To the average e-enthusiast, the RS-232 interface always appears friendlier than the USB port. However, even with a small 8-bit microcontroller, it's easy to implement the USB bus in device mode. The advantages are obvious:

1. You save the cost of a USB/RS232 converter.
2. USB devices such as keyboards can be easily emulated without needing a separate driver, meaning you are able to design a programmable USB keyboard at minimum hardware cost and software effort.

And as you will discover here, our versatile USB Keyboard Stick not only helps to build useful designs — it’s also fun to use by itself!

Two applications 

1. USB Annoy-a-Tron: an essential evil genius tool
2. Masterkey: stay safe like a pro

Download below the article in English, German, French or Dutch, together with the project's firmware.