Input Devices

Question 1

Define Input Device

Answer 1

Peripherals used to provide data and control signals

Question 2

Define Barcode

Answer 2

• Represents data in machine readable form
• Check Digit for Validation
• Guard Bars = reference points for reader
• White reflects
• Photoelectric cells generate electrical pulses
• Processed and converted to binary number

Question 3

Define QR code

Answer 3

• Provide link
• Higher Storage Capacity
• Dedicated scanner or using camera

Question 4

Give examples of specialist devices for disabilities

Answer 4

• Sip/Puff Switch
• Foot Switches
• Braille Keyboard

Question 5

Define Digital Camera

Answer 5

• Open Shutter to allow light to enter the camera
• Lens focuses light on image sensor
• Array of photosites (intensity of light)
• Picture broken into pixels
• Bayar Filter RGB measures colour
• Demosaicing Algorithm determines value of each pixel (colour intensity of neighbours and itself)
• Image Processing Engine
• ADC
• Each pixel in numeric code

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Question 6

Define RFID

Answer 6

• Radio Frequency Identification
• Tag and Reader

Tag:

• Antenna
• Chip (process signals)
• Passive (no power)
• Active (battery, transmit at regular intervals) e.g. shops

Reader:

• Encoded Signal
• Can Process Multiple Tags