The Twitter Button is Back in Business! 
(Expect updated code soon)
Note: Twitter changed its authentication system to reject basic http auth...
This <del>might</del> does work: [[http://www.arduino.cc/playground/Code/TwitterLibrary|http://www.arduino.cc/playground/Code/TwitterLibrary]]
=====  Summary  =====
The "Twitter Button" project's goal is to use a big red HAL9000 button to indicate via twitter that a keyholder is present at [[NSL]] 
The project has since been expanded to include an RFID reader to identify keyholders in addition to the button.

===== Status =====
**Active Use!**
The button is up and mounted next to the door!
Current twitter button status can be viewed on the [[When Are You There?]] page :)

=====  Objectives  =====
Completed:
  *  Light up button while "NSL is open"
  *  Tweet status
  *  Status change by button-press
  *  Read and Identify RFID card
  *  Status change by RFID read
  *  Specific status change based on RFID card used
  *  Twitter session [[no|longer]] expires after 10 min.
  *  Twitter wont let you "retweet" past posts... (<del>need to make</del> each post [[is|now]] unique)

In Progress:
  *  Configure for keyholder RFID cards... So far I have a handful of cards set up, let me know if I've missed you...
  *  Package into Box
  *  Sleep

Current Issues:
  *  Twitter has a limit on posts per hour... not nice for testing
  *  Fit everything into the box, need to play more tetris. (I think that everything fits now)
  *  Make holes in box for power/ethernet/usb/program mode button

Future Plans:
  *  Authenticate RFID with a Python app on server.

=====  Code - Basic Concept  =====
''
<code>
  - include <Ethernet.h>

byte mac[[]] = { 0xde, 0xad, 0xbe, 0xef, 0xfe, 0xed };
byte ip[[]] = { 10, 0, 5, 247 };\t\t\t    // this is the ip within my lan
byte gateway[[]] = { 10, 0, 0, 1 };\t\t\t// neccessary to get access to the internet via your router
byte subnet[[]] = { 255, 0, 0, 0 };
byte server[[]] = { 128, 121, 146, 100 };\t\t   // Twitter's ip

Client client(server, 80);

void setup()
{
<code>
  Ethernet.begin(mac, ip, gateway, subnet);
  Serial.begin(9600);
  delay(1000);
  Serial.println(`connecting...`);
  if (client.connect()) {
    Serial.println(`connected`);
    client.println(`POST http://twitter.com/statuses/update.json HTTP/1.1`);
    client.println(`Host: twitter.com`);
    client.println(`Authorization: Basic XXXXXXXXXXXXX`);// the string of ###s after `Basic` is the base64_encoded Text of username:password of your twitter account</code>
    
\t\t\t\t\t\t\t\t\t\t\t\t// you can do the encoding at this site: http://www.functions-online.com/en/base64_encode.html
<code>
    client.println(`Content-type: application/x-www-form-urlencoded`);
    client.println(`Content-length: 28`);\t\t\t\t\t // this is the length of the text `Yahoo, im twittering!`
    client.println(`Connection: Close`);
    client.println();
    client.print(`status=Yahoo, im twittering!`);
  } else {
    Serial.println(`connection failed`);
  }</code>
}

void loop()
{
<code>
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }
  if (!client.connected()) {
    Serial.println();
    Serial.println(`disconnecting.`);
    client.stop();
    for(;;)</code>
\t;
<code>
  }</code>
} 
</code>
''

=====  Contact  =====
Any inquiries/suggestions should be told/sent/given/yelled to [[Davo]] in person, via the nsl list, or via IRC... :)