192.168.3.116, port 8080
   
6. ESP8266EX connect to server as a client
   AT+CIPSTART="TCP","192.168.3.116",8080 //protocol、server IP & port
   Response：OK
   
7. Send data
   AT+CIPSEND=4 // set date length which will be sent, such as 4 bytes
   >DGFY // enter the data, no CR
   Response：SEND OK
   Note: If the number of bytes sent is bigger than the size defined (n), will reply busy, and after sending n number of bytes, reply SEND OK.
   
8. Receive data:
   +IPD,n:xxxxxxxxxx // received n bytes, data=xxxxxxxxxxx
   

Transparent transmission

1. Set wifi mode：
   AT+CWMODE=3 // softAP+station mode
   Response：OK
   
2. Connect to router
   AT+CWJAP="ssid","password" // ssid and password of router
   Response：OK
   
3. Query device’s IP
   AT+CIFSR
   Response：192.168.101.105 // Device’s ip that got from router.
   
4. Using a network tool (eg: ”NetAssist.exe”) on the computer to create a server.
   For example, server ip address:192.168.101.110, port 8080
   
5. Device connect to server
   AT+CIPSTART="TCP","192.168.101.110",8080 // protocol、server IP & port
   Response：OK
   Linked
   
6. Enable transparent transmission mode
   AT+CIPMODE=1
   Response：OK
   
7. Start send
   AT+CIPSEND
   Response： >
   Note: From now on, data received from uart will be transparent transmited to server.
   
8. Stop send
   Data packet contains only “+++” exits Unvarnished transmission.
   

Multiple connection

(ESP8266 as TCP server)

1. Set wifi mode：
   AT+CWMODE=3 // softAP+station mode
   Response：OK
   
2. Enable multiple connection
   AT+CIPMUX=1
   Response：OK
   
3. Setup server
   AT+CIPSERVER=1 // default port = 333
   Response：OK
   
4. PC connects to ESP8266EX softAP as station, then PC connects to ESP8266EX server as client.
   NOTE: ESP8266EX acting as server has a timeout mechanism. When connection is established and no data is transmitted within a period of time, it will disconnect the client. Please setup a recurring packet transmission every 5s on the computer to ensure connection is maintained.
   
5. Send data
   AT+CIPSEND=4 // set date length which will be sent, such as 4 bytes
   >iopd // enter the data, no CR
   Response：SEND OK
   Note: If the number of bytes sent is bigger than the size defined (n), will reply busy, and after sending n number of bytes, reply SEND OK.
   
6. Receive data: +IPD,n:xxxxxxxxxx // received n bytes, data = xxxxxxxxxx
   

UDP transmission

1. Set wifi mode：
   AT+CWMODE=3 // softAP+station mode
   Response：OK
   
2. Connect to router
   AT+CWJAP="ssid","password" // ssid and password of router
   Response：OK
   
3. Query device’s IP
   AT+CIFSR
   Response：+CIFSR:STAIP,"192.168.101.104" // IP address of ESP8266 station
   
4. PC connects to the same router which ESP8266 connects to. Using a network tool (eg: ”NetAssist.exe”) on the computer to create UDP .
   
5. Enable multiple connection
   AT+CIPMUX=1
   Response：OK
   
6. Create a UDP transmission, for example, id is 4.
   AT+CIPSTART=4,"UDP","192.168.101.110",8080,1112,0
   Response：4,CONNECT OK
   Note：
   "192.168.101.110",8080 here is the remote ip and port of UDP transmission which create on PC in step 4;
   1112 is the local port of ESP8266, user-define, if user does not define it, it will be a random value;
   0 means destination peer entity of UDP will not change. For example, in this case, if another PC also creates a UDP entity and sends data to ESP8266 port 1112, ESP8266 can receive these data, but when we send data with command “AT+CIPSEND=4,X”, it will still be sent to the first PC. If this parameter is not 0, it will send to the new PC.
7. Send data
   AT+CIPSEND=4,5 // Send 5 bytes to transmission NO.4
   Response > DGFYQ // enter the data, no CR
   SEND OK
   Note: If the number of bytes sent is bigger than the size defined (n), will reply busy, and after sending n number of bytes, reply SEND OK.
   
8. Receive data:
   +IPD,4,n:xxxxxxxxxx // received n bytes, data=xxxxxxxxxxx
   
9. Delete transmission NO.4
   AT+CIPCLOSE=4
   Response：4,CLOSED OK