Quadros Systems, Inc. | Embedded USB Host - Quadros Systems, Inc.
GitHub - weston-embedded/uC-USBH: Efficient USB host stack for embedded systems equipped with a USB host or OTG controller. Includes many class drivers such as MSC, HID, CDC-ACM, and USB2Ser.
USB Host Stack
PDF] HID Architecture and Design in Embedded USB Host System | Semantic Scholar