MOBILE CONTROLLED IRRIGATION SYSTEM
A Project Report Submittedin Partial Fulfillment of the
Requirementsfor the Degree of
BACHELOR OF TECHNOLOGY
in
ELECTRONICS & COMMUNICATION ENGINEERING
by MAYANK JAIN VIKRAMADITYA SINGH VARUN KUMAR (2008UEC057)
(2008UEC104) (2008UEC102)
MAYUR MATHUR Under the Supervision of SONAL BHARDWAJ
(2008UEC059) (2007UEC )HEMANT KUM
to the
DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGG.INSTITUTE OF
ENGINEERING & TECHNOLOGYMANGALAYATAN UNIVERSITY ALIGARH
MANGALAYATAN UNIVERSITYBESWAN, ALIGARH
Department of Electronics and Communication Engineering
CERTIFICATE
This is to certify that the project work entitled MOBILE
CONTROLLED IRRIGATION SYSTEMis a bonafide work carried out by
MAYUR MATHUR (2008UEC059)VIKRAMADITYA SINGH(2008UEC104)VARUN
KUMAR(2008UEC102)MAYANK JAIN(2008UEC057)SONAL BHARDWAJ(2007UEC )in
partial fulfillment of the requirements for the degree of BACHELOR
OF TECHNOLOGY in ELECTRONICS & COMMUNICATION ENGINEERING by the
MANGALAYATAN UNIVERSITY during the academic year 2008-12.The
results embodied in this report have not been submitted to any
other University or Institution for the award of any degree or
diploma.
(Signature) (Signature) Mrs. HEMANT KUMAR Mr. SUDHIR MISHRA
LECTURER(ADVISOR FACULTY) HOD of ECE ACKNOWLEDGEMENT
We are highly indebted to our Faculty Liaison Mrs. Hemant Kumar
, Electronics and Communication Engineering Department, who has
given us all the necessary technical guidance in carrying out this
Project.
We wish to express our sincere thanks to Mr. Sudhir Mishra, Head
of the Department of Electronics and Communication Engineering,
Mangalayatan University, for permitting us to pursue our Project
and encouraging us throughout the Project.
Finally, we thank all the people who have directly or indirectly
help us through the course of our Project.
Mayank Jain (2008uec057)Mayur Mathur (2008uec059)Varun Kumar
(2008uec102)Vikramaditya Singh (2008uec104)Sonal Bhardwaj (2007uec
)ABSTRACT
Now a day's every system is automated in order to face new
challenges in the present day situation. Mobile controlled
irrigation systems have less manual operations, so that the
flexibility, reliabilities are high and accurate.
Probably the most useful thing to know about the global system
for mobile communication is that it is an international standard.
If you travel in parts of country, GSM is only type of cellular
service available. Instead of analog services, GSM was developed as
a digital system using TDMA technology.
The goal of the project is to develop a system, which uses
Mobile technology that keeps control of the irrigation system in
the field, which executes with respect to the signal sent by the
mobile.
The new concept has been thought to manage the irrigation system
remotely by using GSM, which enables the user to remotely control
switching of motor. Just by messaging through the mobile, from any
part of the country we can perform ON / OFF operation of the
motor.
