diff --git a/hardware/arduino/avr/cores/arduino/CDC.cpp b/hardware/arduino/avr/cores/arduino/CDC.cpp
index d694a2d2ca8..280696ff809 100644
--- a/hardware/arduino/avr/cores/arduino/CDC.cpp
+++ b/hardware/arduino/avr/cores/arduino/CDC.cpp
@@ -49,8 +49,8 @@ const CDCDescriptor _cdcInterface =
 
 	//	CDC data interface
 	D_INTERFACE(CDC_DATA_INTERFACE,2,CDC_DATA_INTERFACE_CLASS,0,0),
-	D_ENDPOINT(USB_ENDPOINT_OUT(CDC_ENDPOINT_OUT),USB_ENDPOINT_TYPE_BULK,0x40,0),
-	D_ENDPOINT(USB_ENDPOINT_IN (CDC_ENDPOINT_IN ),USB_ENDPOINT_TYPE_BULK,0x40,0)
+	D_ENDPOINT(USB_ENDPOINT_OUT(CDC_ENDPOINT_OUT), USB_ENDPOINT_TYPE_BULK, USB_EP_SIZE, 0),
+	D_ENDPOINT(USB_ENDPOINT_IN(CDC_ENDPOINT_IN), USB_ENDPOINT_TYPE_BULK, USB_EP_SIZE, 0)
 };
 
 int CDC_GetInterface(u8* interfaceNum)
@@ -78,11 +78,13 @@ bool CDC_Setup(USBSetup& setup)
 		if (CDC_SET_LINE_CODING == r)
 		{
 			USB_RecvControl((void*)&_usbLineInfo,7);
+			CDC_LineEncodingEvent();
 		}
 
 		if (CDC_SET_CONTROL_LINE_STATE == r)
 		{
 			_usbLineInfo.lineState = setup.wValueL;
+			CDC_LineStateEvent();
 		}
 
 		if (CDC_SET_LINE_CODING == r || CDC_SET_CONTROL_LINE_STATE == r)
@@ -92,11 +94,25 @@ bool CDC_Setup(USBSetup& setup)
 			// with a relatively long period so it can finish housekeeping tasks
 			// like servicing endpoints before the sketch ends
 
+#ifndef MAGIC_KEY
+#define MAGIC_KEY 0x7777
+#endif
+#ifndef MAGIC_KEY_POS
+#define MAGIC_KEY_POS (uint16_t *)0x0800
+#endif
+// NO_MAGIC_KEY_BACKUP can be used if you want to store the key in the safer RAMEND directly, so no backup is needed
+
 			// We check DTR state to determine if host port is open (bit 0 of lineState).
 			if (1200 == _usbLineInfo.dwDTERate && (_usbLineInfo.lineState & 0x01) == 0)
 			{
-				*(uint16_t *)(RAMEND-1) = *(uint16_t *)0x0800;
-				*(uint16_t *)0x0800 = 0x7777;
+#if !defined(NO_MAGIC_KEY_BACKUP)
+				*(uint16_t *)(RAMEND-1) = *MAGIC_KEY_POS;
+				*MAGIC_KEY_POS = MAGIC_KEY;
+#else
+				// for future boards save the key in the inproblematic RAMEND
+				// which is reserved for the main() return value (which will never return)
+				*MAGIC_KEY_POS = MAGIC_KEY;
+#endif
 				wdt_enable(WDTO_120MS);
 			}
 			else
@@ -108,7 +124,11 @@ bool CDC_Setup(USBSetup& setup)
 
 				wdt_disable();
 				wdt_reset();
-				*(uint16_t *)0x0800 = *(uint16_t *)(RAMEND-1);
+#if !defined(NO_MAGIC_KEY_BACKUP)
+				*MAGIC_KEY_POS = *(uint16_t *)(RAMEND-1);
+#else
+				*MAGIC_KEY_POS = 0x0000;
+#endif
 			}
 		}
 		return true;
@@ -116,6 +136,15 @@ bool CDC_Setup(USBSetup& setup)
 	return false;
 }
 
