Merge pull request #21 from myelin/add-serial-dtr

Add Adafruit_USBD_CDC::dtr()

Author: hathach

Adafruit_USBD_CDC.cpp

@@ -99,6 +99,11 @@ uint8_t Adafruit_USBD_CDC::numbits(void)
   return coding.data_bits;
 }
 
+int Adafruit_USBD_CDC::dtr(void)
+{
+  return tud_cdc_connected();
+}
+
 Adafruit_USBD_CDC::operator bool()
 {
   bool ret = tud_cdc_connected();

Adafruit_USBD_CDC.h

@@ -46,6 +46,7 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface
 	uint8_t  stopbits(void);
 	uint8_t  paritytype(void);
 	uint8_t  numbits(void);
+	int      dtr(void);
 
 	virtual int    available(void);
 	virtual int    peek(void);