TABLE OF CONTENTS
CERTIFICATE FROM ECE DEPARTMENT 3ACKNOWLEDGEMENTS 4ABSTRACT
5LIST OF FIGURES 6LIST OF TABLES 7
CHAPTER 1. INTRODUCTION
1.1 Aim of the project 111.2 Methodology 111.3 Organization of
work 12
CHAPTER 2. OVERVIEW
2.1 Overview of project 14 2.1.1 Block Diagram14 2.1.2 Circuit
Diagram 15 2.1.3 Description 16
CHAPTER3. HARDWARE DESCRIPTION
3.1 Microcontroller 19 3.1.1 A Brief History of 8051 19 3.1.2
Description of 89S52 Microcontroller 20 3.1.3 Block Diagram of
Microcontroller 22 3.1.4 Pin Configurations 23 3.1.5 Timers 30
3.1.6 Interrupts 33 3.1.7 Special function registers 36 3.1.8
Memory Organization 413.2 Power Supply 42 3.2.1 Regulator 3.2.2
Bridge rectifier 3.2.3 Transformer 3.2.4 Capacitor 3.2.5 Crystal
oscillator 3.2.6 Resistance 3.2.7 LED 3.2.8 LCD
3.3 Introduction To GSM CHAPTER 4. SOFTWARE DESCRIPTION 4
Introduction
CHAPTER 5. CONCLUSIONS
5.1 Conclusions and Future scope
BIBLOGRAPHY
REFERENCES
CHAPTER 1INTRODUCTION
1. INTRODUCTION 1.1 INTRODUCTIONThe aim of the project is to
develop a system, which uses mobile technology that keeps control
on irrigation system.Mobile Controlled irrigation system is
automatic control system which is capable of receiving a set of
command instructions in the form of Short message service and
performs the necessary actions like Start, Stop. We will be using a
dedicated modem at the receiver module i.e. with the robot itself
and send the commands using SMS service as per the required
actions. The mobile unit which is dedicated at the motor driver is
interfaced with an intellectual device called Micro controller so
that it takes the responsibility of reading the received commands
in the form of SMS from the mobile unit and perform the
corresponding predefined tasks such as motor start, stop, motor
direction and speed control at different levels etc.
In this project we interfaced 8051 Microcontroller with GSM
modem to decode the received message and do the required action.
The protocol used for the communication between the two is AT
command. The microcontroller continuously checks for SMS to take
the decision for controlling the motor.
This system can be used in fields for providing them with water
by switching on and offthe pumps at the field using a mobilephone.
For this purpose a GSM MODEM with a SIM card is to be attached to
the system and placed at the farmitself. User can send aparticular
format SMS to the system to turn ON and OFF thePump or Valve and
also set the ON and OFF time of Pump or Valve.
1.2 SIGNIFICANCE AND APPLICATIONS MOBILE CONTROLLED IRRIGATION
SYSTEM plays an important role in irrigation system. The ease of
the kit and low cost adds up an additional advantage for its usage.
Its significance can be proved by considering the following
specialties of kit designed by us RELAIBILITY: Relaibility is one
such factor that every electrical system should have in order to
render its services without malfunctioning over long period of
time. We have designed our kit using AT89s52 microcontroller which
is itself very reliable and also operates very efficiently under
normal conditions. COST: The design is implemented at a very
economical price. The total cost incurred by us in designing this
kit is very less and further we have developed the GSM which are
more economical rather than just interfacing those which are radily
available in market. The new concept has been thought to manage
them by mobile by using GSM, which enables user to remotely control
the motor. Just by dialing keypad of remote telephone, you can
on/off the motor by just sending the message.
1.3 ORGANISING OF THE REPORT The report totally consist of five
chapters Chapter 1 gives the introduction. Chapter 2 gives the
overview of the project. Chapter 3 gives the description of
hardware used. Chapter 4 gives the description of Software used.
Chapter 5 gives the conclusion.
CHAPTER 2OVERVIEW
2 OVERVIEW OF PROJECT 2.1.1 BLOCK DIAGRAM
8051LevelConverterSMS
GSM BASEDMotor Control
Motor
Fig.2.1-Block Diagram of Mobile Controlled Irrigation System
2.1.2 CIRCUIT DIAGRAM \
Fig 2.2 Circuit diagram of Mobile controlled irrigation
system
2.1.3 DESCRIPTION In this project we are going to control the
motor based on mobile communication. The idea behind this
particular work is to give user the full flexibility to control the
motor from remote distances when there is busy schedule concerned
to his daily routine. The main parts of this schematic diagram are:
1. TRANSFORMER. 2. BRIDGE RECTIFIER.3. MICROCONTROLLER UNIT
(AT89S52).4. GSM MODEM.5. REGULATOR.6. CRYSTAL OSCILLATOR.7. LIQUID
CRYSTAL DISPLAY.8. RESISTANCE.9. CAPACITOR.10. LIGHT EMITTING
DIODE.11. L293DNE IC.
The process to operate this project is first make a mobile to
mobile connection wirelessly or with a single mobile onboard wired.
But here we are using to mobiles to make is a wireless application.
