Using Joysticks In Your Circuits
Older joysticks are basically two potentiometers handling X & Y axes. With these, it is merely a matter of finding the signal inputs and outputs, maybe power supply leads, and perhaps button/switch leads.
Newer joysticks are most typically USB powered and compatible. These are especially useful with Arduino-style microcontrollers.
You will definitely need to do some research on the type of joystick that you are using. Many of the more modern joysticks have detailed datasheets, many of which cater to the DIYer rather than the design engineer.