Ok, let me see if I can explain:
I have a Pi3 with the Pi 7 inch capacitive touch screen. I am using Python and Kivy to create a GUI that I would like to send key-presses to a windows machine as a keyboard and/or game controller. I would also like to incorporate real-world hardware (encoders, switches, LEDs) thru the GPIO. I would like this to happen via USB. I do not want to use wifi (VNC). Bluetooth would be ok if it would be the only and/or best way, but really I'd like to keep things wired for my application.
I am aware that I can not use the USB ports due to the architecture of the USB BUS, but is there some way to use the GPIO?
Should I use, say, I2C with an Arduino nano which can be loaded to act as an USB HID?
I've been struggling with this for a minute and any advice would be helpful.