SerialUSB: A cheap USB proxy for input devices

https://www.electronics-lab.com/serialusb-a-cheap-usb-proxy-for-input-devices/

Serialusb is a cheap (~$5) USB proxy intended to be used with input devices. It is the combination of: a PC software operating the host side of the proxy an atmega32u4 firmware operating the device side of the proxy SerialUSB: A cheap USB proxy for input devices – [Link]