nothing

2. System :- A system is collection of element or
components that are organized for a comman
purpose.
A system also an arrangement in which all its units
assemble and work together according to the plan or
program.

3. Systems are mainly four types
Open and close system.
Abstract and physical system.
User machine system.
Deterministic and probabilistic system.
Eg: electric iorn, airconditioner items, Watch,
Washing machine ,etc.

4. Watch :
It is a time- display system.It parts are its haredware, needles
and battery with the beautiful dial, chasis and strap. These
parts organize to show real time every second and
continuously update the display using following some rules.
1. All needles move only clockwise.
2. A thin and long needle rotates every second.
3. A long needle rotates every minute.
4. A short needles rotates every hour such that it returns to
same position after twelve hours.
5. All needles return to the same inclination after twelve
hours each day .

5. Washing machine :
this system using as follows some rules.
1. Washing by spinning .
2. Rinse .
3. Drying.
4. Washing over by blinking.
5. Each step display the process stage.
6. In case interruption,execute only the
remaining.

6. Embedded system:
An embedded system is combination of
computer hardware and software,either fixed in
capability or programmable,designed for a specific
function or function within a larger system.

7. Component of embedded system

8. As we know embedded systems are the combination of
hardware and software. There are different component as
follows.
1. Power supply :
The power supply is an essential part of any
embedded system circuits. An embedded system may need
a supply of maximum 5volts or if it is low power then may
be 3.3volt or 1.8 volt. The supply may be provided with the
help of battery or we can use any wall adapter. It will
depend on the application need.

9. 2. Processor :
A processor is the main brain inside any
embedded systems. This is major factor affect the
performance of the system.
There are different processors available in
market. An embedded system may use microprocessor
or microcontroller.
The processor in different like 8-bit,16-bit,32-bit
and 64-bit architecture memory used. But 8-bit
processor is mostly used in small application where we
need some basic computation like input and output no
heavy processing.

10. 3. Memory:-
The microcontroller use mostly following three type
of memory.
•RAM :- Ram memory is volatile memory and used for
temporary storage of the data And the selection of it
depends on the user need and the application.
•ROM :-ROM memory or code memory is also called as
non-volatile memory. This is used for the storage of the
program. Once system powered, the system fetches the
code from the ROM memory.

11. •EEPROM :- It is a unique memory. The content can be
erasted and reprogrammed by a high voltage inputs.This
is used to store the data by the program it self.

12. 4. Timers and Counters :
In some application we need to generate some delay,
like for blinking an LED.
But there is some issues when we generate the delay
from the normal coding style by making any loop running
for a particular time, So it is not the best approach to
generate the delay for such kind of application where we
need a delay for a specific time interval without affecting
the normal code execution, we use timer and counter.

13. 5. Communication ports :
Embedded systems hardware has different
types of communication ports to communication with
the other embedded devices, like USB, Ethernet, RS-
232, RS-423, RS-485 and small level of
microcontroller communication port for example.
Popular Arduino UNO board has ATmega 328 IC and
following some ports loke UART, I2C,SPI, Front-end
processor based server, bus drivers etc.

14. 6. Input and Output :
Input may be provided by the user or by some
sensor. Sometimes some systems need more input or
output. So the processor selection will be based on
I/O.
These input and output are generally divided
into ports like p0,p1,p2&p3 in 8085 microcontrollers
and pA,pB ,pC &pD in ATmega series of
microcontroller.

15. 7. Application Specific Ciruits :
Some hardware components are common
while designing the embedded systems. But some
are different and depends on the application need.
Like a temperature sensor need a temperature sensor
for sensing the temperature.

16. Characteristics of embedded system:
1. Real time :-
Many embedded computing system have to perform in
real time ,if the data is not ready by certain deadline, the
system breaks.
Eg. A car’s brake system, if exceeds the time limit may cause
accidents.
2. Multirate :-
Not only must operations be completed by deadlines,
but many embedded computing systems have several real-time
activities going on at the same time.
Eg. the audio or video portions.
3. Power and energy:-
Power consumption directly affects the cost of the
hardware, since a larger power supply may be necessary.

17. 4. cost:-
The total cost of building the system is very
important in many cases. Manufacturing cost is
determined by many factors.
Embedded systems are built to achive certain
efficiency levels. They are small sized, can work with
less power and are not too expensive.
5. Minimal user interface :-
They have minimal or no longer user interface.
A fully automatic washing machine works on its own
after the programme is set and stops once the tasks is
over.

18. 6. Highly stability and reliability :-
Embedded sysyems can not be changed or
upgrade by the users.Hence,they must rank high on
reliability and stability. They are expected to function
for long durations without the user experiencing and
difficulties.
7 Complex algorithms:-
The operations performed by the
microprocessor may be very sophisticated. For
example, the microprocessor that controls an
automobile engine must perform complicated filtering
functions.

19. Advantages and Disadvantages of embedded system
Advantages :-
1. They are convenient for mass production. This results
in low price per piece.
2. These systems are highly stable and reliable.
3. Embedded Systems are made for specific tasks.
4. The embedded Systems are very small in size,hence can
be carried and loaded anywhere.
5. These systems are fast.They also use less power.
6.They improve the product quality.

20. Disadvantage:
1. Troubleshooting is difficult for embedded systems.
Transfering data from one system to another is also quite
problematic.
2. Because these systems are made for specific tasks,
hardware is limited.
•3. They are hard to maintain. It is also difficult to take a
back-up of embedded files.
4.Once configured, these systems cannot be charged . Hence,
no improvement or upgradation on the ones designed and
created can be made.

21. Application of embedded system:
1. Digital alarm clocks.
2. Electronic parking meters and parking pay stations.
3. Robotic vacuum cleaners (‘robovacs’).
4. Smart watches and digital wrist watches.
5. Washing machines and dishwashers.
6. Home security systems.
7. Air-conditioners and thermostats.
8. Electric stoves, pressure cookers, and tea/coffee
machines.
9. Traffic lights.