Arduino Ethernet Shieldを使う

電子工作 Arduino

電源ON時にリセットをかける方法（コンデンサのハンダ付け）
http://todotani.cocolog-nifty.com/blog/2010/06/arduino-etherne.html

サンプルコード

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

byte mac[] = { 
  0x90, 0xA2, 0xDA, 0x00, 0x21, 0x3B };
IPAddress ip(192,168,1, 177);
EthernetServer server(80);

void setup() {
  Ethernet.begin(mac, ip);
  server.begin();
}

void loop() {
  EthernetClient client = server.available();
  if (client) {
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        if (c == '\n' && currentLineIsBlank) {
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connnection: close");
          client.println();
          client.println("<!DOCTYPE HTML>");
          client.println("<html>");
          client.println("<meta http-equiv=\"refresh\" content=\"5\">");
          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("<br />");       
          }
          client.println("</html>");
          break;
        }
        if (c == '\n') {
          currentLineIsBlank = true;
        } 
        else if (c != '\r') {
          currentLineIsBlank = false;
        }
      }
    }
    delay(1);
    client.stop();
  }
}