3.2 INPUT and OUTPUT devices

What is an input device?

  • Hardware device used to provide data and control signals to a computer

What is an output device?

  • Hardware devices that allow information to be sent out of a computer system

Common input devices

  • Barcode Scanner
  • Digital Camera
  • Microphone
  • Optical Mouse
  • QR Scanner

Advantages of using QR Codes in a Supermarket

  • No need to price each item individually
  • automatic stock control
  • Faster checkouts as items are immediately scanned
  • Fewer errors in bills

Common output devices

  • Actuators
  • Inkjet,laser, 3D printer
  • LED,LCD screen
  • Speaker

Uses of digital cameras

  • reading QR codes on a smartphone
  • video conferencing
  • robots, where information about surroundings is needed

DLP Advantages

  • higher contrast ratios
  • greater longevity
  • quieter running

DLP Disadvantages

  • The image tends to suffer from ‘shadowing’ during moving images
  • They do not have grey components in the image
  • Colour definition is not as good as LCD projectors

Inkjet Printer Pros & Cons

  • produce high-quality photo/vivid colour images
  • don’t need to warm up
  • very low purchase price compared to laser printers
  • have a small ink reservoir
  • not suitable for long print runs (ink cartridges can be used up quickly)
  • small paper trays
  • Slower prints per minute compared to laser

Laser Printer Pros & Cons

  • have large paper trays for long print runs
  • have large capacity toner cartridges
  • very quiet printing
  • cost per page is very low
  • expensive to maintain (toner is expensive)
  • not suitable for printing high quality pictures
  • High up front cost (compared to inkjet)

Uses of a 3D Printer

  • Prosthetic Limbs
  • making prototypes
  • fashion and art

Which printer?

  • Laser printer: high volume printouts
  • Inkjet printer: High Quality image printouts
  • 3D printer: printing models/prosthetics

Sensors

  • Acoustic- measures the level of sound in an environment
  • Accelerometer-measures the acceleration forces
  • Flow-measures the amount of liquid or gas flowing through or around an environment
  • Gas- measures the presence and concentration of a gas in the atmosphere
  • Humidity-measures the level of moisture in the atmosphere
  • Infra-red-measures infra-red radiation
  • Level-measures whether a substance such as a liquid is at a certain level or amount
  • Light-measures the ambient light in a certain environment
  • Magnetic field-measures the presence of magnetic field that may be emitted by an object
  • Moisture-measures the amount of water that is presence in a substance
  • pH- measures the pH level of a substance
  • Pressure- measures the force of pressure that is applied to the sensor or device
  • Proximity- measures how close an object is in comparison to the sensor
  • Temperature-measures the temperature of an object or substance