You could add PJRC's Teensy boards to the I/O list.
www.pjrc.com/teensyI've been using them to make custom hardware for X-Plane. You can use them in three ways:
- as a joystick controller, sending axis positions and button presses to the computer like a normal joystick
- as an Arduino-compatible project board, connecting to the simulator via the USB serial port
- connecting directly to X-Plane (over the serial port) via libraries included with the IDE. This makes it incredibly simple to build X-Plane custom hardware.
The Teensy boards are Arduino-compatible, but superior to Arduino in how they connect to the computer - integrated USB or something, I don't understand it myself
So they can do stuff Arduino can't do.
Also they're incredibly cheap. Possibly not as good as a dedicated joystick control board like the ones made by Leo Bodnar, based on the generalisation that a multi-purpose device is inferior to the specialised device. But I haven't checked this for myself!
