Embedded System Introduction and microcontroller.ppt

Embedded System Introduction and microcontroller

1. 1
Embedded System Introduction
Mr. M. IDHAYACHANDRAN,
Assistant Professor of ECE,
Nadar Saraswathi College of Engineering and Technology,
Theni.

2. 2
EMBEEDED SYSTEMS
INTORDUCTION
COMPONENTS OF EMBEDDED SYSTEM
WORKING PRINCIPLE OF EMBEDDED SYSTEM
CHARACTERISTICS OF EMBEDDED SYSTEM
BASIC STRUCTURE OF EMBEDDED SYSTEM
TYPES OF EMBEDDED SYSTEM
APPLICATION OF EMBEDDED SYSTEM
ADVANTAGES OF EMBEDDED SYSTEM
DISADVANTAGES OF EMBEDDED SYSTEM

3. 3
According to the Institution of Electrical
Engineers, "A general purpose definition of
embedded systems is that they are devices used
to control, monitor or assist the operation of
equipment, machinery, or plant.
 'Embedded' reflects the fact that they are an
integral part of the system..." An embedded
system is a special-purpose computer system,
which is completely encapsulated by the device it
controls.
 An embedded system has specific
requirements and performs pre-defined tasks,
unlike a general-purpose personal computer.
What is an embedded system?

4. 4
Microcontrollers and Embedded System
Embedded Systems are a combination of Hardware
(microcontrollers) and Software (developed in
assembler, c, c++…) designed to perform a specific
function
An embedded product uses microcontrollers to do
one task and one task only.

5. FEATURES
Single-functioned
Tight design constrains
Reactive and Real-time operation
Memory management
Low manufacturing cost
Compact size and modular design
Ease of connectivity
Built-in safety measures
Long life cycle
5

6. 6
What is a Microcontroller?
A microcontroller (often abbreviated MCU) is a single computer chip
(integrated circuit) that executes a user program, normally for the
purpose of controlling some device, hence the name
microcontroller.
The program is normally contained either in a second chip, called
an EPROM, or within the same chip as the microcontroller itself.
A microcontroller is normally found in devices such as microwave
ovens, automobiles, keyboards, CD players, cell phones, VCRs,
security systems, time & attendance clocks, etc.

7. COMPONENTS OF
EMBEDDED SYSTEM
Hardware
Based around microprocessor and
microcontrollers
Software/Firmware
Real Time Operating Systems (RTOS)
That supervises the application software
and provide mechanism to let the
processor as per schedule by following a
plan to control the latencies.
7

8. Working Principle
Low cost, Low power consuming devices
that are embedded in other mechanical and
electrical systems.
Typically designed to deal with real-time
computing constraints and are controlled by
RTOS that can process data as it is
received without any buffer delay/queue
delay
8

9. Working Principle
Processor
Power supply
Memory
Communication protocol
Embedded system software and RTOS
Steps in the operation
Input reception
Processing
Action formation
9

10. Block Diagram
10

11. Characteristics of Embedded
System
Real-time operation
Task-specific
Tight design constraints
Connected peripherals
Low manufacturing cost
High reliability
Minimal user interface
11

12. 12

13. Basic structure of embedded
system
Sensors
ADC
Processors & ASIC
DAC
Actuators
13

14. Basic structure
14

15. Types of Embedded system
Based on performance and functional
requirements
Real-time embedded systems
Heart rate monitors, missile guidance system
Stand-alone embedded system
Washing machine, microwave ovens
Networked embedded system
Home security systems, smart thermostats
Mobile embedded system
Digital cameras, MP3 player
15

16. Based on performance of microcontroller
Small scale embedded system
8-bit, 16 bit microcontroller
Larger computer and dedicated to specific tasks
Simple sensors, LED controllers
Medium scale embedded system
16 bit, 32 bit microcontroller
Complex hardware and software integration
Advance home appliances, automotive control system
Sophisticated embedded system
Multiple 32 bit or 64 bit microcontroller
Industrial automation systems, advanced medical
devices, aerospace system
16

17. Types of embedded system
17

18. 18
Microprocessor Vs Microcontroller
Microcontrollers are used in devices that require some amount of
computing power but donot require as much computing power as that
provided by a complex (and expensive) 486, Pentium, i3 .. system
which generally requires a large amount of supporting circuitry (large
motherboards, hundreds of megabytes of RAM, hard drives, hard
drive controllers, video cards, etc).
A microwave oven just does not need that much computing power.
Microcontroller-based systems are generally smaller, more reliable,
and cheaper. They are ideal for the types of applications described
above where cost and unit size are very important considerations. In
such applications it is almost always desirable to produce circuits that
require the smallest number of integrated circuits, that require the
smallest amount of physical space, require the least amount of
energy, and cost as little as possible.

