Comment by bb88

You can use two arduinos and connect them in such a way they are talking through the GPIO ports to each other.

You could do something similar with a couple of Raspberry Pi's or RPI nanos. It doesn't really matter as both can be configured as USB devices and to access their GPIO ports.

The trick is getting them to act as a USB device and then to have them send data over the GPIO ports.

Fortunately I don't think either of those should be super hard.