Posted on April 04, 2016 at 17:51Hi sturmer,
> Way to be notified on CDC transmit complete? a) Poll ((USBD_CDC_HandleTypeDef*)(USBD_Device.pClassData))->TxState value in your application code
- While transfer is going on, TxState is kept in 1
- When transfer completes, TxState goes to 0 (see code below)
OR
b) Modify CDC class code, to add your custom callback, which is called at transfer completion interrupt.
\STM32Cube_FW_F4_V1.11.0\Middlewares\ST\STM32_USB_Device_Library\Class\CDC\Src\
usbd_cdc.c
// line 664
static uint8_t USBD_CDC_DataIn (USBD_HandleTypeDef *pdev, uint8_t epnum)
{
USBD_CDC_HandleTypeDef *hcdc = (USBD_CDC_HandleTypeDef*) pdev->pClassData;
if(pdev->pClassData != NULL)
{
hcdc->TxState = 0;
// <---------------- add your custom callback here.
return USBD_OK;
}
else
{
return USBD_FAIL;
}
}
> so I know as soon as possible when I can send the next packet? You don't need to split large buffer into chunks.
You may pass ANY size of data buffer to USBD_CDC_SetTxBuffer(), even greater than MPS (Max Packet Size: FS 64 bytes / HS 512 bytes). The device stack automatically splits the buffer into MPS transactions, and it sends them one by one.
When you are starting on an existing ''CDC_Standalone'' project, instead of generated code by CubeMX, this project implements a periodic timer to keep TX (device->host) transfer. This timer is good for USB-UART application to keep transfer speed (size) over slow UART with fast USB. But for other applications, this timer ISR causes unexpected result. And then, delete this timer initialization and its ISR (HAL_TIM_PeriodElapsedCallback())
usbd_cdc_interface.c
static int8_t CDC_Itf_Init(void)
{
...
// line 120 Delete these timer setting lines
/*##-3- Configure the TIM Base generation #################################*/
TIM_Config();
/*##-4- Start the TIM Base generation in interrupt mode ####################*/
/* Start Channel1 */
if(HAL_TIM_Base_Start_IT(&TimHandle) != HAL_OK)
{
/* Starting Error */
Error_Handler();
}
Tsuneo
> to ST web admin,
''Format Code Block'' button doesn't work with ''Web.config registration missing'' error. Please fix it.