Start with making a connection with the onboard mobile from remote
distance, then when connection is established lets control the
project with the data as follows:To operate the MOTOR just press 3
to switch ON and to switch OFF again press 6. This ON/OFF condition
of MOTOR is through GSM modem where switching is very fast and
accurate.
CHAPTER 3HARDWARE DESCRIPTION
3. HARDWARE DESCRIPTION
The block diagram of the system is as shown in the fig. The
system basically consists of a 1. Micro controller.2. Power supply.
3. GSM MODEM.
3.1 MICROCONTROLLER ARCHITECHTURE
3.1.1 A Brief History of 8051
In 1981, Intel Corporation introduced an 8 bit microcontroller
called 8051. This microcontroller had 128 bytes of RAM, 4K bytes of
chip ROM, two timers, one serial port, and four ports all on a
single chip. At the time it was also referred as A SYSTEM ON A
CHIPThe 8051 is an 8-bit processor meaning that the CPU can work
only on 8 bits data at a time. Data larger than 8 bits has to be
broken into 8 bits pieces to be processed by the CPU. The 8051 has
a total of four I\O ports each 8 bit wide.There are many versions
of 8051 with different speeds and amount of on-chip ROM and they
are all compatible with the original 8051. This means that if you
write a program for one it will run on any of them.The 8052 is an
original member of the 8051 family. There are two other members in
the 8051 family of microcontrollers. They are 8052 and 8031. All
the three microcontrollers will have the same internal
architecture, but they differ in the following aspects. 1. 8031 has
128 bytes of RAM, two timers and 6 interrupts. 2. 89S51 has 4KB
ROM, 128 bytes of RAM, two timers and 6 interrupts.3. 89S52 has 8KB
ROM, 128 bytes of RAM, three timers and 8 interrupts.Of the three
microcontrollers, 89S51 is the most preferable. Microcontroller
supports both serial and parallel communication.In the concerned
project 89S52 microcontroller is used. Here microcontroller used is
AT89S52, which is manufactured by ATMEL laboratories.
3.1.2 Description of 89S52 Microcontroller
The AT89S52 provides the following standard features: 8Kbytes of
Flash, 256 bytes of RAM, 32 I/O lines, three 16-bit timer/counters,
six-vector two-level interrupt architecture, a full duplex serial
port, on-chip oscillator, and clock circuitry. In addition, the
AT89S52 is designed with static logic for operation down to zero
frequency and supports two software selectable power saving modes.
The Idle Mode stops the CPU while allowing the RAM, timer/counters,
serial port, and interrupt system to continue functioning. The
Power down Mode saves the RAM contents but freezes the oscillator,
disabling all other chip functions until the next hardware
reset.
By combining a versatile 8-bit CPU with Flash on a monolithic
chip, the AT89S52 is a powerful microcomputer which provides a
highly flexible and cost effective solution to many embedded
control applications.
Features of Microcontroller (89S52)
1. Compatible with MCS-51 Products2. 8 Kbytes of In-System
Reprogrammable Flash Memory3. Endurance: 1,000 Write/Erase Cycles4.
Fully Static Operation: 0 Hz to 24 MHz5. Three-Level Program Memory
Lock6. 256 x 8-Bit Internal RAM7. 32 Programmable I/O Lines8. Three
16-Bit Timer/Counters9. Eight vector two level Interrupt Sources10.
Programmable Serial Channel11. Low Power Idle and Power Down
Modes12. In addition, the AT89S52 is designed with static logic for
operation down to zero frequency and supports two software
selectable power saving modes.
The Idle Mode stops the CPU while allowing the RAM,
timer/counters, serial port and interrupt system to continue
functioning. The Power down Mode saves the RAM contents but freezes
the oscillator disabling all other chip functions until the next
hardware reset.
3.1.3 Block Diagram of Microcontroller
Fig 3.1:Functional block diagram of AT89S52
3.1.4 Pin Configuration
Fig.3.2-Pin Diagram of Microcontroller
Pin Description
VCCPin 40 provides Supply voltage to the chip. The voltage
source is +5v.
GND.Pin 20 is the grounded.
Port 0Port 0 is an 8-bit open drain bidirectional I/O port from
pin 32 to 39. As an output port each pin can sink eight TTL inputs.
