3.2 Input devices

• a QR code scanner converts the squares into binary data
• optical mice use a laser to detect movement using a micro processor
• LCD (Liquid crystal display) is made up of millions of liquid crystals
• The LCD displays pixels arranged in a matrix
• advantage for LCD - low power consumption
• (LCD)advantage - they provide bright images and colours
• LED ( Light emitting diode) are tiny lights that make up large LED displays
• (LED) advantage - don't require backlighting which makes them thinner and lighter
• OLED (Organic light emitting diode) - use organic molecules to allow for more accurate colour definition
• Speakers - data is changed into electric current using a digital to analogue converter (DAC)
• DAC (digital analogue converter) - converts data into electrical current to create sound
• Infa-red sensors detect motion or a heat source e.g. a burglar
• ADC - analogue to digital, an electronic process that converts analogue data to digital for a computer to understand it.