Arduino Ethernet  W5100網絡擴展模塊，可以使Arduino成為簡單的Web服務器或者通過網絡控制讀寫Arduino的數字和模擬接口等網絡應用。可直接使用IDE中的Ethernet庫文件便可實現一個簡單Web服務器。
    同時該版本的支持mini SD卡（TF卡）讀寫
該擴展板采用了可堆疊的設計，可直接插到Arduino上，同時我們的其他擴展板也可以插上去。
代碼：
/*
 * Web Server
 *
 * A simple web server that shows the value of the analog input pins.
 */
 
 
#include
 
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] =  { 192, 168, 0, 15 };
Server server(80);
void setup()
{
  Ethernet.begin(mac, ip);
  server.begin();
}
void loop()
{
  Client client = server.available();
  if (client) {
    // an http request ends with a blank line
    boolean current_line_is_blank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        // if we\'ve gotten to the end of the line (received a newline
        // character) and the line is blank, the http request has ended,
        // so we can send a reply
        if (c == \'\\n\' && current_line_is_blank) {
          // send a standard http response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println();
         
          // output the value of each analog input pin
          client.print("welcome to tinyos");
          client.println("
");
          client.print("//*************************************");
          client.println("
");
          client.print(www.tinyos.net.cn);
          client.println("
");
          client.print("//*************************************");
          client.println("
");
          for (int i = 0; i < 6; i++) {
            client.print("analog input ");
            client.print(i);
            client.print(" is ");
            client.print(analogRead(i));
            client.println("
");
          }
          break;
        }
        if (c == \'\\n\') {
          // we\'re starting a new line
          current_line_is_blank = true;
        } else if (c != \'\\r\') {
          // we\'ve gotten a character on the current line
          current_line_is_blank = false;
        }
      }
    }
    client.stop();
  }
}