Weather LCD display via XML

To read the XML from Yahoo Weather API you can use the TextFinder library.

Before you read the weather data you need to get the ID (woeid) from your city.

Example: Zurich/Switzerland
http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20geo.places%20where%20text%3D"Schweiz%20Zürich"&format=xml

You will find the ID in the field

Code to read the Yahoo Weather API

//
// Read Yahoo Weather API XML
// 03.09.2012
// http://arduino-praxis.ch


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

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xAD };
byte ip[] = { 10, 0, 1, 101 };
byte gateway[] = { 10, 0, 1, 1 };
byte subnet[] = { 255, 255, 255, 0 };

// Server Yahoo
IPAddress server(87,248,122,181);

EthernetClient client;
TextFinder  finder( client );  

char place[50];
char hum[30];


void setup()
{
  // Start Ehternet
  Ethernet.begin(mac, ip);
  // Start Serial Port
  Serial.begin(9600);
  Serial.println("Setup...");
}


void loop()
{
  if (client.connect(server, 80))
  {
    // Call Wetter-API
    // w: ID from your City
    // http://weather.yahooapis.com/forecastrss?w=12893459&u=c
    ///
    Serial.println("Connect to Yahoo Weather...");
    client.println("GET /forecastrss?w=12893459&u=c HTTP/1.0");
    client.println("HOST:weather.yahooapis.com\n\n");
    client.println();
    Serial.println("Connected...");
  } 
  else
  {
    Serial.println(" connection failed");
  } 
 

  if (client.connected())
  {
    
    // Humidity
   if ( (finder.getString("<yweather:atmosphere humidity=\"", "\"",hum,4)!=0) )
   {
     Serial.print("Humidity:  ");
     Serial.println(hum);
   } 
   else
   {
     Serial.print("No Humidity Data");
   }
    
    
    // Place/City
    if ( (finder.getString("<title>Conditions for ", " ",place,50)!=0) )
    {
      Serial.print("City:  ");
      Serial.println(place);
    }
    
    
    // Temperature
    if(finder.find("temp=") )
    {
     int temperature = finder.getValue();
     Serial.print("Temp C:  ");
     Serial.println(temperature);
   }
   else
   {
     Serial.print("No Temperature Data");
   }
   
         
  // END XML
  }
  else
  {
    Serial.println("Disconnected"); 
  }
 
  client.stop();
  client.flush();
  delay(60000); 
}