USB Biofeedback Game Controller

Step 14 Hack your Ardunio to load new atmega8u2 firmware

To play video games on your computer with the Arduino, we're going to turn your Arduino into a HID USB keyboard to interface with your computer; to do this you'll need to upload new firmware.

For Mac:
Follow the instructions on this very well put together blog...
Arduino Keyboard HID Part 1
Arduino Keyboard HID Part 2
Latest Hex Files for Uno and Mega 2560

For Windows:
Download the latest hex files
Then follow the instructions on how to upload the hex files to your board using free software called Flip
Upgrading the Arduino Uno 8U2 using Flip

For Linux:
Download the latest hex files
Then follow the instructions on how to upload the hex files to your board
Building Arduino Atmega8u2 firmware on Linux

Note: You'll need to reflash your Arduino with the original firmware to upload new sketches again

Once your Arduino can be connected to your computer and recognized as a HID device, it should be ready to go. Disconnect it and slide it down into your project enclosure.