The CGS04 is a small mixer that preserved the D.C. component of signals, at audio frequencies and below.
The Joystick Controller Hardware Kit does not include the joystick and will require 2x CGS04 PCB and Component Kits. Some additional resistors will be rquired to complete the Controller.
CGS04 Datasheet and Build Guide
CGS04 Joystick Datasheet and Build Guide