diff --git a/hardware/arduino/sam/cores/sam/USB/USBAPI.h b/hardware/arduino/sam/cores/sam/USB/USBAPI.h
index 8a248ae11..f06380bf0 100644
--- a/hardware/arduino/sam/cores/sam/USB/USBAPI.h
+++ b/hardware/arduino/sam/cores/sam/USB/USBAPI.h
@@ -15,8 +15,8 @@ public:
 	USB_();
 	bool configured();
 
-	void attach();
-	void detach();	// Serial port goes down too...
+	bool attach();
+	bool detach();	// Serial port goes down too...
 	void poll();
 };
 extern USB_ USB;
diff --git a/hardware/arduino/sam/cores/sam/USB/USBCore.cpp.disabled b/hardware/arduino/sam/cores/sam/USB/USBCore.cpp.disabled
index f4587e97f..4b352afa4 100644
--- a/hardware/arduino/sam/cores/sam/USB/USBCore.cpp.disabled
+++ b/hardware/arduino/sam/cores/sam/USB/USBCore.cpp.disabled
@@ -94,8 +94,9 @@ const DeviceDescriptor USB_DeviceDescriptorA =
 //==================================================================
 //==================================================================
 
-volatile uint8_t _usbConfiguration = 0;
-uint8_t _cdcComposite = 0;
+volatile uint32_t _usbConfiguration = 0;
+volatile uint32_t _usbInitialized = 0;
+uint32_t _cdcComposite = 0;
 
 
 //==================================================================
@@ -129,7 +130,7 @@ int USBD_Recv(uint8_t ep, void* d, int len)
   }
 
 	n = FifoByteCount(ep);
-  
+
 	len = min(n,len);
 	n = len;
 	dst = (uint8_t*)d;
@@ -151,16 +152,16 @@ static bool USBD_SendControl(uint8_t d)
     {
 			return false;
     }
-      
+
 		Send8( d ) ;
-    
+
 		if ( !((_cmark + 1) & 0x3F) )
     {
 			ClearIN();	// Fifo is full, release this packet
     }
 	}
 	_cmark++;
-  
+
 	return true ;
 }
 
@@ -173,7 +174,7 @@ int USBD_SendControl(uint8_t flags, const void* d, int len)
 	while ( len-- )
 	{
 		uint8_t c = *data++ ;
-    
+
 		if ( !SendControl( c ) )
     {
 			return -1;
@@ -293,7 +294,7 @@ static bool USBD_SendDescriptor(Setup& setup)
   {
 		return false ;
   }
-  
+
 	if ( desc_length == 0 )
   {
 		desc_length = *desc_addr;
@@ -308,7 +309,7 @@ static bool USBD_SendDescriptor(Setup& setup)
 void USB_ISR()
 {
   SetEP(0) ;
-  
+
 	if ( !ReceivedSetupInt() )
   {
 		return;
@@ -367,7 +368,7 @@ void USB_ISR()
 			{
 				InitEndpoints();
 				_usbConfiguration = setup.wValueL;
-			} 
+			}
       else
       {
 				ok = false;
@@ -458,17 +459,38 @@ USB_ USB;
 
 USB_::USB_()
 {
+  if ( USBD_Init() == 0UL )
+  {
+    _usbInitialized=1UL ;
+  }
 }
 
-void USB_::attach(void)
+bool USB_::attach(void)
 {
-  USBD_Attach() ;
+  if ( _usbInitialized != 0UL )
+  {
+    USBD_Attach() ;
+
+    return true ;
+  }
+  else
+  {
+    return false ;
+  }
 }
 
-void USB_::detach(void)
+bool USB_::detach(void)
 {
-    UDPHS->UDPHS_CTRL |= UDPHS_CTRL_DETACH; // detach
-    UDPHS->UDPHS_CTRL &= ~UDPHS_CTRL_PULLD_DIS; // Enable Pull Down
+  if ( _usbInitialized != 0UL )
+  {
+    USBD_Detach() ;
+
+    return true ;
+  }
+  else
+  {
+    return false ;
+  }
 }
 
 //	Check for interrupts
diff --git a/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk b/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk
index fc312592a..d698e7787 100644
--- a/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk
+++ b/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk
@@ -148,8 +148,6 @@ create_output:
 #	@echo *$(A_SRC)
 #	@echo -------------------------
 
