Bonus Practical Example: The ADK Paper Piano

You have seen that building a simple DIY capacitive touch sensor is neither hard nor expensive. As you can easily imagine, this technique is used a lot in the hobby community to build projects with beautiful and cool interactive user interfaces. To get your own creative juices flowing, I want to take this opportunity to show you one of my projects that I realized for the Google Developer Day 2011 in Berlin as just one example of what can be achieved.

In July 2011, Google announced the Open Call for Google Developer Day. Google Developer Day is Google's biggest developer conference outside of the US. It is hosted in several big cities across the globe. The venues for 2011 were Argentina, Australia, Brazil, Czech Republic, Germany, Israel, Japan, and Russia. The Open Call gives developers the opportunity to showcase their skills and projects to an audience of about 2000 developers. Two challenges were part of the Open Call: the HTML5 Challenge and the ADK Challenge. Participants first had to answer some basic questions about the corresponding technology of their challenge. When they successfully answered the questions, they were eligible for round 2 of the challenge. Now, I don't know ho....