“serialusb is a cheap (~$5) USB proxy intended to be used with input devices. Input devices generally use interrupt IN and OUT endpoints, and operate at low or full speed modes. The maximum throughput is 64 kB/s = 512kbps in each direction (1000Hz, 64-byte packets). A USB proxy requires a system with both device and host interfaces. Many ARM boards fulfill this requirement, but those aren’t as cheap (yet).”