Create Ethernet XML Output


I apologise if this has been posted before. I have searched but couldn't find exactly what I was looking for.

I would like to interface Arduino with OpenHAB. There seems to be numerous methods of doing so, and using Souliss (the easiest method) doesnt work for me because I'm using other parts of OpenHAB which conflict with it.

I want to very simply read the arduino Uno or Mega (with Ethernet) pin values and import those values to OpenHAB. I think the next simplest method of achieving this is to use an XML output and GET requests from OpenHAB.

My programming skills are extremely basic. I've seen various XML examples of extracting data from websites, but not necessarily presenting arduino pin values.

Could someone possibly please point me in the direction or provide a sample of code that:
a) Compatible with Arduino Uno/Mega with Ethernet Shield.
b) Reads digital and analog pins and outputs a very basic XML web page of pin values (analog and digital).

I have already studied to achieve the writing of data via GET requests. If the example could embed some capability allowing the writing of values that would be a bonus.

Once again I apologise if I have missed something elsewhere on the web, but nothing seems simple enough / compatible that I have seen.

Many, many thanks in advance.

Could someone possibly please point me in the direction or provide a sample of code that:
a) Compatible with Arduino Uno/Mega with Ethernet Shield.
b) Reads digital and analog pins and outputs a very basic XML web page of pin values (analog and digital).

Below is web server code that supplies the value of the analog pins in a web page, but no xml.

// zoomkat's meta refresh data frame test page 5/25/13
// use in your brouser for main page
// static data page
// meta refresh data page
// for use with W5100 based ethernet shields
// set the refresh rate to 0 for fastest update
// use STOP for single data updates

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

const int analogInPin0 = A0;
const int analogInPin1 = A1;
const int analogInPin2 = A2;
const int analogInPin3 = A3;
const int analogInPin4 = A4;
const int analogInPin5 = A5;

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 102 }; // arduino ip in lan
byte gateway[] = { 192, 168, 1, 1 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(84); //server port
unsigned long int x=0; //set refresh counter to 0
String readString; 


void setup(){
    // disable SD SPI if memory card in the uSD slot

  Ethernet.begin(mac, ip, gateway, gateway, subnet);
  Serial.println("meta refresh data frame test 5/25/13"); // so I can keep track of what is loaded

void loop(){
  EthernetClient client = server.available();
  if (client) {
    while (client.connected()) {
      if (client.available()) {
        char c =;
         if (readString.length() < 100) {
          readString += c; 
        //check if HTTP request has ended
        if (c == '\n') {

          //check get atring received

          //output HTML data header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");

          //generate data page
          if(readString.indexOf("data") >0) {  //checks for "data" page
            x=x+1; //page upload counter
            //meta-refresh page every 1 seconds if "datastart" page
            if(readString.indexOf("datastart") >0) client.print("<meta http-equiv='refresh' content='1'>"); 
            //meta-refresh 0 for fast data
            if(readString.indexOf("datafast") >0) client.print("<meta http-equiv='refresh' content='0'>"); 
            client.print("<title>Zoomkat's meta-refresh test</title></head><BODY>
            client.print("page refresh number: ");
            client.print(x); //current refresh count

              //output the value of each analog input pin
            client.print("analog input0 is: ");
analog input1 is: ");
analog input2 is: ");
analog input3 is: ");
analog input4 is: ");
analog input5 is: ");
          //generate main page with iframe
            client.print("<HTML><HEAD><TITLE>Zoomkat's frame refresh test</TITLE></HEAD>");
            client.print("Zoomkat's Arduino frame meta refresh test 5/25/13");

Arduino analog input data frame:
            client.print("&nbsp;&nbsp;<a href='' target='DataBox' title=''yy''>META-REFRESH</a>");
            client.print("&nbsp;&nbsp;&nbsp;&nbsp;<a href='' target='DataBox' title=''xx''>SINGLE-STOP</a>");
            client.print("&nbsp;&nbsp;&nbsp;&nbsp;<a href='' target='DataBox' title=''zz''>FAST-DATA</a>
            client.print("<iframe src='' width='350' height='250' name='DataBox'>");
          //stopping client
          //clearing string for next read

Simply do

client.println(F("<?xml version = \"1.0\" encoding=\"UTF-8\"?>"));

Hey guys

Thank you very much :slight_smile:

I found that using the client print takes up a lot of processing power. Try this tutorial and see if it helps you out, it really helped me with my home automation project i was working on.