Software Installation
You can now use the 16u2 as normal Arduino USB board like a Leonardo/Micro/Teensy with the Arduino IDE. Therefore you need to get some software and install it properly. Arduino IDE 1.6.6 or higher is required.
You have to install new drivers for the 8/16/32u2 if you want to use its USB functions. This is because it uses different USB PID/VIDs to enumerate as different device like the Leonardo for example.
This is not required for the 32u4 or Windows10/Mac/Linux users.
Before I used an own driver file named HoodLoader2.inf, but there are some problems with unsigned drivers under Windows8. To install a signed driver instead please use the Teensy driver which works for every USB Serial device.
The Teensy driver recognizes any CDC USB device as "Teensy USB-Serial" (and not as HoodLoader2) if no other driver is installed. This is also useful if you plan to change the PID/VID for developing.
####a) Installation via Boards Manager See this Adafruit tutorial on how to install additional boards/cores. Instead of using their .json url use this one:
####b) Manual Installation To get the 16u2 board definitions for uploading, copy this HoodLoader2 folder into your sketchbook like this: sketchbook/hardware/HoodLoader2/ Remove the '-master' postfix.
Arduino IDE 1.6.6 added support for the u2 Series. You can download it from here. Currently you need to download the hourly build to get 1.6.6.
You should now have installed the bootloader itself, drivers, HL2 board definitions and the newest IDE. Continue reading with the getting started page.