-#	-@mkdir $(subst /,$(SEP),$(OUTPUT_BIN)) 1>NUL 2>&1
-	-mkdir $(subst /,$(SEP),$(OUTPUT_BIN))
 	-@mkdir $(OUTPUT_PATH) 1>NUL 2>&1
 
 $(addprefix $(OUTPUT_PATH)/,$(C_OBJ)): $(OUTPUT_PATH)/%.o: %.c
diff --git a/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3x_ek.mk b/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3x_ek.mk
index a444f7527..7eabc0c37 100644
--- a/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3x_ek.mk
+++ b/hardware/arduino/sam/cores/sam/build_gcc/libarduino_sam3x_ek.mk
@@ -148,8 +148,6 @@ create_output:
 #	@echo *$(A_SRC)
 #	@echo -------------------------
 
-#	-@mkdir $(subst /,$(SEP),$(OUTPUT_BIN)) 1>NUL 2>&1
-	-mkdir $(subst /,$(SEP),$(OUTPUT_BIN))
 	-@mkdir $(OUTPUT_PATH) 1>NUL 2>&1
 
 $(addprefix $(OUTPUT_PATH)/,$(C_OBJ)): $(OUTPUT_PATH)/%.o: %.c
diff --git a/hardware/arduino/sam/system/libsam/include/USB_device.h b/hardware/arduino/sam/system/libsam/include/USB_device.h
index 6a6950db3..49baf0c04 100644
--- a/hardware/arduino/sam/system/libsam/include/USB_device.h
+++ b/hardware/arduino/sam/system/libsam/include/USB_device.h
@@ -8,7 +8,7 @@
 
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU Lesser General Public License for more details.
 
   You should have received a copy of the GNU Lesser General Public
@@ -64,6 +64,8 @@ extern void USBD_InitEndpoints(void) ;
 
 extern void USBD_InitControl(int end) ;
 
+extern uint32_t USBD_Init(void) ;
+
 extern void USBD_Attach(void) ;
 extern void USBD_Detach(void) ;
 
diff --git a/hardware/arduino/sam/system/libsam/include/uotghs.h b/hardware/arduino/sam/system/libsam/include/uotghs.h
index 01de19e5f..df5f89958 100644
--- a/hardware/arduino/sam/system/libsam/include/uotghs.h
+++ b/hardware/arduino/sam/system/libsam/include/uotghs.h
@@ -8,7 +8,7 @@
 
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU Lesser General Public License for more details.
 
   You should have received a copy of the GNU Lesser General Public
@@ -19,4 +19,29 @@
 #ifndef UOTGHS_H_INCLUDED
 #define UOTGHS_H_INCLUDED
 
+#define EP_SINGLE_64 (0x32UL) // EP0
+#define EP_DOUBLE_64 (0x36UL) // Other endpoints
+
+
+// Control Endpoint
+#define EP_TYPE_CONTROL           (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_CTRL | UOTGHS_DEVEPTCFG_EPBK_1_BANK)
+
+// CDC Endpoints
+#ifdef CDC_ENABLED
+#define EP_TYPE_BULK_IN           (UOTGHS_DEVEPTCFG_EPSIZE_512_BYTE | UOTGHS_DEVEPTCFG_EPDIR_IN | UOTGHS_DEVEPTCFG_EPTYPE_BLK | UOTGHS_DEVEPTCFG_EPBK_2_BANK)
+#define EP_TYPE_BULK_OUT          (UOTGHS_DEVEPTCFG_EPSIZE_512_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_BLK | UOTGHS_DEVEPTCFG_EPBK_2_BANK)
+#define EP_TYPE_INTERRUPT_IN      (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPDIR_IN | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPBK_2_BANK)
+#endif
+
+// HID Endpoints
+#ifdef HID_ENABLED
+#define EP_TYPE_INTERRUPT_IN_HID	(UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPDIR_IN | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPBK_2_BANK)
+#endif
+
+// Various definitions
+#define EP_TYPE_INTERRUPT_OUT		  (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPBK_1_BANK)
+#define EP_TYPE_ISOCHRONOUS_IN		(UOTGHS_DEVEPTCFG_EPSIZE_1024_BYTE | UOTGHS_DEVEPTCFG_EPDIR_IN | UOTGHS_DEVEPTCFG_EPTYPE_ISO | UOTGHS_DEVEPTCFG_EPBK_3_BANK)
+#define EP_TYPE_ISOCHRONOUS_OUT		(UOTGHS_DEVEPTCFG_EPSIZE_1024_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_ISO | UOTGHS_DEVEPTCFG_EPBK_3_BANK)
+
+
 #endif /* UOTGHS_H_INCLUDED */
diff --git a/hardware/arduino/sam/system/libsam/source/uotghs.c b/hardware/arduino/sam/system/libsam/source/uotghs.c
index 5052f0207..ab2b5927a 100644
--- a/hardware/arduino/sam/system/libsam/source/uotghs.c
+++ b/hardware/arduino/sam/system/libsam/source/uotghs.c
@@ -8,7 +8,7 @@
 
