void switch2transmit() {

  disableRx = true;
  // ------------------ GO TO TRANSMIT STATE -------------------------
  digitalWrite(txEnablePin, HIGH);
  delayMicroseconds( 400 );
  // ------------------ GO TO TRANSMIT STATE -------------------------
}

void switch2receive() {
  // ------------------ GO TO RECEIVE STATE -------------------------
  // From Transmission Mode to Receiver Mode follow the procedure:
  // Drive down pin 5 (RX/TX), after 40us drive down pin 6 (ENABLE) 20us long.
  //After 200 us the device is ready for reception.
  digitalWrite(txEnablePin, LOW); 
  delayMicroseconds( 40 ); 
  digitalWrite(enablePin, LOW); 
  delayMicroseconds( 20 ); 
  digitalWrite(enablePin, HIGH);  
  delayMicroseconds( 200 );
  // ------------------ GO TO RECEIVE STATE -------------------------
  disableRx = false;
}

void sendPulse(int high, int low) {

  digitalWrite(txPin, HIGH); 
  delayMicroseconds( high ); 
  digitalWrite(txPin, LOW); 
  delayMicroseconds( low );  
}

// Nexa : http://elektronikforumet.com/wiki/index.php/RF_Protokoll_-_Nexa_sj%C3%A4lvl%C3%A4rande
// "1" = 295 µs hög och 170 µs låg
// "0" = 295 µs hög och 920 µs låg
// 
// Etta skickas som 10 och Nolla som 01
//
// Dessa siffror från web-sidan stämmer inte med den Nexa-kontroll som jag har.
// Jag har rättat dessa med siffror från verkligheten. Finns i define's nedan.

// <NT01995080>
// <NT01995090>

// Timing for NEXA Remote controls
#define HIGH_PULSE     240
#define LOW_PULSE_0    300
#define LOW_PULSE_1   1300
#define SYNC_PULSE    2700
#define STOP_PULSE   10000

void send1() {

  sendPulse( HIGH_PULSE, LOW_PULSE_1);    // 1
  sendPulse( HIGH_PULSE, LOW_PULSE_0 );   // 0
}

void send0() {

  sendPulse( HIGH_PULSE, LOW_PULSE_0 );   // 0
  sendPulse( HIGH_PULSE, LOW_PULSE_1);    // 1  
}

void sendSync() {
  sendPulse( HIGH_PULSE, SYNC_PULSE );  
}

void sendStop() {
  sendPulse( HIGH_PULSE, STOP_PULSE );
}

void sendNexaCode(unsigned long int txCode) {

  unsigned long int code=0;
  unsigned long int orig_code=txCode;  
  int i;
  int loop;

  if( 1 == 1 ) {

    // Turn off interrupts from the timer
    TIMSK1 = 0;
    
    switch2transmit();

    for( loop=6; loop>0; loop--) {
      
      code = orig_code;
      
      sendSync();

      for(i=0; i < 32; i++) {

        if( code & 0x80000000 ) {
          send1();
        }
        else {
          send0();
        }
        code = (code << 1);
      }
      sendStop();      
    }

    switch2receive();
    
    // Enable interrupts again
    TIMSK1 |= (1 << OCIE1A);
  }
}