When 1s are written to port 0 pins, the pins can be used as
high-impedance inputs. Port 0 may also be configured to be the
multiplexed low-order address/data bus during accesses to external
program and data memory. In this mode P0 has internal pull-ups.
Port 0 also receives the code bytes during Flash programming, and
outputs the code bytes during program verification. External
pull-ups are required during program verification.
Port 1Port 1 is an 8-bit bidirectional I/O port with internal
pull-ups from pin 1 to 8. The Port 1 output buffers can sink/source
four TTL inputs. When 1s are written to Port 1 pins they are pulled
high by the internal pull-ups and can be used as inputs. As inputs,
Port 1 pins that are externally being pulled low will source
current (IIL) because of the internal pull-ups. In addition, P1.0
and P1.1 can be configured to be the timer/counter 2 external count
input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX),
respectively, as shown in following table. Port 1 also receives the
low-order address bytes during Flash programming and program
verification.
Port 2Port 2 is an 8-bit bidirectional I/O port with internal
pull-ups from pin 21 to 28. The Port 2 output buffers can sink /
source four TTL inputs. When 1s are written to Port 2 pins they are
pulled high by the internal pull-ups and can be used as inputs. As
inputs, Port 2 pins that are externally being pulled low will
source current (IIL) because of the internal pull-ups.Port 2 emits
the high-order address byte during fetches from external program
memory and during accesses to external data memory that uses 16-bit
addresses (MOVX @ DPTR). In this application it uses strong
internal pull-ups when emitting 1s. During accesses to external
data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the
contents of the P2 Special Function Register. Port 2 also receives
the high-order address bits and some control signals during Flash
programming and verification.
Port 3Port 3 is an 8-bit bidirectional I/O port with internal
pull-ups from pin 10 to 17. The Port 3 output buffers can sink /
source four TTL inputs. When 1s are written to Port 3 pins they are
pulled high by the internal pull-ups and can be used as inputs. As
inputs, Port 3 pins that are externally being pulled low will
source current (IIL) because of the pull-ups. Port 3 also serves
the functions of various special features of the AT89C52 as listed
below
Table 3.1 Special Features of port3
Port 3 also receives some control signals for Flash programming
and programming verification.
RSTPin 9 is the Reset input. It is active high. Upon applying a
high pulse to this pin, the microcontroller will reset and
terminate all activities. A high on this pin for two machine cycles
while the oscillator is running resets the device.
ALE/PROGAddress Latch is an output pin and is active high.
Address Latch Enable output pulse for latching the low byte of the
address during accesses to external memory. This pin is also the
program pulse input (PROG) during Flash programming. In normal
operation ALE is emitted at a constant rate of 1/6 the oscillator
frequency, and may be used for external timing or clocking
purposes. Note, however, that one ALE pulse is skipped during each
access to external Data Memory. If desired, ALE operation can be
disabled by setting bit 0 of SFR location 8EH. With the bit set,
ALE is active only during a MOVX or MOVC instruction. Otherwise,
the pin is weakly pulled high. Setting the ALE-disable bit has no
effect if the microcontroller is in external execution mode.
PSENProgram Store Enable is the read strobe to external program
memory. When the AT89S52 is executing code from external program
memory, PSEN is activated twice each machine cycle, except that two
PSEN activations are skipped during each access to external data
memory.
EA/VPPExternal Access Enable EA must be strapped to GND in order
to enable the device to fetch code from external program memory
locations starting at 0000H up to FFFFH. Note, however, that if
lock bit 1 is programmed, EA will be internally latched on reset.
EA should be strapped to VCC for internal program executions. This
pin also receives the 12-volt programming enable voltage (VPP)
during Flash programming when 12-volt programming is selected.
XTAL1Input to the inverting oscillator amplifier and input to
the internal clock operating circuit.
XTAL2Output from the inverting oscillator amplifier.
Oscillator CharacteristicsXTAL1 and XTAL2 are the input and
output, respectively, of an inverting amplifier which can be
configured for use as an on chip oscillator, as shown in Figure
5.3. Either a quartz crystal or ceramic resonator may be used. To
drive the device from an external clock source, XTAL2 should be
left unconnected while XTAL1 is driven .
