Learning About Capacitive Proximity Sensing By Building A Theremin
Capacitive proximity sensing is a method to determine how close two items are to each other. In many cases, it is used in user interfaces to measure the distance a finger is from a sensor. Capacitive sensing is useful in many applications because it provides an input method with no moving parts.
Often when learning a new technology, it helps to have a project in mind that is simple enough that the majority of design and troubleshooting is directly related to implementing the technology. It can also help keep an engineer’s drive going when the project is interesting and exciting. To this end, this TechNote describes how to make a rudimentary Theremin – a musical instrument with two controls: pitch (frequency) and volume (amplitude) – to illustrate the basics of working with capacitive sensing. At the end of this TechNote, you’ll find a list of parts, several reference sources, and a link for downloading the software you’ll need.
...download complete article here (144 KB PDF)