If you ever needed a reason to understand trigonometry, this project may have just given you one. Using an Arduino to control a simple motorised arm with three servos, it can operate a pen a the end of the arm as a very simple dot-matrix printer. However instead of straight lines the arm operates in arcs, due to the design of the arm - similar to an elbow. It's easier to understand when you see it, for example:
The image to draw was captured with an iPhone app, reduced to 100 x 100 pixels and using some more software magic sent to the Arduino. For a complete explanation, Arduino sketch and more - check out the project page. And we're on twitter and Google+, so follow us for news and product updates as well.
So if this sort of project intrigues you and you're new to Arduino, the first step is a solid board for your projects - our Freetronics Eleven - the Arduino-Uno compatible with low-profile USB socket, onboard prototyping space and easy to view LEDs: