STM32F0 USB CDC_Init_FS() and CDC_Receive_FS() using CubeMX - c

Question

I am using this code to capture data over the USB. The top code crashes the program once a character is received. The bottom works just fine, although I cannot save the data as I want. The top crashes (endless loop) even before calling CDC_Receive_FS()...which is never called. The bottom calls CDC_Receive_FS() as expected.
For the life of me, I cannot see what is wrong with how I am calling my struct that holds an array of buffers that I loop through.
/* Send Data over USB CDC are stored in this buffer */
uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];
#define MAX_COMMANDS_IN_BUFFER 10 //max commands that can be received and saved without overwriting. Each command has a max size of APP_RX_DATA_SIZE
/* Define size for the receive and transmit buffer over CDC */
/* It's up to user to redefine and/or remove those define */
#define APP_RX_DATA_SIZE 256
#define APP_TX_DATA_SIZE 256
uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];
static struct
{
uint32_t Buffer_Number_Receiving, Buffer_Number_Processing; //Buffer_Number_Receiving is the current position in buffer to receive incoming data. Buffer_Number_Processing is the index of buffer which is being processed.
uint8_t IsCommandDataReceived; // > 0 , data were received. 0 means no data is available
uint8_t UserRxBufferFS[MAX_COMMANDS_IN_BUFFER][APP_RX_DATA_SIZE];//it could save <MaxCommandsInBuffer> number of commands
uint8_t CommandsLens[MAX_COMMANDS_IN_BUFFER]; //save the len of each command
} s_RxBuffers;
static int8_t CDC_Init_FS(void)
{
hUsbDevice_0 = &hUsbDeviceFS;
/* USER CODE BEGIN 3 */
/* Set Application Buffers */
USBD_CDC_SetTxBuffer(hUsbDevice_0, UserTxBufferFS, 0);
USBD_CDC_SetRxBuffer(hUsbDevice_0, s_RxBuffers.UserRxBufferFS[s_RxBuffers.Buffer_Number_Receiving] );//Set the buffer to receive incoming data
USBD_CDC_ReceivePacket(hUsbDevice_0);
return (USBD_OK);
/* USER CODE END 3 */
}
This does not:
/* Received Data over USB are stored in this buffer */
uint8_t UserRxBufferFS[APP_RX_DATA_SIZE];
/* Send Data over USB CDC are stored in this buffer */
uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];
static int8_t CDC_Init_FS(void)
{
hUsbDevice_0 = &hUsbDeviceFS;
/* USER CODE BEGIN 3 */
/* Set Application Buffers */
USBD_CDC_SetTxBuffer(hUsbDevice_0, UserTxBufferFS, 0);
USBD_CDC_SetRxBuffer(hUsbDevice_0, UserRxBufferFS);
USBD_CDC_ReceivePacket(hUsbDevice_0);
return (USBD_OK);
}
Loop
The line here (the use of this buffer) seems to be the culprit:
USBD_CDC_SetRxBuffer(hUsbDevice_0, s_RxBuffers.UserRxBufferFS[s_RxBuffers.Buffer_Number_Receiving] );//Set the buffer to receive incoming data
Any help/insight would be greatly appreciated.

Answer 1

I would make the Rx_Buffer monodimensional and handle the command history separatly.
static struct
{
uint32_t Buffer_Number_Receiving, Buffer_Number_Processing; //Buffer_Number_Receiving is the current position in buffer to receive incoming data. Buffer_Number_Processing is the index of buffer which is being processed.
uint8_t IsCommandDataReceived; // > 0 , data were received. 0 means no data is available
uint8_t UserRxBufferFS[APP_RX_DATA_SIZE];
uint8_t CommandsLens[MAX_COMMANDS_IN_BUFFER]; //save the len of each command
} s_RxBuffers;
Apart from this, since you are usinc a struct (s_RxBuffers type), I think you are not passing the buffer as a pointer in the right way to your function.
I think you should do something like this:
USBD_CDC_SetRxBuffer(hUsbDevice_0, &s_RxBuffers.UserRxBufferFS[0] );//Set the buffer to receive incoming data