Fig. 3.3 Crystal Connections
Fig. 3.4 External Clock Drive ConfigurationThere are no
requirements on the duty cycle of the external clock signal, since
the input to the internal clocking circuitry is through a divide-by
two flip-flop, but minimum and maximum voltage high and low time
specifications must be observed.
Idle ModeIn idle mode, the CPU puts itself to sleep while all
the on-chip peripherals remain active. The mode is invoked by
software. The content of the on-chip RAM and all the special
functions registers remain unchanged during this mode. The idle
mode can be terminated by any enabled interrupt or by a hardware
reset. It should be noted that when idle is terminated by a
hardware reset, the device normally resumes program execution, from
where it left off, up to two machine cycles before the internal
reset algorithm takes control. On-chip hardware inhibits access to
internal RAM in this event, but access to the port pins is not
inhibited. To eliminate the possibility of an unexpected write to a
port pin when Idle is terminated by reset, the instruction
following the one that invokes Idle should not be one that writes
to a port pin or to external memory.
Power down ModeIn the power down mode the oscillator is stopped,
and the instruction that invokes power down is the last instruction
executed. The on-chip RAM and Special Function Registers retain
their values until the power down mode is terminated. The only exit
from power down is a hardware reset. Reset redefines the SFRs but
does not change the on-chip RAM. The reset should not be activated
before VCC is restored to its normal operating level and must be
held active long enough to allow the oscillator to restart and
stabilize.
Table 3.2 Status Of External Pins During Idle and Power Down
Mode
Program Memory Lock BitsOn the chip are three lock bits which
can be left unprogrammed (U) or can be programmed (P) to obtain the
additional features listed in the table 5.4. When lock bit 1 is
programmed, the logic level at the EA pin is sampled and latched
during reset. If the device is powered up without a reset, the
latch initializes to a random value, and holds that value until
reset is activated. It is necessary that the latched value of EA be
in agreement with the current logic level at that pin in order for
the device to function properly.
Table 3.3 Lock Bit Protection Modes
TIMERS
Timer 0 and 1Timer 0 and Timer 1 in the AT89S52 operate the same
way as Timer 0 and Timer 1 in the AT89S52.Register pairs (TH0,
TL1), (TH1, TL1) are the 16-bit counter registers for timer/
counters 0 and 1. Timer 2Timer 2 is a 16-bit Timer/Counter that can
operate as either a timer or an event counter. The type of
operation is selected by bit C/T2 in the SFR T2CON. Timer 2 has
three operating modes: capture, auto-reload (up or down counting),
and baud rate generator. The modes are selected by bits in T2CON,
as shown in Table 5.2. Timer 2 consists of two 8-bit registers, TH2
and TL2. In the Timer function, the TL2 register is incremented
every machine cycle. Since a machine cycle consists of 12
oscillator periods, the count rate is 1/12 of the oscillator
frequency.
Table 3.4 Timer 2 Operating Modes
In the Counter function, the register is incremented in response
to a 1-to-0 transition at its corresponding external input pin, T2.
In this function, the external input is sampled during S5P2 of
every machine cycle. When the samples show a high in one cycle and
a low in the next cycle, the count is incremented. The new count
value appears in the register during S3P1 of the cycle following
the one in which the transition was detected. Since two machine
cycles (24 oscillator periods) are required to recognize a 1-to-0
transition, the maximum count rate is 1/24 of the oscillator
frequency. To ensure that a given level is sampled at least once
before it changes, the level should be held for at least one full
machine cycle.There are no restrictions on the duty cycle of
external input signal, but it should for at least one full machine
to ensure that a given level is sampled at least once before it
changes.
3.1.5 Interrupts
The AT89C52 has a total of six interrupt vectors: two external
interrupts (INT0 and INT1), three timer interrupts (Timers 0, 1,
and 2), and the serial port interrupt. These interrupts are all
shown in Figure 2.5
Fig. 3.5 Interrupts Source
Each of these interrupt sources can be individually enabled or
disabled by setting or clearing a bit in Special Function Register
IE. IE also contains a global disable bit, EA, which disables all
interrupts at once. Note that Table 5.3 shows that bit position
IE.6 is unimplemented. In the AT89C51, bit position IE.5 is also
unimplemented. User software should not write 1s to these bit
positions, since they may be used in future AT89 products.
