diff --git a/stmhal/usb.c b/stmhal/usb.c
index 5ba5ddc6e7..ac85c53714 100644
--- a/stmhal/usb.c
+++ b/stmhal/usb.c
@@ -607,7 +607,11 @@ STATIC mp_obj_t pyb_usb_hid_send(mp_obj_t self_in, mp_obj_t report_in) {
     }
 
     // send the data
-    USBD_HID_SendReport(&hUSBDDevice, bufinfo.buf, bufinfo.len);
+    if (USBD_OK == USBD_HID_SendReport(&hUSBDDevice, bufinfo.buf, bufinfo.len)) {
+        return mp_obj_new_int(bufinfo.len);
+    } else {
+        return mp_obj_new_int(0);
+    }
 #endif
 
     return mp_const_none;
diff --git a/stmhal/usbd_hid_interface.c b/stmhal/usbd_hid_interface.c
index 04f1b7fd0c..837feece9d 100644
--- a/stmhal/usbd_hid_interface.c
+++ b/stmhal/usbd_hid_interface.c
@@ -45,21 +45,35 @@
 
 /* Private variables ---------------------------------------------------------*/
 
-static __IO uint8_t dev_is_connected = 0; // indicates if we are connected
-
 static uint8_t buffer[2][HID_DATA_FS_MAX_PACKET_SIZE]; // pair of buffers to read individual packets into
 static int8_t current_read_buffer = 0; // which buffer to read from
-static uint32_t last_read_len; // length of last read
+static uint32_t last_read_len = 0; // length of last read
 static int8_t current_write_buffer = 0; // which buffer to write to
 
-
 /* Private function prototypes -----------------------------------------------*/
+static int8_t HID_Itf_Init     (void);
 static int8_t HID_Itf_Receive  (uint8_t* pbuf, uint32_t Len);
 
 const USBD_HID_ItfTypeDef USBD_HID_fops = {
+    HID_Itf_Init,
     HID_Itf_Receive
 };
 
+/**
+  * @brief  HID_Itf_Init
+  *         Initializes the HID media low layer
+  * @param  None
+  * @retval Result of the opeartion: USBD_OK if all operations are OK else USBD_FAIL
+  */
+static int8_t HID_Itf_Init(void)
+{
+    current_read_buffer = 0;
+    last_read_len = 0;
+    current_write_buffer = 0;
+    USBD_HID_SetRxBuffer(&hUSBDDevice, buffer[current_write_buffer]);
+    return USBD_OK;
+}
+
 /**
   * @brief  HID_Itf_Receive
   *         Data received over USB OUT endpoint is processed here.
diff --git a/stmhal/usbdev/class/inc/usbd_cdc_msc_hid.h b/stmhal/usbdev/class/inc/usbd_cdc_msc_hid.h
index 76a7678929..7cb64fd845 100644
--- a/stmhal/usbdev/class/inc/usbd_cdc_msc_hid.h
+++ b/stmhal/usbdev/class/inc/usbd_cdc_msc_hid.h
@@ -48,6 +48,7 @@ typedef struct {
 } USBD_CDC_HandleTypeDef;
 
 typedef struct _USBD_HID_Itf {
+  int8_t (* Init)   (void);
   int8_t (* Receive)(uint8_t *, uint32_t);
 } USBD_HID_ItfTypeDef;
 
diff --git a/stmhal/usbdev/class/src/usbd_cdc_msc_hid.c b/stmhal/usbdev/class/src/usbd_cdc_msc_hid.c
index d136570234..3ebc7d8280 100644
--- a/stmhal/usbdev/class/src/usbd_cdc_msc_hid.c
+++ b/stmhal/usbdev/class/src/usbd_cdc_msc_hid.c
@@ -724,6 +724,8 @@ static uint8_t USBD_CDC_MSC_HID_Init(USBD_HandleTypeDef *pdev, uint8_t cfgidx) {
                        USBD_EP_TYPE_INTR,
                        mps_out);
 
+        HID_fops->Init();
+
         // Prepare Out endpoint to receive next packet
         USBD_LL_PrepareReceive(pdev, hid_out_ep, HID_ClassData.RxBuffer, mps_out);