diff --git a/hardware/arduino/sam/cores/sam/USB/USBCore.cpp b/hardware/arduino/sam/cores/sam/USB/USBCore.cpp
index 20793afae..d2007a12c 100644
--- a/hardware/arduino/sam/cores/sam/USB/USBCore.cpp
+++ b/hardware/arduino/sam/cores/sam/USB/USBCore.cpp
@@ -16,18 +16,18 @@
 
 #include "Arduino.h"
 
-const uint8_t _initEndpoints[] =
+const uint32_t _initEndpoints[] =
 {
-	0,
+	EP_TYPE_CONTROL,
 
 #ifdef CDC_ENABLED
-	EP_TYPE_BULK_IN,			// CDC_ENDPOINT_IN
-	EP_TYPE_BULK_OUT,			// CDC_ENDPOINT_OUT
-	EP_TYPE_INTERRUPT_IN,		// CDC_ENDPOINT_ACM
+	EP_TYPE_BULK_IN,                // CDC_ENDPOINT_IN
+	EP_TYPE_BULK_OUT,               // CDC_ENDPOINT_OUT
+	EP_TYPE_INTERRUPT_IN,           // CDC_ENDPOINT_ACM
 #endif
 
 #ifdef HID_ENABLED
-	EP_TYPE_INTERRUPT_IN		// HID_ENDPOINT_INT
+	EP_TYPE_INTERRUPT_IN_HID        // HID_ENDPOINT_INT
 #endif
 };
 
diff --git a/hardware/arduino/sam/cores/sam/build_gcc/libarduino_arduino_due_x.mk b/hardware/arduino/sam/cores/sam/build_gcc/libarduino_arduino_due_x.mk
index 5867a5f61..736f8df23 100644
--- a/hardware/arduino/sam/cores/sam/build_gcc/libarduino_arduino_due_x.mk
+++ b/hardware/arduino/sam/cores/sam/build_gcc/libarduino_arduino_due_x.mk
@@ -161,6 +161,9 @@ $(addprefix $(OUTPUT_PATH)/,$(C_OBJ)): $(OUTPUT_PATH)/%.o: %.c
 #	"$(CC)" -v -c $(CFLAGS) $< -o $@
 	@"$(CC)" -c $(CFLAGS) $< -o $@
 
+#$(addprefix $(OUTPUT_PATH)/,$(CPP_OBJ)): $(OUTPUT_PATH)/%.d: %.o
+#	"$(CC)" -M -MF $@.d -c $(CPPFLAGS) $<
+
 $(addprefix $(OUTPUT_PATH)/,$(CPP_OBJ)): $(OUTPUT_PATH)/%.o: %.cpp
 	"$(CC)" -xc++ -c $(CPPFLAGS) $< -o $@
 #	@"$(CC)" -xc++ -c $(CPPFLAGS) $< -o $@
diff --git a/hardware/arduino/sam/system/libsam/include/uotghs.h b/hardware/arduino/sam/system/libsam/include/uotghs.h
index 131cfdc95..4b0f2c7a1 100644
--- a/hardware/arduino/sam/system/libsam/include/uotghs.h
+++ b/hardware/arduino/sam/system/libsam/include/uotghs.h
@@ -24,23 +24,23 @@
 
 
 // Control Endpoint
-#define EP_TYPE_CONTROL           (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_CTRL | UOTGHS_DEVEPTCFG_EPBK_1_BANK)
+#define EP_TYPE_CONTROL           (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_CTRL | UOTGHS_DEVEPTCFG_EPBK_1_BANK | UOTGHS_DEVEPTCFG_NBTRANS_1_TRANS)
 