Table 3.5 Interrupts Enable Register
Timer 2 interrupt is generated by the logical OR of bits TF2 and
EXF2 in register T2CON. Neither of these flags is cleared by
hardware when the service routine is vectored to. In fact, the
service routine may have to determine whether it was TF2 or EXF2
that generated the interrupt, and that bit will have to be cleared
in software.
The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of
the cycle in which the timers overflow. The values are then polled
by the circuitry in the next cycle. However, the Timer 2 flag, TF2,
is set at S2P2 and is polled in the same cycle in which the timer
overflows.
3.1.6 Special function registers:Special function registers are
the areas of memory that control specific functionality of the
89c52 microcontroller.
a) Accumulator (0E0h)As its name suggests, it is used to
accumulate the results of large no. of instructions. It can hold 8
bit values.
b) B register (oFoh)The B register is very similar to
accumulator. It may hold 8-bit value. The B register is only used
by MUL AB and DIV AB instructions. In MUL AB the higher byte of the
products gets stored in B register. In DIV AB the quotient gets
stored in B with the remainder in A.
c) Stack pointer (081h)The stack pointer holds 8-bit value. This
is used to indicate where the next value to be removed from the
stack should be taken from. When a value is to be pushed on to the
stack, the 8052 first store the value of SP and then store the
value at the resulting memory location. When a value is to be
popped from the stack, the 8052 returns the value from the memory
location indicated by SP and then decrements the value of SP.
d) Data pointer (Data pointer low/high, address 82/83h)The SFRs
DPL and DPH work together to represent a 16-bit value called the
data pointer. The data pointer is used in operations regarding
external RAM and some instructions code memory. It is a 16-bit SFR
and also an addressable SFR.
e) Program counter The program counter is a 16 bit register,
which contains the 2 byte address, which tells the next instruction
to execute to be found in memory. When the 8052 is initialized PC
starts at 0000h and is incremented each time an instruction is
executes. It is not addressable SFR.
f) PCON (power control, 87h)The power control SFR is used to
control the 8052s power control modes. Certain operation modes of
the 8052 allow the 8052 to go into a type of sleep mode which
consumes low power.SMOD ----------- GF1 GF0 PDIDL
g)TCON(Timer control, 88h)The timer mode control SFR is used to
configure and modify the way in which the 8052s two timers operate.
This SFR controls whether each of the two timers is running or
stopped and contains a flag to indicate that each timer has
overflowed. Additionally, some non-timer related bits are located
in TCON SER. These bits are used to configure the way in which the
external interrupt flags are activated, which are set when an
external interrupt occur.TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0
h)TMOD(Timer Mode,89h)The timer mode SFR is used to configure
the mode of operation of each of the two timers. Using this SR your
program may configure each timer to be a 16-bit timer, or 13 bit
timer, 8-bit auto reload timer, or two separate timers.
Additionally you may configure the timers to only count when an
external pin is activated or to count events that are indicated on
an external pin.
GateC/ T M1 M0Gate C/ TM1M0
TIMER1 TIMER0
i) T0 (Timer 0 low/ high, address 8A/ 8C h) These two SFRs
together represent timer 0. Their exact behavior depends on how the
timer is configured in the TMOD SFR; however, these timers always
count up. What is configurable is how and when they increment
value.
j) T1 (Timer 1 low/ high, address 8B/ 8D h) These two SFRs
together represent timer 1. Their exact behavior depends on how the
timer is configured in the TMOD SFR; however, these timers always
count up. What is configurable is how and when they increment in
value.
k) P0 (Port 0, address 80h, bit addressable)This is port 0
latch. Each bit of this SFR corresponds to one of the pins on a
micro controller. Any data to be outputted to port 0 is first
written on P0 register. For e.g., bit 0 of port 0 is pin P0.0, bit
7 is pin P0.7. Writing a value of 1 to a bit of this SFR will send
a high level on the corresponding I/O pin whereas a value of 0 will
bring it to low level. l) P1(Port 1, address 90h, bit
addressable)This is port 1 latch. Each bit of this SFR corresponds
to one of the pins on a micro controller. Any data to be outputted
to port 1 is first written on P1 register. For e.g., bit 0 of port
1 is pin P1.0, bit 7 is pin P1.7. Writing a value of 1 to a bit of
this SFR will send a high level on the corresponding I/O pin
whereas a value of 0 will bring it to low level.
