Connect two Mega together with ethernet Shield

Hello every one !

I'm new in arduino world and i need your help !

I'm C# and PLC programmer, but i need to work on arduino for my compagny.

I have two Arduino MEGA and two ethernet shields :
(Shield Ethernet EF02029 Elecfreaks - Articles retires | GO TRONIC)

I try to make communicate one with the other one.
EDIT : My goal is : Send digital and analogique signal from client to server.

I have try the sample exemple code (WebServer and WebClient), i have change the MAC adress because they are the same in the example, affect IP adresse, remove the DHCP part... i can see the TX led on my client arduino, but didnt have the RX led on the server arduino.. I use a straight RJ45 cable..is that ok?

Did you have any advice for me or snipped could help me?

Thank you in advance and sorry for my english (i'm french).

Best regards.

Ludo

Server :

/*
  Web Server

 A simple web server that shows the value of the analog input pins.
 using an Arduino Wiznet Ethernet shield.

 Circuit:
 * Ethernet shield attached to pins 10, 11, 12, 13
 * Analog inputs attached to pins A0 through A5 (optional)

 created 18 Dec 2009
 by David A. Mellis
 modified 9 Apr 2012
 by Tom Igoe
 modified 02 Sept 2015
 by Arturo Guadalupi
 
 */

#include <SPI.h>
#include <Ethernet.h>

// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
  0x90, 0xa2, 0xda, 0x00, 0x23, 0x16
};
IPAddress ip(192, 168, 1, 177);

// Initialize the Ethernet server library
// with the IP address and port you want to use
// (port 80 is default for HTTP):
EthernetServer server(80);

void setup() {
  // You can use Ethernet.init(pin) to configure the CS pin
  //Ethernet.init(10);  // Most Arduino shields
  //Ethernet.init(5);   // MKR ETH shield
  //Ethernet.init(0);   // Teensy 2.0
  //Ethernet.init(20);  // Teensy++ 2.0
  //Ethernet.init(15);  // ESP8266 with Adafruit Featherwing Ethernet
  //Ethernet.init(33);  // ESP32 with Adafruit Featherwing Ethernet

  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  Serial.println("Ethernet WebServer Example");

  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);

  // Check for Ethernet hardware present
  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
    while (true) {
      delay(1); // do nothing, no point running without Ethernet hardware
    }
  }
  if (Ethernet.linkStatus() == LinkOFF) {
    Serial.println("Ethernet cable is not connected.");
  }

  // start the server
  server.begin();
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
}

void loop() {
  // listen for incoming clients
  EthernetClient client = server.available();
  if (client) {
    Serial.println("new client");
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        Serial.write(c);
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the http request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          // send a standard http response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connection: close");  // the connection will be closed after completion of the response
          client.println("Refresh: 5");  // refresh the page automatically every 5 sec
          client.println();
          client.println("<!DOCTYPE HTML>");
          client.println("<html>");
          // output the value of each analog input pin
          for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
            int sensorReading = analogRead(analogChannel);
            client.print("analog input ");
            client.print(analogChannel);
            client.print(" is ");
            client.print(sensorReading);
            client.println("
");
          }
          client.println("</html>");
          break;
        }
        if (c == '\n') {
          // you're starting a new line
          currentLineIsBlank = true;
        } else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    // give the web browser time to receive the data
    delay(1);
    // close the connection:
    client.stop();
    Serial.println("client disconnected");
  }
}

Client :

/*
  Web client

 This sketch connects to a website (http://www.google.com)
 using an Arduino Wiznet Ethernet shield.

 Circuit:
 * Ethernet shield attached to pins 10, 11, 12, 13

 created 18 Dec 2009
 by David A. Mellis
 modified 9 Apr 2012
 by Tom Igoe, based on work by Adrian McEwen

 */

#include <SPI.h>
#include <Ethernet.h>

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

// if you don't want to use DNS (and reduce your sketch size)
// use the numeric IP instead of the name for the server:
IPAddress server(192, 168, 1, 177);  // numeric IP for Google (no DNS)
//char server[] = "www.google.com";    // name address for Google (using DNS)

// Set the static IP address to use if the DHCP fails to assign
IPAddress ip(192, 168, 0, 178);

// Initialize the Ethernet client library
// with the IP address and port of the server
// that you want to connect to (port 80 is default for HTTP):
EthernetClient client;

// Variables to measure the speed
unsigned long beginMicros, endMicros;
unsigned long byteCount = 0;
bool printWebData = true;  // set to false for better speed measurement

void setup() {
  // You can use Ethernet.init(pin) to configure the CS pin
  Ethernet.init(10);  // Most Arduino shields
  //Ethernet.init(5);   // MKR ETH shield
  //Ethernet.init(0);   // Teensy 2.0
  //Ethernet.init(20);  // Teensy++ 2.0
  //Ethernet.init(15);  // ESP8266 with Adafruit Featherwing Ethernet
  //Ethernet.init(33);  // ESP32 with Adafruit Featherwing Ethernet

