Arduino

#include "SD.h"
#include "Ethernet.h"
#include "SPI.h"
#include "WebServer.h"

File MioFile;

template<class T>
inline Print &operator <<(Print &obj, T arg)
{
  obj.print(arg);
  return obj;
}

static byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
static byte ip[] = { 10, 0, 1, 100 };
#define PREFIX ""
WebServer webserver(PREFIX, 80);

void outputJson(WebServer &server, WebServer::ConnectionType type, char *url_tail, bool tail_complete) {

  server.httpSuccess("application/json");

  if (type == WebServer::HEAD)
    return;

  server << "{";
  server << "\"temperature\": " << checkTemperature(0) << ", ";
  server << " }";
}

void initSD() {
  if (SD.begin(4) == true) {
    if (SD.exists("conf/conf.txt")) {
      MioFile = SD.open("conf/conf.txt", FILE_READ);
      if (MioFile == true) {
        while (MioFile.available())
        {
          Serial.write(MioFile.read());
        }

        MioFile.close();
      }
    }
    else {
      SD.mkdir("conf");
      MioFile = SD.open("conf/conf.txt", FILE_WRITE);

      if (MioFile != false)
        MioFile.println("empty.");
    }
  }
  else {
    Serial.println("Errore nella lettura della SD Card.");
  }
}

float checkTemperature(int tempPin) {
  float temp;
  temp = analogRead(tempPin);
  temp = temp * 0.48828125;
  delay(200);
  return temp;
}

void setup() {
  Serial.begin(9600);
  //updateIpAddress();
  initSD();

  Ethernet.begin(mac, ip);
  webserver.begin();
  webserver.setDefaultCommand(&outputJson);
}

void loop() {
  //float temp = checkTemperature(0);
  webserver.processConnection();
  //checkIpAddress();
}