2015-02-18 01:27 AM
Hi,
I'm using the USB Host library 2.1.0 (with USB_OTG_FS) on an STM32F401CD. Using the USB CDC code I'm having the following issue:When the STM32 is connected to a PC but no application on the PC has the port open, the STM32 gets stuck in an interrupt loop:2015-02-18 01:54 AM
Just stepped through more: you get repeats of 5x DCD_WriteEmptyTxFifo and then 1x usbd_cdc_SOF... But so often that no code can run outside of IRQs.
It appears to happen because right at the start, Handle_USBAsynchXfer has sent some data with DCD_EP_Tx.However, I also use this firmware on an STM32F103 (with the USB library for that) and that does exactly the same thing but is able to keep working perfectly fine.2015-02-20 12:03 AM
Hi Gordon,
It sounds like this reported bug. Good luck !