make it work!

USB_DEVICE/App/usbd_cdc_if.c

@@ -22,6 +22,7 @@
 #include "usbd_cdc_if.h"
 
 /* USER CODE BEGIN INCLUDE */
+#include "i2c_gateway.h"
 
 /* USER CODE END INCLUDE */
 
@@ -259,11 +260,12 @@ static int8_t CDC_Control_FS(uint8_t cmd, uint8_t* pbuf, uint16_t length)
 static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
 {
   /* USER CODE BEGIN 6 */
-  printf("Rx %d b\r\n", (int) *Len);
-  printf("Bytes: %.*s\r\n", (int) *Len, Buf);
+
+  i2c_command(Buf, *Len);
 
   USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
   USBD_CDC_ReceivePacket(&hUsbDeviceFS);
+
   return (USBD_OK);
   /* USER CODE END 6 */
 }

USB_DEVICE/App/usbd_cdc_if.h

@@ -51,6 +51,7 @@
 #define APP_RX_DATA_SIZE  1000
 #define APP_TX_DATA_SIZE  1000
 /* USER CODE BEGIN EXPORTED_DEFINES */
+extern uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];
 
 /* USER CODE END EXPORTED_DEFINES */