+void WEAK CDC_LineEncodingEvent(void)
+{
+	// has to be implemented by the user
+}
+
+void WEAK CDC_LineStateEvent(void)
+{
+	// has to be implemented by the user
+}
 
 void Serial_::begin(unsigned long /* baud_count */)
 {
@@ -190,6 +219,36 @@ size_t Serial_::write(const uint8_t *buffer, size_t size)
 	return 0;
 }
 
+uint32_t Serial_::baud(void)
+{
+	return _usbLineInfo.dwDTERate;
+}
+
+uint8_t Serial_::stopbits(void)
+{
+	return _usbLineInfo.bCharFormat;
+}
+
+uint8_t Serial_::paritytype(void)
+{
+	return _usbLineInfo.bParityType;
+}
+
+uint8_t Serial_::numbits(void)
+{
+	return _usbLineInfo.bDataBits;
+}
+
+bool Serial_::dtr(void)
+{
+	return (_usbLineInfo.lineState & CDC_CONTROL_LINE_OUT_DTR) ? true : false;
+}
+
+bool Serial_::rts(void)
+{
+	return (_usbLineInfo.lineState & CDC_CONTROL_LINE_OUT_RTS) ? true : false;
+}
+
 // This operator is a convenient way for a sketch to check whether the
 // port has actually been configured and opened by the host (as opposed
 // to just being connected to the host).  It can be used, for example, in 
diff --git a/hardware/arduino/avr/cores/arduino/USBAPI.h b/hardware/arduino/avr/cores/arduino/USBAPI.h
index 4abd9616f33..2b9b983905b 100644
--- a/hardware/arduino/avr/cores/arduino/USBAPI.h
+++ b/hardware/arduino/avr/cores/arduino/USBAPI.h
@@ -26,12 +26,18 @@
 #include <avr/interrupt.h>
 #include <util/delay.h>
 
-typedef unsigned char u8;
+typedef unsigned char u8; //TODO remove
 typedef unsigned short u16;
 typedef unsigned long u32;
 
 #include "Arduino.h"
 
+// this definitions is usefull if you want to reduce the EP_SIZE to 16
+// at the moment only 64 and 16 as EP_SIZE for all EPs are supported except the control endpoint
+#ifndef USB_EP_SIZE
+#define USB_EP_SIZE 64
+#endif
+
 #if defined(USBCON)
 
 #include "USBDesc.h"
@@ -41,13 +47,13 @@ typedef unsigned long u32;
 //================================================================================
 //	USB
 
-#define EP_TYPE_CONTROL				0x00
-#define EP_TYPE_BULK_IN				0x81
-#define EP_TYPE_BULK_OUT			0x80
-#define EP_TYPE_INTERRUPT_IN		0xC1
-#define EP_TYPE_INTERRUPT_OUT		0xC0
-#define EP_TYPE_ISOCHRONOUS_IN		0x41
-#define EP_TYPE_ISOCHRONOUS_OUT		0x40
+#define EP_TYPE_CONTROL				(0x00)
+#define EP_TYPE_BULK_IN				((1<<EPTYPE1) | (1<<EPDIR))
+#define EP_TYPE_BULK_OUT			(1<<EPTYPE1)
+#define EP_TYPE_INTERRUPT_IN		((1<<EPTYPE1) | (1<<EPTYPE0) | (1<<EPDIR))
+#define EP_TYPE_INTERRUPT_OUT		((1<<EPTYPE1) | (1<<EPTYPE0))
+#define EP_TYPE_ISOCHRONOUS_IN		((1<<EPTYPE0) | (1<<EPDIR))
+#define EP_TYPE_ISOCHRONOUS_OUT		(1<<EPTYPE0)
 
 class USBDevice_
 {
@@ -96,6 +102,12 @@ class Serial_ : public Stream
 	virtual size_t write(uint8_t);
 	virtual size_t write(const uint8_t*, size_t);
 	using Print::write; // pull in write(str) and write(buf, size) from Print
+	uint32_t baud(void);
+	uint8_t stopbits(void);
+	uint8_t paritytype(void);
+	uint8_t numbits(void);
+	bool dtr(void);
+	bool rts(void);
 	operator bool();
 
 	volatile uint8_t _rx_buffer_head;
@@ -136,6 +148,8 @@ bool	MSC_Data(uint8_t rx,uint8_t tx);
 int		CDC_GetInterface(uint8_t* interfaceNum);
 int		CDC_GetDescriptor(int i);
 bool	CDC_Setup(USBSetup& setup);
+void	CDC_LineEncodingEvent(void);
+void	CDC_LineStateEvent(void);
 
