Ok this is not a project 100% core Arduino, because it uses custom hardware and only the bootloader of Arduino. But Arduino follows the Open-Hardware philosophy, so we are honoured to share this project that use a bit of Arduino. [chris] , from silverball software, sent us his way to build a game controller , programmed with Arduino software.
Well after a few months of tinkering and several designs I finally have one.
The design is based around the Atmega 328 running the Arduino bootloader. There is a RN42-HID bluetooth module that allows serial communication between it and the microprocessor.
I wanted the device to be fully hackable so I designed it with headers for both the bluetooth module and the Atmega 328 chip. I can reprogram the bluetooth module to run HID keyboard or mouse (or combined), it can iterate as a gamepad, or it can reconfigured to run serial protocol and iterate as a virtual com port.
On the [website] there is full description with lots of pictures, have a look.
[original story: Arduino Blog]