19. 19
Microcontroll
er
CPU
OSC
interrupt
Ext int
Address Bus (Uni dirctional)
Data Bus (Bi directional)
Control Lines

20. 20
Microcontroll
er
CPU
ROM RAM
Timer0
Timer1
OSC
interrupt
Ext int
Bus
control
4 I/o
ports
Serial
port

21. 21
FEATURE 8051 PENTIUM COMMENT
Clock Speed 12Mhz. typical
but 60MHz. ICs
available
1,000 MHz.
(1GHz.)
8051 internally divides
clock by 12 so for 12MHz.
clock effective clock rate is
just 1MHz.
Address bus 16 bits 32 bits 8051 can address 2
16
, or
64Kbytes of memory.
Pentium can address 2
32
, or
4 GigaBytes of memory.
Data bus 8 bits 64 bits Pentium’s wide bus allows
very fast data transfers.
ALU width 8 bits 32 bits But - Pentium has multiple
32 bit ALUs – along with
floating-point units.
ApplicationsDomestic
appliances,
Peripherals,
automotive etc.
Personal
Computers
And other high
performance areas.
Power
consumption
Small fraction of a
watt
Tens of watts Pentium runs hot as power
consumption increases
with frequency.
Cost of chipAbout RS.52/-About 6000/-
Simple comparison: Pentium vs. 8051

22. 22
Microcontroller Manufacturing Companies
There are FOUR major companies manufacturing
8 bit controllers
1.Motorola (6811)
2.Intel (8051 MCS51)
3. Zilog (Z8)
4.PIC (16X____) Microchip

23. 23
Port Organization of MCS51
Port 1
P1.0 – P1.7
Port 0
P0.0 – P0.7
Port 3
P3.0 – P3.7
Port 2
P2.0 – P2.7
P1
P0
P3 P2

24. 24
Port Assignments
Port 0 : Input/Output Port & AD0-AD7 for ext memory
Port 1 : Input/Output Port
Port 2 : Input/Output Port & A8-A15 for ext Memory
Port 3 : Input/Output Port
P3.0 : RxD
P3.1 : TxD
P3.2 : INTO’
P3.3 : INT1’
P3.4 : T0
P3.5 : T1
P3.6 : WR’
P3.7 : RD’

25. 25
Simple Experiment in
Embedded system

26. 26
89c51
9
+5V
GND
40
18
19
20
A Circuit using 89c51
Pin 40 +vcc
20 Gnd
9 Reset
18 OSC1
19 OSC2
31 Ext Access
31

27. 27
+ 5 volts
10 kOhms
b
f
e
d
c
a
g
a
b
f
e
d
c g
+ volts
I-RAM
7 6 5 4 3 2 1 0
S
F
R
s
Internal Memory
B0h
90h
P
O
R
T

3

(
P
3
)
P
O
R
T

1

(
P
1
)
P3.0
P3.1
P3.2
P3.3
P3.4
.5
.6
.7
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
Z
o
n
e

4
Z
o
n
e

3
Z
o
n
e

2
Z
o
n
e

1
8051 Chip
Burglar alarm system hardware

28. 28
S
w
itc
h
e
s
a
r
e
n
o
r
m
a
lly
c
lo
s
e
d
If any switch is opened
Input x goes high to indicate an
alarm condition
+ 5 volts
input x
b
e
d
c
a
f
g
a
e.g. 200 Ohm
Internal circuit within 7-segment
display device. (Common cathode
i.e. +5v input causes LED to light)
Input circuit
Output circuit

29. 29

Initialise I/O
ports P1 and P3
Read port P3
Are all
P3 inputs at 0
YES
NO
Sound alarm
Bell
ALARM_1 Program flow chart

30. 30
ORG 0000h ; define memory start address 000
; Initialise the I/O ports
MOV P3, #0ffh ; write all ones to P3 to use as an input port
MOV P1, #00 ; all zeros to put P1 in a known output state
POLL:
MOV A, P3 ; read P3 to accumulator
CJNE A, #00h, ALARM ; if not all zeros then jump to ALARM
LJMP POLL ; else loop back to POLL
ALARM:
SETB P1.7 ; enable the BELL by setting P1.7 high
END_LOOP:
LJMP END_LOOP ; program just loops around here
END ; end of program
ALARM_1 Program source code

31. 31
8051
P
o
r
t 1
P1.0
+ volts
Loudspeaker
Clock
12 MHz.
RESET
delay
1 ms.
delay
1 ms.
delay
1 ms.
delay
1 ms.
delay
1 ms.
SETB P1.0 SETB P1.0 SETB P1.0
CLR P1.0 CLR P1.0CLR P1.0
T = 2 msecs.
f = 1/T = 1 / 0.002
= 500 Hz.
P1.7
Hardware circuit with timing diagram for sound

32. 32
Interactive Vehicle Tracking System
It is a system which can track the vehicles for its movement
through out the trip with GPS And GPRS.
The data collected at different data points are stored at the vehicle
itself and in the computers of respective data points then to the
server.
The Data are
vehicle number, started time, stop time, Fuel at, Date, Fuel
type, Qty, Amount, Balance, Driver ID …..
The Data Points are
the places where the interactive RF transmitter and
receivers are fixed say BPCL fuel stations.

33. 33

At the data points
GPS & GPRS based RF transmitter and receivers (RF System) are
connected to a computers
GPS system is capable of interacting over area of 1 square metre
The GPS will transmit the data in
a periodic interval continuously
from the data point

34. 34
Block diagram of data locker
sensors
D i s p l a y
alarm
Micro
Controller
Memory
Start/stop
Load
Fuel
Transmitter
Receiver
GPS & GPRS
Server

35. 35
Block diagram of data point
Micro
Controller
Pump
Printer
Server
SMS
Pump link
circuit
Transmitter
Receiver
GPS & GPRS

36. 36
Advantages
• Compatible with any SMART cards
• Data is stored at data point (fuel station computer) and at the vehicle
•Vehicle owners can verify trip data from their office
• Data can be online with server
• Data can be on auto SMS from vehicle(GSM/CDMA/GPRS)
• Owners of the vehicles and dealers are not at the dark, but given with lot of
information about their vehicles for analysis
• 100% automated system

37. 37