 //================================================================================
 //================================================================================
diff --git a/hardware/arduino/avr/cores/arduino/USBCore.cpp b/hardware/arduino/avr/cores/arduino/USBCore.cpp
index 8237ccb2c47..c3190a71184 100644
--- a/hardware/arduino/avr/cores/arduino/USBCore.cpp
+++ b/hardware/arduino/avr/cores/arduino/USBCore.cpp
@@ -110,7 +110,7 @@ static inline void ClearOUT(void)
 	UEINTX = ~(1<<RXOUTI);
 }
 
-void Recv(volatile u8* data, u8 count)
+static inline void Recv(volatile u8* data, u8 count)
 {
 	while (count--)
 		*data++ = UEDATX;
@@ -253,7 +253,7 @@ u8 USB_SendSpace(u8 ep)
 	LockEP lock(ep);
 	if (!ReadWriteAllowed())
 		return 0;
-	return 64 - FifoByteCount();
+	return USB_EP_SIZE - FifoByteCount();
 }
 
 //	Blocking Send of data to an endpoint
@@ -326,6 +326,7 @@ u8 _initEndpoints[] =
 
 #define EP_SINGLE_64 0x32	// EP0
 #define EP_DOUBLE_64 0x36	// Other endpoints
+#define EP_SINGLE_16 0x12
 
 static
 void InitEP(u8 index, u8 type, u8 size)
@@ -344,7 +345,13 @@ void InitEndpoints()
 		UENUM = i;
 		UECONX = (1<<EPEN);
 		UECFG0X = _initEndpoints[i];
-		UECFG1X = EP_DOUBLE_64;
+#if USB_EP_SIZE == 16
+		UECFG1X = EP_SINGLE_16;
+#elif USB_EP_SIZE == 64
+ 		UECFG1X = EP_DOUBLE_64;
+#else
+#error Unsupported value for USB_EP_SIZE
+#endif
 	}
 	UERST = 0x7E;	// And reset them
 	UERST = 0;
@@ -620,40 +627,56 @@ void USB_Flush(u8 ep)
 
 static inline void USB_ClockDisable()
 {
-	USBCON = (USBCON & ~(1<<OTGPADE)) | (1<<FRZCLK); // freeze clock and disable VBUS Pad
-	PLLCSR &= ~(1<<PLLE);  // stop PLL
+#if defined(OTGPADE)
+	USBCON = (USBCON & ~(1 << OTGPADE)) | (1 << FRZCLK); // freeze clock and disable VBUS Pad
+#else // u2 Series
+	USBCON = (1 << FRZCLK); // freeze clock
+#endif
+	PLLCSR &= ~(1 << PLLE);  // stop PLL
 }
 
 static inline void USB_ClockEnable()
 {
-	UHWCON |= (1<<UVREGE);			// power internal reg
-	USBCON = (1<<USBE) | (1<<FRZCLK);	// clock frozen, usb enabled
+#if defined(UHWCON)
+	UHWCON |= (1 << UVREGE);			// power internal reg
+#endif
+	USBCON = (1 << USBE) | (1 << FRZCLK);	// clock frozen, usb enabled
 
-// ATmega32U4
+	// ATmega32U4
 #if defined(PINDIV)
 #if F_CPU == 16000000UL
-	PLLCSR |= (1<<PINDIV);                   // Need 16 MHz xtal
+	PLLCSR |= (1 << PINDIV);                   // Need 16 MHz xtal
 #elif F_CPU == 8000000UL
-	PLLCSR &= ~(1<<PINDIV);                  // Need  8 MHz xtal
+	PLLCSR &= ~(1 << PINDIV);                  // Need  8 MHz xtal
 #else
 #error "Clock rate of F_CPU not supported"
 #endif
 
