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 Sensors Discrete - 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 +V ref V out 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 Sensors Resistance decreases when bent

Force-Sensitive Resistors Resistance drops when pressed Shorthand name: FSR

Variable Resistors V out = V ref R2/(R1+R2) If sensor range = 10k to 35kΩ, and R2 = 20kΩ then V out range =.66*V ref to.36*V ref V out R2 R1 (variable) +V ref

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 Sensors Detects 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 Sensors Using 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