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU Lesser General Public License for more details.
 
   You should have received a copy of the GNU Lesser General Public
@@ -20,5 +20,157 @@
 
 #if SAM3XA_SERIES
 
+void USBD_InitEndpoints(void)
+{
+}
+
+uint32_t USBD_Init(void)
+{
+  uint32_t ul ;
+
+  // Enables the USB Clock
+	pmc_enable_periph_clk(ID_UOTGHS);
+	pmc_enable_upll_clock();
+	pmc_switch_udpck_to_upllck(0); // div=0+1
+	pmc_enable_udpck();
+
+  // Configure interrupts
+	NVIC_SetPriority((IRQn_Type) ID_UOTGHS, 0UL);
+	NVIC_EnableIRQ((IRQn_Type) ID_UOTGHS);
+
+	// Always authorize asynchrone USB interrupts to exit from sleep mode
+	//   for SAM3 USB wake up device except BACKUP mode
+	pmc_set_fast_startup_input(PMC_FSMR_USBAL);
+
+  // Enable USB macro
+  UOTGHS->UOTGHS_CTRL |= UOTGHS_CTRL_USBE;
+
+  // Automatic mode speed for device
+  UOTGHS->UOTGHS_DEVCTRL &= ~UOTGHS_DEVCTRL_SPDCONF_Msk;  // Normal mode
+
+  UOTGHS->UOTGHS_DEVCTRL &= ~( UOTGHS_DEVCTRL_LS | UOTGHS_DEVCTRL_TSTJ | UOTGHS_DEVCTRL_TSTK |
+                                UOTGHS_DEVCTRL_TSTPCKT | UOTGHS_DEVCTRL_OPMODE2 ); // Normal mode
+
+  UOTGHS->UOTGHS_DEVCTRL = 0;
+  UOTGHS->UOTGHS_HSTCTRL = 0;
+
+  // Enable OTG pad
+  UOTGHS->UOTGHS_CTRL |= UOTGHS_CTRL_OTGPADE;
+
+  // Enable clock OTG pad
+  UOTGHS->UOTGHS_CTRL &= ~UOTGHS_CTRL_FRZCLK;
+
+  // Usb disable
+  UOTGHS->UOTGHS_CTRL &= ~UOTGHS_CTRL_USBE;
+  UOTGHS->UOTGHS_CTRL &= ~UOTGHS_CTRL_OTGPADE;
+  UOTGHS->UOTGHS_CTRL |= UOTGHS_CTRL_FRZCLK;
+
+  // Usb enable
+  UOTGHS->UOTGHS_CTRL |= UOTGHS_CTRL_USBE;
+  UOTGHS->UOTGHS_CTRL |= UOTGHS_CTRL_OTGPADE;
+  UOTGHS->UOTGHS_CTRL &= ~UOTGHS_CTRL_FRZCLK;
+
+  // Usb select_device
+  UOTGHS->UOTGHS_CTRL &= ~UOTGHS_CTRL_UIDE;
+  UOTGHS->UOTGHS_CTRL |= UOTGHS_CTRL_UIMOD_Device;
+
+  // Device is in the Attached state
+//  deviceState = USBD_STATE_SUSPENDED;
+//  previousDeviceState = USBD_STATE_POWERED;
+
+  // Enable USB macro and clear all other bits
+  UOTGHS->UOTGHS_DEVCTRL |= UOTGHS_CTRL_USBE;
+  UOTGHS->UOTGHS_DEVCTRL = UOTGHS_CTRL_USBE;
+
+  // Configure the pull-up on D+ and disconnect it
