Twitter from Aruduino + Ethernet Shield

1.Get a token to post a message using OAuth.

• open url: http://arduino-tweet.appspot.com/oauth/twitter/login

• Click  at  "Authorize app"

• Save you Token: xxxYouTokenxxx

2.Add some Libraries to your Arduino IDE. 

• Download the Arduino Tweet Library http://arduino-tweet.appspot.com/Library-Twitter-1.3.zip
• Unzip and copy Twitter folder to you install arduino C:\Software\Arduino\arduino-1.0.3\libraries
• Re-start the Arduino IDE.

3. Run a sample sketch SimplePost to tweet!

• Open Sketch > Twitter > SimplePort

• Config you IP and Twitter Token

byte ip[] = { 192, 168, 200, 200 };
Twitter twitter(" xxxYouTokenxxx");

• Compile and Upload
• Open Serial to Check Eror
• Open you twitter to check tweet from Arduino

5.Test Tweet Temperature & Humidity from DHT11 Sensor

Source TwitterDHT11.ino

#include <SPI.h> // needed in Arduino 0019 or later
#include <Ethernet.h>
#include <Twitter.h>

// Ethernet Shield Settings
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

// If you don't specify the IP address, DHCP is used(only in Arduino 1.0 or later).
byte ip[] = { 192, 168, 200, 200};

// Your Token to Tweet (get it from http://arduino-tweet.appspot.com/)
Twitter twitter("xxxTwitterTokenxxx");

// DHT11 Defint Libraries
/*-----( Import needed libraries )-----*/
#include <dht11.h>
/*-----( Declare objects )-----*/
dht11 DHT11;
/*-----( Declare Constants,Digital Pin Numbers )-----*/
#define DHT11PIN 2

void setup()
{
  delay(1000);
  Ethernet.begin(mac, ip);
  // or you can use DHCP for autoomatic IP address configuration.
  // Ethernet.begin(mac);
  Serial.begin(9600);
}

void loop()
{
  String message;

  int chk = DHT11.read(DHT11PIN);
  switch (chk)
  {
    case 0: Serial.print("OK! "); break;
    case -1: Serial.print("Checksum error! "); break;
    case -2: Serial.print("Time out error! "); break;
    default: Serial.print("Unknown error! "); break;
  }
  message = "Temperature (C): " + String(DHT11.temperature);
  message +=   " Humidity (%): " + String(DHT11.humidity) ;
  Serial.println(message);
  tweet(message);
  delay(60000);
}

void tweet(String message)
{
  char msg[100] = "";
  message.toCharArray(msg, 100);
  Serial.println("connecting ...");
  if (twitter.post(msg)) {
    int status = twitter.wait();
    if (status == 200) {
      Serial.println("OK.");
    } else {
      Serial.print("failed : code ");
      Serial.println(status);
    }
  } else {
    Serial.println("connection failed.");
  }
  delay(1000); }