Microprocessors

Microprocessors are simple chips that have a dedicated function. they are found in a whole range of everyday items. These are computer control devices used in the home. Basically any device which can be programmed by data input, which is then processed, stored (remembered) and acted upon to provide some form of output. These are really self-contained microcomputers, called microcontrollers. They have input devices, output devices and processing chips all linked together and embedded inside them. You will not see the familiar keyboard and monitor but you will often find their equivalents in some form or other, otherwise you would not be able to give it your instructions (input) and see the results (output). The program used by the device is not loaded from disk like a normal computer but is permanently stored on an internal memory chip or ROM.

Automatic Washing Machine

Inputs devices: sensors for water flow, water level and temperature; door switch; selector knob or buttons for settings such as spin speed, temperature, load size and types of wash cycle required.

Processing: program to control all of the above settings.

Output devices: switches to operate the water pump, inlet and outlet valves, heater and drum motor.

Central Heating Controller

Inputs devices: buttons or keypad; temperature sensors for hot water storage tank, room air and radiators; timer switches; water flow sensor.

Processing: keeping time and on/off settings.

Output devices: switches to operate the water pump, valves, and boiler; LCD screen display.

Burglar or Car Alarm

Inputs devices: door and window switches; infra-red sensors; buttons or keypad for setting password and for activating and deactivating the system.

Processing: program to control all of the above settings and provide time to allow delayed activation of the system.

Output devices: buzzer; siren; bell; lights; telephone connection to security agency.

Video Cassette Recorder (VCR)

Inputs devices: control panel switches and infra-red detector for remote control; UHF channel sensor; sensor to read tape.

Processing: keep current time and date; respond to recording dates and times, scan and store channel settings; amplify and convert UHF signals.

Output devices: LCD display; tape drive motors; recording to tape device; video and sound output to television.

Microwave Oven

Inputs devices: door switch; buttons or keypad for settings such as time and heat output.

Processing: program to control all of the above settings.

Output devices: switches to operate the microwave generator, turntable motor, fan motor, interior light and warning bell; LCD screen display of inputs and current time.

Digital Watch

Inputs devices: button switches to set current time, alarm time and date.

Processing: program to keep an accurate calculation of the time and date and to control all of the above settings.

Output devices: LCD display or motor to move hands; beeper; back light.

Pocket Calculator

Inputs devices: button switches or keypad.

Processing: program to perform calculations.

Output devices: LCD display; button clicks.

Mobile Telephone

Inputs devices: button switches or keypad. NB this section refers to older style mobiles that cant be re-programmed.

Processing: program to perform connection to telephone network and to dial numbers; PIN number identification; store and process menu options.

Output devices: LCD display; button clicks; dialling and ringing tones; back light.

Toys

Inputs devices: sensors for sound and light; pressure or feeler switches; selector knob or buttons for settings or infra-red sensor for remote control device.

Processing: program to control all of the above settings.

Output devices: lights; sounds; motors; LED indicators; LCD screen.

© LEV