Over the weekend I built a simple counting device using a switch, a PIC chip, and a seven segment display. On the PIC, I used edge detection to trap the button press event. It's been interesting learning about physical interaction, especially coming at it with my background in software interaction design. Its funny because I tend to think in terms of button press events and software constructs. The ideas are perfectly valid in terms of an approach to learning physical interaction. However, there is a bit of translation. Or, it's possible that software based interaction is abstract in the sense that there is no physical button so, we use terms like 'button press event' to describe the action of pressing a button.

Learning how to use edge detection is important because often times you don't want to know if sensor is on or off, rather you want to know if the sensor was triggered or reached a certain value. The documentation and PIC code are up in the Physical computing section. I also posted the tricolor LED and DC motor labs as well.