USBKeyboard is a library for the Arduino IDE. It adds HID USB keyboard functionality to your projects, allowing Arduinos and other AVRs to act as a HID USB Devices.
Due to its HID protocol no drivers have to be installed, the USB keyboard connection will work with every PC and OS.

Connect your Arduino to the USB connector following the given schematic below and add a pushbutton betwen D7 and GND. Copy this repository into your libraries folder and (re)start the Arduino IDE.
Open File > Examples > USBKeyboard > USBKeyboard_GettingStarted and upload it to your Arduino.
Unplug your Arduino from your PC and plug in the USB connector. The keyboard should be recognized automatically by your PC, open a text editor of your choice and push the button afterwards, a message will be typed in.

You just need the zener diodes if your Arduino/AVR is running above 3.6V
(following the USB specification 3.6V is the maximum for D+ and D-).

This library is based on the V-USB code by Objective Developement.

As the V-USB code, this library is licensed under GNU GPLv3, see LICENSE.txt for further information.