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Sensors and Data-logging
Many measuring devices (sensors)  can be linked to computers. This requires special software and usually a special interface.

Many sensors are digital - they produce one of a distinct set of values.

Other sensors are analogue - they can produce any value within a given range of numbers.

Analogue signals would need to be converted to digital signals by an analogue-to-digital converter (ADC), before the computer can process the readings.

 
Examples : Sensors can measure -
  • temperature eg to control a heating system
  • light eg to control automatic street lighting
  • sound eg to measure noise pollution
  • infra red eg photo cells may be used to detect a break in a beam in a burglar alarm system.
  • proximity eg to make sure robots do not crash into walls
  • pressure eg to make sure robotic 'hands' do not grip an object too tightly.
  • humidity eg to control an environment in a tropical greenhouse.

 

a sensor controlling  a light
Data-logging - a method of automatic data capture where a reading from a sensor is input at regular intervals. This data can then be processed to provide analysis of the environment.

The time interval between data readings needs to be set....as well as the total length of time for which readings are taken.

 
Exercise : Sensors
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