hi there,
i'm here to share my project, it's just a simple keyfob programming/receiver to be connected to our mysensors net. I use this to control my surveillance sistem (activation/deactivation).
i wrote this sketch for mysensors 1.5, so maybe it need to be translated for latest version.
my coding it's so rude, so i hope someone can also improve it.
later i will post schematic and the used component list.
cheers

#include <MySensor.h>
#include <SPI.h>
#include <RCSwitch.h> 
#include <EEPROMEx.h>

#define STATIC_ID 4
#define CHILD_ID 1

RCSwitch RFKey = RCSwitch();

const byte progSwitch = 4;                  // Prgram button
const byte ledGreen = 6;                  // green led
const byte ledRed = 7;                  // red led

unsigned long lastAvailable = 0;
unsigned long previousMillis = 0; 

int timeout = 3000;               // set unlock timeout here

MySensor gw;
MyMessage msg(CHILD_ID,V_TRIPPED);
int oldValue=-1;
unsigned long code1, code2, code3;

void setup() { 
  gw.begin(NULL, STATIC_ID, false);

  pinMode(progSwitch, INPUT_PULLUP);      // Prog button
  pinMode(ledGreen, OUTPUT);              // unlock/learning
  pinMode(ledRed, OUTPUT);                // invalid code/stop learnig

  RFKey.enableTransmit(3);     // Transmitter is connected to Arduino Pin #3  
  RFKey.enableReceive(0);  // Receiver on inerrupt 0 => that is pin #2

  gw.sendSketchInfo("Ricevitore 433 MHZ", "1.0");
  gw.present(CHILD_ID, S_DOOR); 
 
  code1 = EEPROM.readLong( 50 ); 
  code2 = EEPROM.readLong( 100 ); 
  code3 = EEPROM.readLong( 150 ); 
  
}

void loop() {

  if ( !digitalRead(progSwitch) ) {                    // check button
    unsigned long lastMillis = 0;
    previousMillis = millis();
    while ( !digitalRead(progSwitch) ) {
      lastMillis = millis();
    }
    if ( (lastMillis - previousMillis) > 10000 ){                 // press button 10sec
      updateCode();                                               // change remote codes 
    }
    else if ( (lastMillis - previousMillis) > 200 ){              // debounce
      progRemote();                                               // send radio code to remotes learn
    }
  }
  ////////////////////////////////////////////////////////
  if ( RFKey.available() ) {       // multicode control
    blinkLed(ledRed, 1, 50); 
    unsigned long receivedCode = RFKey.getReceivedValue();
    RFKey.resetAvailable();
    

   Serial.println (receivedCode);

    if ( receivedCode == code1 ){       // check first code  

      unsigned long checkTime = millis();
      receivedCode = 0;
      boolean flag = false;

      while ( millis() < (checkTime + timeout) ) {
        if ( RFKey.available() ) {
          blinkLed(ledRed, 1, 50);
          receivedCode = RFKey.getReceivedValue();
          RFKey.resetAvailable();
          if ( receivedCode == code2 ){                //check second code 
            Serial.println ("*** UNLOCKED ***");
            digitalWrite( ledGreen, HIGH);
            digitalWrite( ledRed, LOW);            
            gw.send(msg.set(0==HIGH ? 1 : 0));             // send unlock code
            flag = true;
            break;
          } 
        }
      } 
      if (flag == false){
        gw.send(msg.set(1==HIGH ? 1 : 0)); 
        blinkLed(ledGreen, 1, 100);
        Serial.println ("*** LOCKED ***");
        digitalWrite( ledGreen, LOW);
        digitalWrite( ledRed, HIGH);         
        RFKey.resetAvailable();
        unsigned long checkTime = millis();
        receivedCode = 0;
      } 
    }
    else if ( receivedCode == code3 ) {                // CODICE AUX
        gw.send(msg.set(2)); 
        blinkLed(ledGreen, 1, 100);
        Serial.println ("*** AUX ***");
        delay(3000);
        RFKey.resetAvailable();
        receivedCode = 0;    
    }
    
    else{
      RFKey.resetAvailable();
      delay (1000);
      Serial.println("*** invalid code ***");
      Serial.print("received code: ");
      Serial.println(receivedCode);
      receivedCode = 0;
    }
  }
}



void progRemote(){                                    // keyfob programming

  unsigned long code1 = EEPROM.readLong( 50 ); 
  unsigned long code2 = EEPROM.readLong( 100 ); 
  unsigned long code3 = EEPROM.readLong( 150 );   

  Serial.println("--- CODE 1 ---");
  sendCode(code1);
  Serial.println("terminated");
  blinkLed(ledRed, 1, 1000);

  Serial.println("--- CODE 2 ---");
  sendCode(code2);
  Serial.println("terminated");
  blinkLed(ledRed, 1, 1000);
  
  Serial.println("--- CODE 3 ---");
  sendCode(code3);
  Serial.println("terminated");
  blinkLed(ledRed, 1, 1000);  
}


void sendCode ( unsigned long sendCode) {
  Serial.print("Sending code (20sec): ");
  Serial.println( sendCode );
  previousMillis = millis();
  unsigned long lastLedBlink = millis();
  boolean ledStatus = false;

  while ( millis() < ( previousMillis + 20000 ) ) {
    RFKey.send( sendCode, 24 );
    blinkLed(ledGreen, 1, 50);
  }

}

////////////////////////////////////////////////////////////////////////////

void updateCode() {                                          // chandge radio code
  Serial.println("change radio code");

  //unsigned long randomCode1 = random (1000000,9999999);
  unsigned long randomCode1 = random (1000,4094);          // 12 bit
 // randomCode1 = 3618;
  Serial.print ("Codice random1 : ");
  Serial.println(randomCode1);

  //unsigned long randomCode2 = random (1000000,9999999);
  unsigned long randomCode2 = random (1000,4094);          // 12 bit  
 // randomCode2 = 2769;
  Serial.print ("Codice random2 : ");
  Serial.println(randomCode2);

  //unsigned long randomCode3 = random (1000000,9999999);
  unsigned long randomCode3 = random (1000,4094);          // 12 bit
 // randomCode3 = 1720;
  Serial.print ("Codice random3 : ");
  Serial.println(randomCode3);


  EEPROM.writeLong( 50 , randomCode1 ); 
  EEPROM.writeLong( 100 , randomCode2 );
  EEPROM.writeLong( 150 , randomCode3 );   
  blinkLed(ledGreen, 1, 3000); 
}

////////////////////////////////////////////////////////////////////////////

void checkCode() {                                            // check received code
  unsigned long receivedCode = RFKey.getReceivedValue();
  unsigned long code1 = EEPROM.readLong( 50 ); 
  unsigned long code2 = EEPROM.readLong( 100 ); 

  if ( receivedCode == code1 ){       // check first code
    blinkLed(ledGreen, 1, 100);
    Serial.println ("first code unlocked");
    RFKey.resetAvailable();
    unsigned long checkTime = millis();
    receivedCode = 0;
    while ( millis() < (checkTime + 3000) ) {
      //    Serial.println ("while");
      if ( RFKey.available() ) {
        receivedCode = RFKey.getReceivedValue();
        if ( receivedCode == code2 ){                //check second code
          // Serial.println ("second code unlocked");
          RFKey.resetAvailable();
          Serial.println("*** valid code received ***");
          //          ALstatus = !ALstatus;
          //          return true;
        }
      }
    }
  }
 
  else{
    RFKey.resetAvailable();
    delay (1000);
    Serial.println("*** invalid code ***");
    Serial.print("received code: ");
    Serial.println(receivedCode);
    //  return false;
  }
}

////////////////////////////////////////////////////////////////////////////

void blinkLed(byte ledPin, byte times, int Delay){
  for ( int i = 0; i < times; i++){
    digitalWrite (ledPin, HIGH);
    delay (Delay);
    digitalWrite (ledPin, LOW);
    delay (Delay);
  }
}

////////////////////////////////////////////////////////////////////////////



/*
Instruction
 press PROG button to send code for keyfob programming
 hold PROG about 10 sec. to reset and generate new code for keyfob programming
 */