 // 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
+//#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 | UOTGHS_DEVEPTCFG_NBTRANS_1_TRANS)
+#define EP_TYPE_BULK_OUT          (UOTGHS_DEVEPTCFG_EPSIZE_512_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_BLK | UOTGHS_DEVEPTCFG_EPBK_2_BANK | UOTGHS_DEVEPTCFG_NBTRANS_1_TRANS)
+#define EP_TYPE_INTERRUPT_IN      (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPDIR_IN | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPBK_2_BANK | UOTGHS_DEVEPTCFG_NBTRANS_1_TRANS)
+//#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
+//#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 | UOTGHS_DEVEPTCFG_NBTRANS_1_TRANS)
+//#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)
+#define EP_TYPE_INTERRUPT_OUT		  (UOTGHS_DEVEPTCFG_EPSIZE_64_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPTYPE_INTRPT | UOTGHS_DEVEPTCFG_EPBK_1_BANK | UOTGHS_DEVEPTCFG_NBTRANS_1_TRANS)
+#define EP_TYPE_ISOCHRONOUS_IN		(UOTGHS_DEVEPTCFG_EPSIZE_1024_BYTE | UOTGHS_DEVEPTCFG_EPDIR_IN | UOTGHS_DEVEPTCFG_EPTYPE_ISO | UOTGHS_DEVEPTCFG_EPBK_3_BANK | UOTGHS_DEVEPTCFG_NBTRANS_3_TRANS)
+#define EP_TYPE_ISOCHRONOUS_OUT		(UOTGHS_DEVEPTCFG_EPSIZE_1024_BYTE | UOTGHS_DEVEPTCFG_EPTYPE_ISO | UOTGHS_DEVEPTCFG_EPBK_3_BANK | UOTGHS_DEVEPTCFG_NBTRANS_3_TRANS)
 
 #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 19ddffb23..04c640b89 100644
--- a/hardware/arduino/sam/system/libsam/source/uotghs.c
+++ b/hardware/arduino/sam/system/libsam/source/uotghs.c
@@ -20,21 +20,23 @@
 
 #if SAM3XA_SERIES
 
-void USBD_InitEndpoints( uint8_t* puc_EndPoints, uint32_t ul_EndPoints )
+void USBD_InitEndpoints( uint32_t* puc_EndPoints, uint32_t ul_EndPoints )
 {
-	for (uint8_t i = 1; i < sizeof(_initEndpoints); i++)
+  uint32_t ul_EP ;
+
+	for (ul_EP = 1; ul_EP < sizeof(_initEndpoints); ul_EP++)
 	{
     // Reset Endpoint Fifos
-    UOTGHS->UOTGHS_DEVEPTISR[i].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_TOGGLESQ | UDPHS_EPTCLRSTA_FRCESTALL;
-    UOTGHS->UDPHS_EPTRST = 1<<i;
+    UOTGHS->UOTGHS_DEVEPTISR[ul_EP].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_TOGGLESQ | UDPHS_EPTCLRSTA_FRCESTALL;
+    UOTGHS->UOTGHS_DEVEPT = 1<<ul_EP;
 
 		//UECONX = 1;
-		//UECFG0X = pgm_read_byte(_initEndpoints+i);
-        UOTGHS->UDPHS_EPT[i].UDPHS_EPTCFG = _initEndpoints[i];
+		//UECFG0X = pgm_read_byte(_initEndpoints+ul_EP);
+        UOTGHS->UDPHS_EPT[ul_EP].UDPHS_EPTCFG = _initEndpoints[ul_EP];
 
-        while( (signed int)UDPHS_EPTCFG_EPT_MAPD != (signed int)((UOTGHS->UDPHS_EPT[i].UDPHS_EPTCFG) & (unsigned int)UDPHS_EPTCFG_EPT_MAPD) )
+        while( (signed int)UDPHS_EPTCFG_EPT_MAPD != (signed int)((UOTGHS->UDPHS_EPT[ul_EP].UDPHS_EPTCFG) & (unsigned int)UDPHS_EPTCFG_EPT_MAPD) )
         ;
-        UOTGHS->UDPHS_EPT[i].UDPHS_EPTCTLENB = UDPHS_EPTCTLENB_EPT_ENABL;
+        UOTGHS->UDPHS_EPT[ul_EP].UDPHS_EPTCTLENB = UDPHS_EPTCTLENB_EPT_ENABL;
 
         //		UECFG1X = EP_DOUBLE_64;
 	}