RFIDreaderforArduino.pde

// RFID reader for Arduino 
// Wiring version by BARRAGAN <http://people.interaction-ivrea.it/h.barragan> 
// Modified for Arudino by djmatic

#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = { 192, 168, 1, 200 };
byte gateway[] = { 192, 168, 1, 1 };
byte subnet[] = { 255, 255, 255, 0 };
byte server[] = { 128, 121, 146, 100 };

Client client(server, 80);

#define TWITTERURL "/statuses/update.xml"  // URL zum Update Script
#define TWITTERUSERNAMEPW "ZmZhZXJi-----G9semRvc2U="  // Base64 enkodet USERNAME:PASSWORT


int  val = 0; 
char code[10]; 
int bytesread = 0; 

void setup() { 
  Ethernet.begin(mac, ip, gateway, subnet);  // Ethernet initalisiere
  Serial.begin(2400); // RFID reader SOUT pin connected to Serial RX pin at 2400bps
  delay(1000);  // Kurz warten, um serielle Verbindung zu starten

  pinMode(2,OUTPUT);   // Set digital pin 2 as OUTPUT to connect it to the RFID /ENABLE pin 
  digitalWrite(2, LOW);                  // Activate the RFID reader
}


 void loop() { 
  fetchTwitterUpdate();

  if(Serial.available() > 0) {          // if data available from reader 
    if((val = Serial.read()) == 10) {   // check for header 
      bytesread = 0; 
      while(bytesread<10) {              // read 10 digit code 
        if( Serial.available() > 0) { 
          val = Serial.read(); 
          if((val == 10)||(val == 13)) { // if header or stop bytes before the 10 digit reading 
            break;                       // stop reading 
          } 
          code[bytesread] = val;         // add the digit           
          bytesread++;                   // ready to read next digit  
        }
      } 
      if(bytesread == 10) {              // if 10 digit read is complete 
        Serial.print("TAG code is: ");   // possibly a good TAG 
        sendTwitterUpdate(code);  // Nachricht versenden
        Serial.println(code);            // print the TAG code 
      } 
      bytesread = 0; 
      delay(500);                       // wait for a second 
    } 
  } 
} 





void sendTwitterUpdate(char* tweet)        // Nachricht an Twitter übermitteln
{
   Serial.println("connecting...");
 
  if (client.connect()) {
    Serial.println("connected");
 
    client.print("POST ");
    client.print(TWITTERURL);
    client.println(" HTTP/1.1");
    client.println("Host: twitter.com");
    client.print("Authorization: Basic ");
    client.println(TWITTERUSERNAMEPW);
    client.print("Content-Length: ");
    client.println(9+strlen(tweet));
    client.println("");
    client.println("status=");
    client.println(tweet);
    Serial.println("twitter message send");
  } else {
    Serial.println("connection failed");
  } 

}


void fetchTwitterUpdate()     // Rückmeldung von Twitter auslesen
{
    if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }
 
  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();
  }
}

// extra stuff
// digitalWrite(2, HIGH);             // deactivate RFID reader