Electronics and Networks: Week 3: Dumb things with Wires (II) Sensors and Motors Jonah Brucker-Cohen Matthew Karau Monday 10am - 12pm Trinity College Dublin MSc. Multimedia Systems Spring 2003

Reading: Tyranny of the Moment Time = commodity Slow Time vs Fast Time = private periods where we are able to think without interruption are the most valuable Fighting for unavailability Past = finding information Present = filtering information More Technology = less time Any Thoughts?

Sensors and Motors Overview What are sensors and how can we use them? Examples of sensors (digital vs. analog) Sensors we have to play with Sensors in use What are motors and how can we use them? Examples of Motors Motor Controllers Motors in use In Class Lab

What are sensors and how can we use them? Sensors: Anything that receives a stimulus and can respond to it Example: Human - touch, taste, smell, see Machine - switch, pressure, light, heat, time, direction, force Sensors are used for controlling devices, reading input from the body, space, environment Connected to BS2 sensors can provide input to drive objects locally or through serial connections

Digital sensors return on/off values Switches: rocker switch, button, magnet switch, photo transistor, transistors, hall effects, pressure threshold, thermal, IR switch Examples of Sensors: Digital Others: Accelerometer, optical encoders

Analog Sensors return a gradual range of values Examples: Force Sensitive Resistors, Variable resitors: Potentiometers (pots), photo resistor, thermistor (heat), Sonar Examples of Sensors: Analog

Sensors we have to play with! Rocker Switches Potentiometers Hall Effects Accelerometers (coming soon) IR detectors/emmiters Sensors you come up with!

Sensors in Use Examples of Sensors used in projects Crank the web: magnets Copper Urchin: homemade switches Brain Ball: Brainwave Sensor Text Rain: camera

What are Motors and how can we use them? Motors are electrically charged magnets that pull or push on each other in one direction or another. The field magnet is stationary while the armature (with wire couled around it) or electromagnet is repelled or attracted by the field magnet. We can use motors for lots of things: cars, appliances,fans, clocks, massagers, mobile phones, CD Players, tape decks, car windows, toys, disk drives, aqauriums…

Examples of Motors DC motors: usually 3-5 vlts Used for simple, non-precise movement Ex. Fans, RC Cars, model trains High pin for BS2 Servo motors: hobby version 5 vlts Used for controllers - such as direction on RC toys, robotics for positioning Pulsout command for BS2 Stepper motors: Used for precise positioning - inkjet printers, digital plotters, steering, disk drives Motor controller needed

Motor Controllers Motor Controllers are separate pieces of hardware that interface to microcontrollers to control them - they all talk serial! A Few Examples: MotorMind B: allows you to control the polarity (backwards/forwards) Movement of a DC motor - Ex. If you wanted to make your own RC Car Little Step U - Used for controlling Stepper Motors For instance if you want to turn your desk Chair into a rotating clock Ferret FT639 : controls up to 5 Servo motors at once through serial If you wanted to make a robot walk - you can with one chip

Motors in use! Examples of cool projects that use lots o’ motors Robotlab: jukebots Snibbe: Breath Recorder Scratch Machine Danny Rozin: Wooden Mirror 500 Servo Motors turns wood into video

In Class Lab Play with stuff in class