Awesome

This is simple Go driver for AVT414 USB I/O card. It is PIC16F877 based system with 22 I/O ports and up to 8 ADC ports.

You can buy it on the Polish market (try http://allegro.pl or http://sklep.avt.pl/)

See http://ep.com.pl/files/4241.pdf (Polish but contains some shemes).