+  USBD_Detach();
+
+  // Clear General IT
+  UOTGHS->UOTGHS_SCR = (UOTGHS_SCR_IDTIC|UOTGHS_SCR_VBUSTIC|UOTGHS_SCR_SRPIC|UOTGHS_SCR_VBERRIC|UOTGHS_SCR_BCERRIC|UOTGHS_SCR_ROLEEXIC|UOTGHS_SCR_HNPERRIC|UOTGHS_SCR_STOIC|UOTGHS_SCR_VBUSRQC);
+
+  // Clear OTG Device IT
+  UOTGHS->UOTGHS_DEVICR = (UOTGHS_DEVICR_SUSPC|UOTGHS_DEVICR_MSOFC|UOTGHS_DEVICR_SOFC|UOTGHS_DEVICR_EORSTC|UOTGHS_DEVICR_WAKEUPC|UOTGHS_DEVICR_EORSMC|UOTGHS_DEVICR_UPRSMC);
+
+  // Clear OTG Host IT
+  UOTGHS->UOTGHS_HSTICR = (UOTGHS_HSTICR_DCONNIC|UOTGHS_HSTICR_DDISCIC|UOTGHS_HSTICR_RSTIC|UOTGHS_HSTICR_RSMEDIC|UOTGHS_HSTICR_RXRSMIC|UOTGHS_HSTICR_HSOFIC|UOTGHS_HSTICR_HWUPIC);
+
+  // Reset all Endpoints Fifos
+  UOTGHS->UOTGHS_DEVEPT |= (UOTGHS_DEVEPT_EPRST0|UOTGHS_DEVEPT_EPRST1|UOTGHS_DEVEPT_EPRST2|UOTGHS_DEVEPT_EPRST3|UOTGHS_DEVEPT_EPRST4|
+                             UOTGHS_DEVEPT_EPRST5|UOTGHS_DEVEPT_EPRST6|UOTGHS_DEVEPT_EPRST7|UOTGHS_DEVEPT_EPRST8);
+  UOTGHS->UOTGHS_DEVEPT &= ~(UOTGHS_DEVEPT_EPRST0|UOTGHS_DEVEPT_EPRST1|UOTGHS_DEVEPT_EPRST2|UOTGHS_DEVEPT_EPRST3|UOTGHS_DEVEPT_EPRST4|
+                              UOTGHS_DEVEPT_EPRST5|UOTGHS_DEVEPT_EPRST6|UOTGHS_DEVEPT_EPRST7|UOTGHS_DEVEPT_EPRST8);
+
+  // Disable all endpoints
+  UOTGHS->UOTGHS_DEVEPT &= ~(UOTGHS_DEVEPT_EPEN0|UOTGHS_DEVEPT_EPEN1|UOTGHS_DEVEPT_EPEN2|UOTGHS_DEVEPT_EPEN3|UOTGHS_DEVEPT_EPEN4|
+                              UOTGHS_DEVEPT_EPEN5|UOTGHS_DEVEPT_EPEN6|UOTGHS_DEVEPT_EPEN7|UOTGHS_DEVEPT_EPEN8);
+
+  // Device is in the Attached state
+//  deviceState = USBD_STATE_SUSPENDED;
+//  previousDeviceState = USBD_STATE_POWERED;
+
+  // Automatic mode speed for device
+  UOTGHS->UOTGHS_DEVCTRL &= ~UOTGHS_DEVCTRL_SPDCONF_Msk;
+  // Force Full Speed mode for device
+  //UOTGHS->UOTGHS_DEVCTRL = UOTGHS_DEVCTRL_SPDCONF_FORCED_FS;
+  // Force High Speed mode for device
+  //UOTGHS->UOTGHS_DEVCTRL = UOTGHS_DEVCTRL_SPDCONF_HIGH_SPEED;
+
+  UOTGHS->UOTGHS_DEVCTRL &= ~(UOTGHS_DEVCTRL_LS|UOTGHS_DEVCTRL_TSTJ| UOTGHS_DEVCTRL_TSTK|UOTGHS_DEVCTRL_TSTPCKT|UOTGHS_DEVCTRL_OPMODE2) ;
+
+  // Enable USB macro
