WASHING MAHINE

Washing machine is a best example for application specific embedded system and also typical example of an embedded system providing extensive support in home automation apllication 

An embedded system contains sensors,actuators,control unit and apllication specific user interfaces like keyboards,display units etc. We can see all these component in a washing machine if we have a close look at it. Some of them are visible anf some of them may be invisible to us.

ACTUATOR:

The actuator part of the washing machine consists of a motorized agitator, tumble tub, water drawing pump and inlet valve to control the flow of water into the unit

SENSOR:

The sensor part consist of the water temperature sensor, level sensor, etc.

CONTROL UNIT:

The control part contains a microprocessor/controller based board with interfaces to the sensor and actuators.

The sensor data  is fedback to the con- trol unit and control unit generates the necessary actuator outputs.

DISPLAY UNIT:

User feedback is reflected through the display unit and LEDs connected to the control board 

INTEGRATED CONTROL PANEL:

The integrated control panel consists of a microprocessor /conteoller based board with I/O interfaces and a control algorithm running in it.

INPUT INTERFACE:

Input interfaces includes the keyboard which consists of wash type selector namely wash, spin and rinse, cloth type selector namely , light,medium, heavy duty and washing time setting etc.

OUTPUT INTERFACE:

The output interface consists of LED/LCD displays,status indication LEDs,etc.Connected to the I/O bus of the controller .This interface may vaty from manufacture to manufacturer and model to model

The other types of I/O interfaces which are invisible to the user are different kinds of sensor interfaces, namely water temperature snesor, water etc.

Model of washinh machine 

Washing machine comes into two model, namely 

1. Top loadi g machines 
2. Front loading machines : In top loading model the agitator of the machine twists back and forth and pulls the cloths down to the bottom of the tub. On reaching the bottom of the tub the clothes work their way back up to the top of the tub where agitator grabs them again and repeats the machanidm
3. Spin phase: In the second phase of washing water is pumped out fron the tub and the inner tub uses centrifugal force to wring out more water from the clothes by spinning at several hundred rotations per minute (RPM). This id called a “spin phase”. Keyboard of washing machine contains three buttons namely wash, spin and rinse. We can use these buttons to configure the washing stqges.