Computing systems 2 (Sensors, Actuators, Transducers, Signals analogue, digital, ADCs, DACs, Systems approach)

generic steps for systems approach (3 words)

input → process → output

what is an input device

input device takes a real world signal (e.g. light, temperature), turns it into an electronic signal (e.g. current, voltage)

what is an output device

output devices turn an electronic signal into a real world signal (e.g. light, sound, movement)

example of input vs output devices:

input: LDR, thermistor, switches

output: LEDs, sound devices

define driver

a small program which tells an operating system how to respond to a particular hardware that is attached to the sustem

when is a driver needed

when a process device can’t provide a high enough signal for the output device to work correctly

drivers us transistors to amplify current or to control the direction of the movement of the motor

explain how a closed loop feedback system works, and example

the output signal of a central heating system has a direct effect on the input

e.g. central heating system:

output signal (temperature) is fed back into input, so that the system knows when to turn the heater off

what is a transducer

any device that converts between an electrical quantity and a real-world quantity.

what does a sensor do

known as what kind of transducer

input device which detects real-world quantities, then converted into an electrical signal

real world quantity, e.g. sound, light

input transducer

what does an actuator do

takes an electrical signal and converts it into a physical form

e.g. motor, speaker

output transducer

analogue signals cover all the ____ number of different voltage values

infinite

any digital systems needs signals from sensors to be translated to ____ signals before they can be processed

what does this

digital signals

ADCs

what does ADC stand for

analogue to digital converters

what do ADCs do/how does it work

devices which take samples of continuous analogue signals and encode the samples into discrete binary code

diagram, unofficial

if the ADC is located outside the sensor, the sensor is _____

analogue

if the sensor has the ADC built into it, it is a ______ sensor

digital

alternate definition for actuator

mechanical output devices that produce movement