Hi, I have a STM32F401CBU6 custom board configured as USB host and connected to APC UPS HID device. My custom board is identical to the Disco411 kit.

[PSaba]

When connected and detached the APC UPS device, my STM32 code is able to trigger the HOST_DEV_ATTACHED and HOST_DEV_DISCONNECTED events.

After HOST_DEV_ATTACHED and HOST_ENUMERATION events, In HOST_CHECK_CLASS, I have added code to sent a character to APC UPS from STM32 USB host using

status=USBH_HID_SetReport(phost,0x02,0x00,'Y',1);

The status is always coming as USBH_BUSY.

What could be the reason?? Any ideas or pointers will help me.

Regards,

Pradeep