2021-09-28 07:13 PM
I used ThreadX and USBX in the project. When I only use USB as a HID Device, STM32 can transmit data to the PC 1000 times per second, but when I use USB as a CDC+HID composite device, the transmission frequency of HID is greatly reduced. Will increasing the CDC only 10 times per second affect the transmission frequency of HID? Why is there such a phenomenon?
2021-09-28 08:23 PM
Check the HID polling interval parameter in the device HID descriptor.
2021-09-28 08:45 PM
HID polling interval parameter is 1ms
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2021-09-29 08:07 AM
Try 11 ms (while waiting for better answers)
2021-09-29 05:51 PM
The delay of 11ms is too long to meet the design requirements. The strange thing is that the same program works very well on STM32H7, but it won’t work on STM32F1.
2021-09-30 09:36 AM
Note that all functions and endpoints of a composite device share one hub port's bandwidth.
IIRC minimal valid polling interval of full-speed HID device is not 1 ms.
Is your STM32H7 USB controller in high speed mode?
2021-10-06 11:39 PM