add Ethernet library for W5100

libraries/Ethernet/examples/ChatServer/ChatServer.ino

@@ -0,0 +1,80 @@
+/*
+ Chat  Server
+
+ A simple server that distributes any incoming messages to all
+ connected clients.  To use telnet to  your device's IP address and type.
+ You can see the client's input in the serial monitor as well.
+ 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
+
+ */
+
+#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.
+// gateway and subnet are optional:
+byte mac[] = {
+  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
+};
+IPAddress ip(192, 168, 1, 177);
+IPAddress gateway(192, 168, 1, 1);
+IPAddress subnet(255, 255, 0, 0);
+
+
+// telnet defaults to port 23
+EthernetServer server(23);
+boolean alreadyConnected = false; // whether or not the client was connected previously
+
+void setup() {
+  // initialize the ethernet device
+  Ethernet.begin(mac, ip, gateway, subnet);
+  // start listening for clients
+  server.begin();
+  // Open serial communications and wait for port to open:
+  Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for Leonardo only
+  }
+
+
+  Serial.print("Chat server address:");
+  Serial.println(Ethernet.localIP());
+}
+
+void loop() {
+  // wait for a new client:
+  EthernetClient client = server.available();
+
+  // when the client sends the first byte, say hello:
+  if (client) {
+    if (!alreadyConnected) {
+      // clead out the input buffer:
+      client.flush();
+      Serial.println("We have a new client");
+      client.println("Hello, client!");
+      alreadyConnected = true;
+    }
+
+    if (client.available() > 0) {
+      // read the bytes incoming from the client:
+      char thisChar = client.read();
+      // echo the bytes back to the client:
+      server.write(thisChar);
+      // echo the bytes to the server as well:
+      Serial.write(thisChar);
+    }
+  }
+}
+
+
+