m) P2 (Port 2, address 0A0h, bit addressable)This is port 2
latch. Each bit of this SFR corresponds to one of the pins on a
micro controller. Any data to be outputted to port 2 is first
written on P2 register. For e.g., bit 0 of port 2 is pin P2.0, bit
7 is pin P2.7. Writing a value of 1 to a bit of this SFR will send
a high level on the corresponding I/O pin whereas a value of 0 will
bring it to low level.
n) P3 (Port 3, address 0B0h, bit addressable)This is port 3
latch. Each bit of this SFR corresponds to one of the pins on a
micro controller. Any data to be outputted to port 3 is first
written on P3 register. For e.g., bit 0 of port 3 is pin P3.0, bit
7 is pin P3.7. Writing a value of 1 to a bit of this SFR will send
a high level on the corresponding I/O pin whereas a value of 0 will
bring it to low level.
o) IE (Interrupt Enable, 0A8h)The interrupt enable SFR is used
to enable and disable specific interrupts. The low 7 bits of the
SFR are used to enable/disable the specific interrupts, where the
MSB bit is used to enable or disable all the interrupts. Thus, if
the high bit of IE 0 all interrupts are disabled regardless of
whether an individual interrupt is enabled by setting a lower
bit.
EA _ _ _ ET2 ES ET1 EX1 ET0 EX0
p) IP (Interrupt Priority, 0B8h)The interrupt priority SFR is
used to specify the relative priority of each interrupt. On 8052,
an interrupt may be either low or high priority. An interrupt may
interrupt interrupts. For e.g., if we configure all interrupts as
low priority other than serial interrupt. The serial interrupt
always interrupts the system; even if another interrupt is
currently executing no other interrupt will be able to interrupt
the serial interrupt routine since the serial interrupt routine has
the highest priority.
_ _ __ _ _ PT2 PS PT1 PX1 PT0 PX0
q)PSW (Program Status Word, 0D0h)The Program Status Word is used
to store a number of important bits that are set and cleared by
8052 instructions. The PSW SFR contains the carry flag, the
auxiliary carry flag, the parity flag and the overflow flag.
Additionally, it also contains the register bank select flags,
which are used to select, which of the R register banks currently
in use. CY AC F0 RS1 RS0 OV- - - - P
r) SBUF (Serial Buffer, 99h)SBUF is used to hold data in serial
communication. It is physically two registers. One is writing only
and is used to hold data to be transmitted out of 8052 via TXD. The
other is read only and holds received data from external sources
via RXD. Both mutually exclusive registers use address 99h.
3.2. POWER SUPPLY
CIRCUIT DIAGRAM OF POWER SUPPLY
Fig.3.6-Circuit Diagram of Power Supply
3.2.1 REGULATOR A variable regulated power supply, also called a
variable bench power supply, is one where you can continuously
adjust the output voltage to your requirements. Varying the output
of the power supply is the recommended way to test a project after
having double checked parts placement against circuit drawings and
the parts placement guide. This type of regulation is ideal for
having a simple variable bench power supply. Actually this is quite
important because one of the first projects a hobbyist should
undertake is the construction of a variable regulated power supply.
While a dedicated supply is quite handy e.g. 5V or 12V, it's much
handier to have a variable supply on hand, especially for testing.
Most digital logic circuits and processors need a 5 volt power
supply. To use these parts we need to build a regulated 5 volt
source. Usually you start with an unregulated power supply ranging
from 9 volts to 24 volts DC (A 12 volt power supply is included
with the Beginner Kit and the Microcontroller Beginner Kit.). To
make a 5 volt power supply, we use a LM7805 voltage regulator IC
.
Fig.3.7-Regulator
The LM7805 is simple to use. You simply connect the positive
lead of your unregulated DC power supply (anything from 9VDC to
24VDC) to the Input pin, connect the negative lead to the Common
pin and then when you turn on the power, you get a 5 volt supply
from the Output pin.