+  UOTGHS->UOTGHS_DEVCTRL |= UOTGHS_CTRL_USBE;
+
+  // Enable the UID pin select
+  UOTGHS->UOTGHS_DEVCTRL |= UOTGHS_CTRL_UIDE;
+
+  // Enable OTG pad
+  UOTGHS->UOTGHS_DEVCTRL |= UOTGHS_CTRL_OTGPADE;
+
+  // Enable clock OTG pad
+  UOTGHS->UOTGHS_DEVCTRL &= ~UOTGHS_CTRL_FRZCLK;
+
+  // With OR without DMA !!!
+  // Initialization of DMA
+  for( ul=1; ul<= UOTGHSDEVDMA_NUMBER ; ul++ )
+  {
+    // RESET endpoint canal DMA:
+    // DMA stop channel command
+    UOTGHS->UOTGHS_DEVDMA[ul].UOTGHS_DEVDMACONTROL = 0;  // STOP command
+
+    // Disable endpoint
+    UOTGHS->UOTGHS_DEVEPTIDR[ul] = (UOTGHS_DEVEPTIDR_TXINEC|UOTGHS_DEVEPTIDR_RXOUTEC|UOTGHS_DEVEPTIDR_RXSTPEC|UOTGHS_DEVEPTIDR_UNDERFEC|UOTGHS_DEVEPTIDR_NAKOUTEC|
+                                    UOTGHS_DEVEPTIDR_HBISOINERREC|UOTGHS_DEVEPTIDR_NAKINEC|UOTGHS_DEVEPTIDR_HBISOFLUSHEC|UOTGHS_DEVEPTIDR_OVERFEC|UOTGHS_DEVEPTIDR_STALLEDEC|
+                                    UOTGHS_DEVEPTIDR_CRCERREC|UOTGHS_DEVEPTIDR_SHORTPACKETEC|UOTGHS_DEVEPTIDR_MDATEC|UOTGHS_DEVEPTIDR_DATAXEC|UOTGHS_DEVEPTIDR_ERRORTRANSEC|
+                                    UOTGHS_DEVEPTIDR_NBUSYBKEC|UOTGHS_DEVEPTIDR_FIFOCONC|UOTGHS_DEVEPTIDR_EPDISHDMAC|UOTGHS_DEVEPTIDR_NYETDISC|UOTGHS_DEVEPTIDR_STALLRQC);
+
+    // Reset endpoint config
+    UOTGHS->UOTGHS_DEVEPTCFG[ul] = 0UL;
+
+    // Reset DMA channel (Buff count and Control field)
+    UOTGHS->UOTGHS_DEVDMA[ul].UOTGHS_DEVDMACONTROL = 0x02UL;  // NON STOP command
+
+    // Reset DMA channel 0 (STOP)
+    UOTGHS->UOTGHS_DEVDMA[ul].UOTGHS_DEVDMACONTROL = 0UL;  // STOP command
+
+    // Clear DMA channel status (read the register to clear it)
+    UOTGHS->UOTGHS_DEVDMA[ul].UOTGHS_DEVDMASTATUS = UOTGHS->UOTGHS_DEVDMA[ul].UOTGHS_DEVDMASTATUS;
+  }
+
+  UOTGHS->UOTGHS_DEVCTRL |= UOTGHS_CTRL_VBUSTE;
+  UOTGHS->UOTGHS_DEVIER = UOTGHS_DEVIER_WAKEUPES;
+
+  return 0UL ;
+}
+
+void USBD_Attach(void)
+{
+  UOTGHS->UOTGHS_DEVCTRL &= ~(unsigned int)UOTGHS_DEVCTRL_DETACH;
+}
+
+void USBD_Detach(void)
+{
+  UOTGHS->UOTGHS_DEVCTRL |= UOTGHS_DEVCTRL_DETACH;
+}
+
 
 #endif /* SAM3XA_SERIES */