A very quick and dirty introduction to
Sensors, Microcontrollers, and Electronics

Part One: some basic definitions

Why do I care about this?

If you're interested in building your own electronic instruments, sculpture, interfaces, tools, etc., then you need to learn about sensors, actuators, microcontrollers, ohms law and other fun things. What you don't need is a degree in electrical engineering. While EE can be a giant and scary field, most of what you need to know to start building things is pretty un-mysterious.

What's a microcontroller?

A microcontroller is a tiny, mostly self-contained computer. They're generally slow (~8Mhz) and have no monitor, no keyboard, little RAM, etc. Most microcontrollers have a number of digital inputs and outputs. Some have other types of i/o as well.

What's a microcontroller good for?

Microcontrollers are good for getting signals from the "real world" into a computer and conversely, for sending digital signals from the computer out into the "real world". The soundcard or graphics card in your computer, for instance, generally contains a microcontroller of some sort. A computer mouse has a microcontroller in it, as does a keyboard, a wacom tablet, a MIDI fader box, etc.

What's a transducer?

A transducer changes one form of energy or information into another form of energy or information. You need to use some sort of transducer to make use of the input/output capabilities of a microcontroller. Some examples of transducers:

Microcontrollers can have a variety of input/output devices that either are or can be hooked up to transducers: As you can see, transducers are everywhere. Information is also everywhere. The trick to using all of this stuff together is to figure out what kind of information you want to capture, how you're going to capture it and move it between domains, and finally what you're going to do with it once you've got it where you want it.

What's a sensor?

Very generally, a sensor is any sort of transducer that helps you to get information about the "real world" into a system. A mouse senses hand movements and button clicks and transmits that information to your computer. A light switch "senses" whether you want the lights to be on or off and transmits that information to your lighting circuits. While there are many types of sensors, most of the ones we'll be interested in are into just a couple of categories. Here are some of the general types of sensors that are useful for art and music making:

What's an actuator?

An actuator is sort of the opposite of a sensor. Think of a doorbell. The button is a sensor that determines when someone wants to ring the bell. The clacker is the actuator that does the ringing. Generally we'll say that an actuator is a transducer that helps you get information from a system out into the "real world." Actuator sort of implies physical motion, but you could also say that an LED that lights up when you want it to is an actuator of a sort...

Some actuators:

What's next?

In a minute we'll take a look at how some of these sensors and actuators work. But first we need to look at some basic ideas in electronics.

Part Two: super basic electronics