  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }

  // give the Ethernet shield a second to initialize:
  delay(1000);
  Serial.print("connecting to ");
  Serial.print(server);
  Serial.println("...");

  // if you get a connection, report back via serial:
  if (client.connect(server, 80)) {
    Serial.print("connected to ");
    Serial.println(client.remoteIP());
    // Make a HTTP request:
    client.println("GET /search?q=arduino HTTP/1.1");
    client.println("Host: www.google.com");
    client.println("Connection: close");
    client.println();
  } else {
    // if you didn't get a connection to the server:
    Serial.println("connection failed");
  }
  beginMicros = micros();
}

void loop() {
  // if there are incoming bytes available
  // from the server, read them and print them:
  int len = client.available();
  if (len > 0) {
    byte buffer[80];
    if (len > 80) len = 80;
    client.read(buffer, len);
    if (printWebData) {
      Serial.write(buffer, len); // show in the serial monitor (slows some boards)
    }
    byteCount = byteCount + len;
  }

  // if the server's disconnected, stop the client:
  if (!client.connected()) {
    endMicros = micros();
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();
    Serial.print("Received ");
    Serial.print(byteCount);
    Serial.print(" bytes in ");
    float seconds = (float)(endMicros - beginMicros) / 1000000.0;
    Serial.print(seconds, 4);
    float rate = (float)byteCount / seconds / 1000.0;
    Serial.print(", rate = ");
    Serial.print(rate);
    Serial.print(" kbytes/second");
    Serial.println();

    // do nothing forevermore:
    while (true) {
      delay(1);
    }
  }
}

Since the W5100 Ethernet controller chip used on your shield does auto-MDIX, you should be fine using a regular Ethernet cable, rather than a crossover cable.

You need to give each board a different IP address.

You're missing the call to Ethernet.begin() in your Client sketch.

Thank you for fast answer and taking time for trying helping me.

I’ve check again but my IP are good i think…?

I have add Ethernet.begin(mac,ip); to my client setup function.

Here my serial result :

connecting to 192.168.1.177...
connection failed

disconnecting.
Received 0 bytes in 0.0000, rate = 0.00 kbytes/second

Hi all,

I have try new more simple code but that still didn’t work… check my new code please…

My Ip and Mac are different, the remote ip and port are good in my client and i still use a straight RJ45 cable…

I don’t understand… Please i need some help…

Client

#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>

EthernetUDP Udp;
byte mac[] = {0x90, 0xA2, 0xDA, 0x0D, 0x5C, 0x18};
IPAddress ip(192,168,1,15);
unsigned int localport = 8888;

IPAddress remoteIP(192,168,1,16);
unsigned int remotePort = 8888;

void setup(){
 Serial.begin(9600);
 Serial.println("****************");
 Serial.println("Serial OK");
 Ethernet.begin(mac,ip);
 Ethernet.init(10);
 Serial.print("IP : ");
 Serial.println(Ethernet.localIP());
 Udp.begin(localport);
}

void loop(){
 Udp.beginPacket(remoteIP, remotePort);
 Udp.println("Message UDP");
 Serial.println("Message UDP");
 Udp.endPacket();
 delay(5000);
}

Server

#include <SPI.h>        
#include <Ethernet.h>
#include <EthernetUdp.h>

// Server MAC adress
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};

// Server IP adress
IPAddress ip(192, 168, 1, 16);

// local port to listen on
unsigned int localPort = 8888;

EthernetUDP Udp;

//buffer to hold incoming packet,
char packetBuffer[UDP_TX_PACKET_MAX_SIZE];

void setup() {
  // start the Ethernet and UDP:
  Ethernet.begin(mac,ip);
  Ethernet.init(10);
  Udp.begin(localPort);

}

void loop() {

  int packetSize = Udp.parsePacket();
  if(packetSize)
  {
    Serial.print("Received packet of size ");
    Serial.println(packetSize);
    Serial.print("From ");
    IPAddress remote = Udp.remoteIP();
    for (int i =0; i < 4; i++)
    {
      Serial.print(remote[i], DEC);
      if (i < 3)
      {
        Serial.print(".");
      }
    }
    Serial.print(", port ");
    Serial.println(Udp.remotePort());

    // read the packet into packetBufffer
    Udp.read(packetBuffer,UDP_TX_PACKET_MAX_SIZE);
    Serial.println("Contents:");
    Serial.println(packetBuffer);
}
}

Best regards, Ludo

I would use a cross cable. and init() after begin() is useless