diff --git a/usb_endp.c b/usb_endp.c
new file mode 100644
--- /dev/null
+++ b/usb_endp.c
@@ -0,0 +1,76 @@
+/**
+  ******************************************************************************
+  * @file    usb_endp.c
+  * @author  MCD Application Team
+  * @version V4.0.0
+  * @date    21-January-2013
+  * @brief   Endpoint routines
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
+  *
+  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
+  * You may not use this file except in compliance with the License.
+  * You may obtain a copy of the License at:
+  *
+  *        http://www.st.com/software_license_agreement_liberty_v2
+  *
+  * Unless required by applicable law or agreed to in writing, software 
+  * distributed under the License is distributed on an "AS IS" BASIS, 
+  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  * See the License for the specific language governing permissions and
+  * limitations under the License.
+  *
+  ******************************************************************************
+  */
+
+
+/* Includes ------------------------------------------------------------------*/
+#include "usb_lib.h"
+#include "usb_desc.h"
+#include "usb_mem.h"
+#include "hw_config.h"
+#include "usb_istr.h"
+#include "usb_pwr.h"
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+
+/* Interval between sending IN packets in frame number (1 frame = 1ms) */
+#define VCOMPORT_IN_FRAME_INTERVAL             5
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+extern __IO uint8_t Receive_Buffer[64];
+uint32_t Receive_length;
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/*******************************************************************************
+* Function Name  : EP1_IN_Callback
+* Description    :
+* Input          : None.
+* Output         : None.
+* Return         : None.
+*******************************************************************************/
+
+void EP1_IN_Callback (void)
+{
+  set_packet_sent();
+}
+
+/*******************************************************************************
+* Function Name  : EP3_OUT_Callback
+* Description    :
+* Input          : None.
+* Output         : None.
+* Return         : None.
+*******************************************************************************/
+void EP3_OUT_Callback(void)
+{
+  set_packet_receive();
+  Receive_length = GetEPRxCount(ENDP3);
+  PMAToUserBufferCopy((unsigned char*)Receive_Buffer, ENDP3_RXADDR, Receive_length);
+}
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/