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Electronics and Networks: Week 3: Dumb things with Wires (II)Sensors and Motors
Jonah Brucker-CohenMatthew KarauMonday 10am - 12pmTrinity College Dublin MSc. Multimedia SystemsSpring 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 Mirror500 Servo Motors turns wood into video
In Class LabPlay with stuff in class