AnsweredAssumed Answered

stm32f407 USB HID device can miss a report from PC? - I think I need a little advice :)

Question asked by dudas.david on Sep 27, 2015
Hi all,

normally my application sends a report to the host PC when there's any change. The host PC sends 3 types of reports constantly to the device, and I have to answer immediately for one of theese message (with a second type of report). Everything seems fine, but after a couple of minutes something happens :-)

With USBlyzer I can see PC issues an output report but my application running on STM32F4 doesn't process one report correctly? There is no URB Bulk or Interrupt Transfer succeeded Message in USBlyzer for that message and the application on the host PC side gets stuck. I tried to catch whitout much success. I'm sure it's not because a still processed ISR and it's not a HAL_PCD_IS_INVALID_INTERRUPT (the later is not a problem it seems, because I've some during normal operation). Any idea? Is it possible ISR misses it?

It seems this problem always happens when the 16byte long report comes from PC (however before the problem it arrives successfully several times). USBD_CUSTOMHID_OUTREPORT_BUF_SIZE is 16 byte in my code, but I'm not sure if it has any effect.