Controller Systems

Tufts EMID - Spring 2015

Typical Controller System

Sensors

Acquisition System (Arduino)

Mapping Software (Max)

Output (Reason)

Useful Resources

Fraden, A Handbook of Modern Sensors

sensorwiki.org

Datasheets for components

Parts Sources

mouser.com

digikey.com

sparkfun.com

What can we sense?ON/OFF, momentary or toggle

Position, velocity, acceration, rotation

Temperature, light, sound

Pressure, touch, torque, bending, strain

Types of SensorsDiscrete - only can give a value of 0 (off) or 1 (on)

Continuous - Resistors or current generators. Some can be connected directly to the Arduino. Others need buffering, amplification, and/or filtering to provide usable data

Switches

Discrete output

Toggle - on or off

Momentary - on or off when pressed

Rotary: multiple-position

Can provide visual and tactile feedback

Potentiometers

Common types:

Linear taper

Audio taper (logarithmic)

Rotary, linear, multiturn

+Vref

Vout

GND

Soft Potentiometers

Linear

Circular

Other Variable Resistors

Photoresistors

Bend Sensors

Force-Sensing Resistors

Photoresistors/Photocells

Sense the absence or presence of light

Change resistance when amount of light changes

Bend SensorsResistance decreases when bent

Force-Sensitive Resistors

Resistance drops when pressed

Shorthand name: FSR

Variable Resistors

Vout = Vref R2/(R1+R2)

If sensor range = 10k to 35kΩ,

and R2 = 20kΩ then

Vout range = .66*Vref to .36*Vref

Vout

R2

R1 (variable)

+Vref

Accelerometers

Measure inclination (direction), acceleration in 1, 2, or 3 axes

Distance Sensors

Infrared

Ultrasonic

Piezoelectric Materials

Sensitive to vibration

Excellent drum triggers, contact microphones

Capacitive SensorsDetects changes in capacitance, often by measuring your body capacitance

Can detect proximity, distance, location, acceleration

Think: Trackpads, Cell/Tablet Screens, Theremin

Other Sensors

EMG (Muscle Sensor)

Joysticks (X and Y axis variable resistors)

Gesture Recognizers

Rotary Encoders

Connecting SensorsUsing Arduino boards

Read in digital and analog signals

Connect via USB and can talk to MAX

Breadboards

Simple way to create circuits without soldering

Reading in Data in MAX

Using Arduino2MAX

Putting It All Together

Arduino2MAX