EPS - ESP communication via TCP/IP

[Miksior]

Hello everyone!

I am looking for an example/guide how to use TCP/IP protocol to set up connection between few ESP modules.

So far i prepared UDP communication between 3 esp modules and it works, now i am looking for TCP/IP example. I would be grateful if u could help me and show me the example/code of TCP/IP implementation!

Regards!

[Thomas_01]

Hallo,
I'm interested in the UDP-example. Can you write the program (the UDP parts) here in the forum.

thank you
Thomas

[Miksior]

Sure: here you have the code:

Server :

Code: [Select all] [Expand/Collapse]

1. #include <ESP8266WiFi.h>
2. #include <WiFiUdp.h>
3.  
4. WiFiUDP Udp;
5. unsigned int localUdpPort = 4210;  // local port to listen on
6. char incomingPacket[255];
7. IPAddress ip(192, 168, 4, 1);
8.  
9. void setup()
10. {
11.   Serial.begin(115200);
12.   Serial.println();
13.  
14.   WiFi.begin("ESP32", "123456789");
15.  
16.   Serial.print("Connecting");
17.   while (WiFi.status() != WL_CONNECTED)
18.   {
19.     delay(500);
20.     Serial.print(".");
21.   }
22.   Serial.println();
23.  
24.   Serial.print("Connected, IP address: ");
25.   Serial.println(WiFi.localIP());
26. }
27.  
28. void loop() {
29.  
30. while (WiFi.status() != WL_CONNECTED)
31. {
32.   WiFi.reconnect();
33.   delay(10000);
34.   Serial.print(".Reconnected");
35.   Serial.println(WiFi.localIP());
36. }
37. Udp.beginPacket(ip, localUdpPort);
38. Udp.write("45"); // wysyłamy jeden bajt
39. Udp.endPacket();
40. Serial.print("Wyslalem cos\n");
41. delay(5000);
42. }
43. }

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and the client:

Code: [Select all] [Expand/Collapse]

1. #include <WiFi.h>
2. #include <WiFiClient.h>
3. #include <WiFiAP.h>
4. #include <WiFiUdp.h>
5. #include <stdlib.h>
6.  
7. WiFiUDP Udp;
8. unsigned int localUdpPort = 4210;  // local port to listen on
9. char incomingPacket[255];  // buffer for incoming packets
10.  
11.  
12. void setup()
13. {
14.   Serial.begin(115200);
15.   Serial.println();
16.  
17.   Serial.print("Setting soft-AP ... ");
18.   Serial.println(WiFi.softAP("ESP32", "123456789") ? "Ready" : "Failed!");
19.   IPAddress myIP = WiFi.softAPIP();
20.   Serial.print("AP IP address: ");
21.   Serial.println(myIP);
22.  
23.  
24.   Udp.begin(localUdpPort);
25.   Serial.printf("Now listening at IP %s, UDP port %d\n", WiFi.localIP().toString().c_str(), localUdpPort);
26. }
27.  
28. void loop()
29. {
30.   int packetSize = Udp.parsePacket();
31.   if (packetSize)
32.   {
33.     // receive incoming UDP packets
34.     Serial.printf("Received %d bytes from %s, port %d\n", packetSize, Udp.remoteIP().toString().c_str(), Udp.remotePort());
35.     int len = Udp.read(incomingPacket, 255);
36.     if (len > 0)
37.     {
38.       incomingPacket[len] = 0;
39.     }
40.     Serial.printf("UDP packet contents: %s\n", incomingPacket);
41.   }
42. }

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[Thomas_01]

Hallo,

thank you for your post.
I have never worked before with UDP directly. I see your code so: The server sends and the client receives one Byte.
This is a communication in one direction. For two-way communication I have to mix client and server without the long delay() at the end of the server-loop...

I will try it and talk about my results here.


bye
Thomas