Input and Output Devices

Input Devices

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

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

Uses of digital cameras

• Reading QR codes on a smartphone
• Video conferencing
• Robots, where information about surroundings is needed

Output Devices

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

Common output devices

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

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

Printers

Inkjet Printer Pros & Cons

• Produce high-quality photo/vivid colour images
• Do not 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 present 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