Hello ST Team,
I developped a USB OTG FS in CDC class, using advices from ST's tutorials in Youtube and I managed to send data received from the USB reception buffer to another one I want to use for I2C communication.
However, when I enable the I2C1 and generate the code thanks to STM32CubeIDE, I can't communicate with the VCP anymore.
Please find below the code I typed. It is working well.
In usbd_cdc_if.c :
At the beginning of the file
/*
* USB Reception Buffer
* */
extern uint8_t UserRxBuffer[];[...] // Nothing changed between
/*
* Réception function
**/
static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
{
/* USER CODE BEGIN 6 */
USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]); //Already present in the generated code
USBD_CDC_ReceivePacket(&hUsbDeviceFS); //Already present in the generated code
strlcpy(UserRxBuffer,Buf,(*Len)+1); //Data received stored in the réception buffer
return (USBD_OK);
/* USER CODE END 6 */
}
/*
* Transmission function
**/
uint8_t CDC_Transmit_FS(uint8_t* Buf, uint16_t Len)
{
uint8_t result = USBD_OK; //Already present in the generated code
/* USER CODE BEGIN 7 */
USBD_CDC_HandleTypeDef *hcdc = (USBD_CDC_HandleTypeDef*)hUsbDeviceFS.pClassData; //Already present in the generated code
/*
* Condition already present in the generated code
**/
if (hcdc->TxState != 0){
return USBD_BUSY;
}
USBD_CDC_SetTxBuffer(&hUsbDeviceFS, Buf, Len); //Data to send stored in the transmission buffer
result = USBD_CDC_TransmitPacket(&hUsbDeviceFS); //Transmit data stored in the transmission buffer
/* USER CODE END 7 */
return result;
}[...] // Nothing changed after
In main.c :
At the beginning of the file
/*
* Message to store in the USB transmission buffer
*/
uint8_t UserTxBuffer[2048]="Hello ";
/*
* USB reception buffer
*/
uint8_t UserRxBuffer[2048];
/*
* I2C data storage buffer
*/
uint8_t I2CBuffer[]="00";
uint8_t OK_Flag=0;int main(void)
{
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
MX_GPIO_Init();
MX_USB_DEVICE_Init();
while (1)
{
/*
* Transmit data to USB OTG FS port
*/
USBD_CDC_SetTxBuffer(&hUsbDeviceFS, UserTxBuffer, sizeof(UserTxBuffer));
USBD_CDC_TransmitPacket(&hUsbDeviceFS);
/*
* Receive data from USB OTG FS port
*/
if(UserRxBuffer[0]==0x59) //When the first character is a 'Y'
{
OK_Flag = 1; //Set the flag at 1
memcpy(I2CBuffer,UserRxBuffer+1,2); //Copy the data in the I2C buffer
}
HAL_Delay(1000);
}[...] Nothing changed after
All the code which has not been changed has been generated thanks to the STM32CubeMX integrated in the STM32CubeIDE.
When I use Realterm, I have the following data received by the PC:
When I send data to the MCU with RealTerm (e.g. the string "YOP") :
Using the debugger, I suspend the process and watch the data, which have been received:
However, as soon as I enable the I2C, I can't communicate with RealTerm anymore (I also tried Putty with the same results).
However, the PC still detect the VCP as it can be seen in the screenshot of the device manager below :
It's not a part of my code which have been deleted by the STM32CubeIDE, since as soon as I disable again the I2C communication and generate the code again, the communication is working fine again.
Is there anyone who experienced it before and who could tell me what I'm missing here?
Thanks for your help!
