Isochronous transfer from USB webcam

[KWata.13]

Hi, I'm going to get images from usb webcam with STM32F746Disco.

I implemented the code based on the information in the forums discussed in the past.

The usb host mode is FS and my usb cam works in FS mode.

The processes of getting the frame type, the format type, and probing the control, committing the control, alternate setting are worked.

But USBH_IsocReceiveData doesnot worked and got the err of USB_OTG_HCINT_TXERR and USB_OTG_HCINT_CHH, the USBH_LL_GetLastXferSize is zero.

Please tell me where the problem is.

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All the code is here.

https://github.com/meerstern/STM32F746G_DISCO_UVC_HOST

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Main point core is here.

https://github.com/meerstern/STM32F746G_DISCO_UVC_HOST/blob/main/Middlewares/ST/STM32_USB_Host_Library/Class/UVC/Src/usbh_uvc.c

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Thanks.

[Walid ZRELLI]

Hello @KWata.13​ 

Actually we provide an audio example for isochronous OUT transfer to stream audio from PC to STM32.

Check the following example and try to adapt it to your use case :

• Path: Projects\STM32H743I-EVAL\Applications\USB_Device\Audio_Standalone

This could help you.

BeST Regards,

Walid