Adding Serial.end().

cores/arduino/HardwareSerial.cpp

@@ -165,6 +165,13 @@ void HardwareSerial::begin(long baud)
   sbi(*_ucsrb, _rxcie);
 }
 
+void HardwareSerial::end()
+{
+  cbi(*_ucsrb, _rxen);
+  cbi(*_ucsrb, _txen);
+  cbi(*_ucsrb, _rxcie);  
+}
+
 uint8_t HardwareSerial::available(void)
 {
   return (RX_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % RX_BUFFER_SIZE;

cores/arduino/HardwareSerial.h

@@ -47,6 +47,7 @@ class HardwareSerial : public Print
       volatile uint8_t *udr,
       uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udre, uint8_t u2x);
     void begin(long);
+    void end();
     uint8_t available(void);
     int read(void);
     void flush(void);