-// AT90USB646, AT90USB647, AT90USB1286, AT90USB1287
+#elif defined(__AVR_AT90USB82__) || defined(__AVR_AT90USB162__) || defined(__AVR_ATmega32U2__) || defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega8U2__)
+	// for the u2 Series the datasheet is confusing. On page 40 its called PINDIV and on page 290 its called PLLP0
+#if F_CPU == 16000000UL
+	// Need 16 MHz xtal
+	PLLCSR |= (1 << PLLP0);
+#elif F_CPU == 8000000UL
+	// Need 8 MHz xtal
+	PLLCSR &= ~(1 << PLLP0);
+#endif
+
+	// AT90USB646, AT90USB647, AT90USB1286, AT90USB1287
 #elif defined(PLLP2)
 #if F_CPU == 16000000UL
 #if defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__)
 	// For Atmel AT90USB128x only. Do not use with Atmel AT90USB64x.
-	PLLCSR = (PLLCSR & ~(1<<PLLP1)) | ((1<<PLLP2) | (1<<PLLP0)); // Need 16 MHz xtal
+	PLLCSR = (PLLCSR & ~(1 << PLLP1)) | ((1 << PLLP2) | (1 << PLLP0)); // Need 16 MHz xtal
 #elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__)
 	// For AT90USB64x only. Do not use with AT90USB128x.
-	PLLCSR = (PLLCSR & ~(1<<PLLP0)) | ((1<<PLLP2) | (1<<PLLP1)); // Need 16 MHz xtal
+	PLLCSR = (PLLCSR & ~(1 << PLLP0)) | ((1 << PLLP2) | (1 << PLLP1)); // Need 16 MHz xtal
 #else
 #error "USB Chip not supported, please defined method of USB PLL initialization"
 #endif
 #elif F_CPU == 8000000UL
 	// for Atmel AT90USB128x and AT90USB64x
-	PLLCSR = (PLLCSR & ~(1<<PLLP2)) | ((1<<PLLP1) | (1<<PLLP0)); // Need 8 MHz xtal
+	PLLCSR = (PLLCSR & ~(1 << PLLP2)) | ((1 << PLLP1) | (1 << PLLP0)); // Need 8 MHz xtal
 #else
 #error "Clock rate of F_CPU not supported"
 #endif
@@ -661,8 +684,8 @@ static inline void USB_ClockEnable()
 #error "USB Chip not supported, please defined method of USB PLL initialization"
 #endif
 
-	PLLCSR |= (1<<PLLE);
-	while (!(PLLCSR & (1<<PLOCK)))		// wait for lock pll
+	PLLCSR |= (1 << PLLE);
+	while (!(PLLCSR & (1 << PLOCK)))		// wait for lock pll
 	{
 	}
 
@@ -670,13 +693,21 @@ static inline void USB_ClockEnable()
 	// strange behaviors when the board is reset using the serial
 	// port touch at 1200 bps. This delay fixes this behavior.
 	delay(1);
-	USBCON = (USBCON & ~(1<<FRZCLK)) | (1<<OTGPADE);	// start USB clock, enable VBUS Pad
+#if defined(OTGPADE)
+	USBCON = (USBCON & ~(1 << FRZCLK)) | (1 << OTGPADE);	// start USB clock, enable VBUS Pad
+#else
+	USBCON &= ~(1 << FRZCLK);	// start USB clock
+#endif
 
 #if defined(RSTCPU)
-	UDCON &= ~((1<<RSTCPU) | (1<<LSM) | (1<<RMWKUP) | (1<<DETACH));	// enable attach resistor, set full speed mode
+#if defined(LSM)
+	UDCON &= ~((1 << RSTCPU) | (1 << LSM) | (1 << RMWKUP) | (1 << DETACH));	// enable attach resistor, set full speed mode
+#else // u2 Series
+	UDCON &= ~((1 << RSTCPU) | (1 << RMWKUP) | (1 << DETACH));	// enable attach resistor, set full speed mode
+#endif
 #else
 	// AT90USB64x and AT90USB128x don't have RSTCPU
-	UDCON &= ~((1<<LSM) | (1<<RMWKUP) | (1<<DETACH));	// enable attach resistor, set full speed mode
+	UDCON &= ~((1 << LSM) | (1 << RMWKUP) | (1 << DETACH));	// enable attach resistor, set full speed mode
 #endif
 }
 
diff --git a/hardware/arduino/avr/cores/arduino/USBCore.h b/hardware/arduino/avr/cores/arduino/USBCore.h
index 66f8c05f135..9d8e4c3f939 100644
--- a/hardware/arduino/avr/cores/arduino/USBCore.h
+++ b/hardware/arduino/avr/cores/arduino/USBCore.h
@@ -58,6 +58,9 @@
 #define CDC_GET_LINE_CODING			0x21
 #define CDC_SET_CONTROL_LINE_STATE	0x22
 
