你能试试这个代码吗?
#if defined(ARDUINO) && ARDUINO > 18
#include <SPI.h>
#endif
#include <Ethernet.h>
#include <EthernetDHCP.h>
// MAC Address
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
const char* ip_to_str(const uint8_t*);
// Initialize the Ethernet server library
Server server(8080);
void setup()
{
  Serial.begin(9600);
  Serial.println("Attempting to obtain a DHCP lease...");
  // Initiate a DHCP session. The argument is the MAC (hardware) address that
  // you want your Ethernet shield to use. This call will block until a DHCP
  // lease has been obtained. The request will be periodically resent until
  // a lease is granted, but if there is no DHCP server on the network or if
  // the server fails to respond, this call will block forever.
  // Thus, you can alternatively use polling mode to check whether a DHCP
  // lease has been obtained, so that you can react if the server does not
  // respond (see the PollingDHCP example).
  EthernetDHCP.begin(mac);
  // Since we're here, it means that we now have a DHCP lease, so we print
  // out some information.
  const byte* ipAddr = EthernetDHCP.ipAddress();
  const byte* gatewayAddr = EthernetDHCP.gatewayIpAddress();
  const byte* dnsAddr = EthernetDHCP.dnsIpAddress();
  Serial.println("A DHCP lease has been obtained.");
  Serial.print("My IP address is ");
  Serial.println(ip_to_str(ipAddr));
  Serial.print("Gateway IP address is ");
  Serial.println(ip_to_str(gatewayAddr));
  Serial.print("DNS IP address is ");
  Serial.println(ip_to_str(dnsAddr));
  // Start the server
   server.begin();
}
void loop()
{
  // You should periodically call this method in your loop(): It will allow
  // the DHCP library to maintain your DHCP lease, which means that it will
  // periodically renew the lease and rebind if the lease cannot be renewed.
  // Thus, unless you call this somewhere in your loop, your DHCP lease might
  // expire, which you probably do not want :-)
  EthernetDHCP.maintain();
  // listen for incoming clients
  Client client = server.available();
  if (client) {
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        // 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();
          // Some misc. HTML 
          client.println("<title>Arduino Control Panel</title>");
          client.println("<center><h1>Control Panel</h1></center>");
          client.println("<p></p>");
          // output the value of each analog input pin
          for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
            client.print("Analog input ");
            client.print(analogChannel);
            client.print(" is ");
            client.print(analogRead(analogChannel));
            client.println("<br />");
          }
          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();
  }
}
// Just a utility function to nicely format an IP address.
const char* ip_to_str(const uint8_t* ipAddr)
{
  static char buf[16];
  sprintf(buf, "%d.%d.%d.%d\0", ipAddr[0], ipAddr[1], ipAddr[2], ipAddr[3]);
  return buf;
}