Hi All,
I'm building an instrument that needs to stream data to a PC at ~4Mbps. People were claiming nearly twice this with USB CDC so I chose the nucleo-h533 board and started with the Ux_Device_CDC_ACM example. I disconnected the USART code and added a loop that calls ux_device_class_cdc_acm_write and then I measure the rate at which I receive data on the PC. I can't get past ~1.8Mbps.
I have tried the following:
- varying the size of the buffer passed in from 64 to 2048
- enabling ZERO copy in the driver UX_DEVICE_ENDPOINT_BUFFER_OWNER=1 and defining UX_DEVICE_CLASS_CDC_ACM_ZERO_COPY
- setting USBD_CDCACM_EPINCMD_FS_BINTERVAL to 1 instead of 5
In all cases, the baud rate remains about the same at 1.8Mbps. Is there anything I can do to improve this?
Best,
Marc
