[igCS] Analog and digital

[igCS] Analog and digital

Objectives

• Understand Analog and Digital Data

• ADC and DAC

• Microphone and speaker

• 
  

Analog Data

• Value is continuous

• Physical Data from the environment is analog

Digital

• Value is discrete (not continuous)

• Computers nowadays are digital

ADC (Analog to digital converter)

• Computer Processor cannot directly handle analog data

• But can only handle digital data

• ADC is to convert data from analog to digital

Multiple Choice

What is the black line representing?

• Analog Data

• Digital Data

• ADC

Multiple Choice

What is the pink line representing?

• Analog Data

• Digital Data

• ADC

How ADC works?

• Converting to digital means recording the value in discrete numbers

• We can "snapshot" the value in a regular interval and record as a series of value

• The technique is called "Sampling"

Microphone

• Microphone captures sound from environment (analog)

• an ADC converts the analog sound to computer digital format

• Sampling rate determines how frequent the data is recorded

Open Ended

The diagram on right shows higher sampling rate for a sound recording, while green line is the original sound in the environment. Explain how sampling rate affects the quality of sound.

DAC (Digital to Analog Converter)

• Computer can produce only digital output

• Output to physical world requires analog

• DAC is converting digital to analog output

DAC for speaker

• Computer music is digital

• A dedicated DAC chip is builtin to smartphone to convert digital music into audible sound waves (analog)

• The one on the picture is an external DAC to ensure higher quality of sound

Fill in the Blanks

When sound is capture by microphone, it is in

format?

Fill in the Blanks

Microprocessor / computer require

to read analog data

Fill in the Blanks

Computer cannot output to speaker directly because the data is in

format

Fill in the Blanks

The technique / process for converting from analog sound to digital computer data is called:

Well Done!

Fill in the Blanks

Computer cannot output to speaker directly because the data is in

format