+#define CDC_CONTROL_LINE_OUT_DTR   (1 << 0)
+#define CDC_CONTROL_LINE_OUT_RTS   (1 << 1)
+
 #define MSC_RESET					0xFF
 #define MSC_GET_MAX_LUN				0xFE
 
@@ -88,6 +91,20 @@
 #define USB_DEVICE_CLASS_STORAGE               0x08
 #define USB_DEVICE_CLASS_VENDOR_SPECIFIC       0xFF
 
+// added new definitions for correct USB descriptors
+// there are even more, these are the ones we need
+#define USB_DEVICE_CLASS_IAD                   0xEF
+#define USB_DEVICE_SUB_CLASS_IAD               0x02
+#define USB_DEVICE_PROTOCOL_IAD                0x01
+
+#define USB_DEVICE_CDC_CLASS                   0x02
+#define USB_DEVICE_CDC_SUB_CLASS               0x00
+#define USB_DEVICE_CDC_PROTOCOL                0x00 // NoSpecific Protocol
+
+#define USB_DEVICE_NO_CLASS                    0x00
+#define USB_DEVICE_NO_SUB_CLASS                0x00
+#define USB_DEVICE_NO_PROTOCOL                 0x00
+
 #define USB_CONFIG_POWERED_MASK                0x40
 #define USB_CONFIG_BUS_POWERED                 0x80
 #define USB_CONFIG_SELF_POWERED                0xC0
@@ -276,4 +293,4 @@ typedef struct
 #define D_CDCCS4(_subtype,_d0)		{ 4, 0x24, _subtype, _d0 }
 
 
-#endif
\ No newline at end of file
+#endif
diff --git a/hardware/arduino/avr/libraries/HID/HID.cpp b/hardware/arduino/avr/libraries/HID/HID.cpp
index 0d2133ec799..7f8335a9f8b 100644
--- a/hardware/arduino/avr/libraries/HID/HID.cpp
+++ b/hardware/arduino/avr/libraries/HID/HID.cpp
@@ -59,7 +59,7 @@ int HID_GetInterface(u8* interfaceNum)
 	{
 		D_INTERFACE(HID_INTERFACE,1,3,0,0),
 		D_HIDREPORT(sizeof_hidReportDescriptor),
-		D_ENDPOINT(USB_ENDPOINT_IN (HID_ENDPOINT_INT),USB_ENDPOINT_TYPE_INTERRUPT,0x40,0x01)
+		D_ENDPOINT(USB_ENDPOINT_IN (HID_ENDPOINT_INT),USB_ENDPOINT_TYPE_INTERRUPT, USB_EP_SIZE ,0x01)
 	};
 	return USB_SendControl(0,&_hidInterface,sizeof(_hidInterface));
 }
diff --git a/hardware/arduino/avr/libraries/HID/HID.h b/hardware/arduino/avr/libraries/HID/HID.h
index 89832a9afef..72a5a945eba 100644
--- a/hardware/arduino/avr/libraries/HID/HID.h
+++ b/hardware/arduino/avr/libraries/HID/HID.h
@@ -88,10 +88,10 @@ typedef struct
 #define HID_TX HID_ENDPOINT_INT
 
 #define D_HIDREPORT(_descriptorLength) \
-  { 9, 0x21, 0x1, 0x1, 0, 1, 0x22, _descriptorLength, 0 }
+  { 9, 0x21, 0x1, 0x1, 0, 1, 0x22, _descriptorLength, _descriptorLength >> 8 }
 
 #define WEAK __attribute__ ((weak))
 
 #endif
 
-#endif
\ No newline at end of file
+#endif