Circuit Features: Brief description of operation: Gives out well
regulated +5V output, output current capability of 100 mA Circuit
protection: Built-in overheating protection shuts down output when
regulator IC gets too hot Circuit complexity: Very simple and easy
to build Circuit performance: Very stable +5V output voltage,
reliable operation Availability of components: Easy to get, uses
only very common basic components Design testing: Based on
datasheet example circuit, I have used this circuit successfully as
part of many electronics projects Applications: Part of electronics
devices, small laboratory power supply Power supply voltage:
Unregulated DC 8-18V power supply Power supply current: Needed
output current + 5 mA Component costs: Few dollars for the
electronics components + the input transformer cost.
IC Voltage Regulators:
Voltage regulators comprise a class of widely used ICs.
Regulator IC units contain the circuitry for reference source,
comparator amplifier, control device, and overload protection all
in a single IC. Although the internal construction of the IC is
somewhat different from that described for discrete voltage
regulator circuits, the external operation is much the same. IC
units provide regulation of either a fixed positive voltage, a
fixed negative voltage, or an adjustably set voltage.A power supply
can be built using a transformer connected to the ac supply line to
step the ac voltage to desired amplitude, then rectifying that ac
voltage, filtering with a capacitor and RC filter, if desired, and
finally regulating the dc voltage using an IC regulator. The
regulators can be selected for operation with load currents from
hundreds of mill amperes to tens of amperes, corresponding to power
ratings from mill watts to tens of watts. Three-Terminal Voltage
Regulators: Fixed Positive Voltage Regulators:
IN OUT78XX GNDVin VoutC1 C2
Fig.3.8-Circuit Diagram of Voltage RegulatorFig shows the basic
connection of a three-terminal voltage regulator IC to a load. The
fixed voltage regulator has an unregulated dc input voltage, Vi,
applied to one input terminal, a regulated output dc voltage, Vo,
from a second terminal, with the third terminal connected to
ground. While the input voltage may vary over some permissible
voltage range, and the output load may vary over some acceptable
range, the output voltage remains constant within specified voltage
variation limits. A table of positive voltage regulated ICs is
provided in table. For a selected regulator, IC device
specifications list a voltage range over which the input voltage
can vary to maintain a regulated output voltage over a range of
load current. The specifications also list the amount of output
voltage change resulting from a change in load current (load
regulation) or in input voltage (line regulation).IC No.Output
voltage(v)Maximum input voltage(v)
78057806780878107812781578187824
+5+6+8+10+12+15+18+24
35V
40V
Table.3.6-Shows Regulator of series 78XX
3.2.2 BRIDGE RECTIFIER
A more widely used full-wave rectifier circuit is the bridge
rectifier. It requires four diodes instead of two, but avoids the
need for a centre-tapped transformer. During the positive
half-cycle of the secondary voltage, diodes D2 and D4 are
conducting and diodes D1 and D3 are non-conducting. Therefore,
current flows through the secondary winding, diode D2, load
resistor RL and diode D4. During negative half-cycles of the
secondary voltage, diodes D1 and D3 conduct, and the diodes D2 and
D4 do not conduct. The current therefore flows through the
secondary winding, diode D1, load resistor RL and diode D3. In both
cases, the current passes through the load resistor in the same
direction. Therefore, a fluctuating, unidirectional voltage is
developed across the load.
Filtration
The rectifier circuits we have discussed above deliver an output
voltage that always has the same polarity: but however, this output
is not suitable as DC power supply for solid-state circuits. This
is due to the pulsation or ripples of the output voltage. This
should be removed out before the output voltage can be supplied to
any circuit. This smoothing is done by incorporating filter
networks. The filter network consists of inductors and capacitors.
The inductors or choke coils are generally connected in series with
the rectifier output and the load. The inductors oppose any change
in the magnitude of a current flowing through them by storing up
energy in a magnetic field. An inductor offers very low resistance
for DC whereas; it offers very high resistance to AC. Thus, a
series connected choke coil in a rectifier circuit helps to reduce
the pulsations or ripples to a great extent in the output voltage.
The fitter capacitors are usually connected in parallel with the
rectifier output and the load. As, AC can pass through a capacitor
but DC cannot, the ripples are thus limited and the output becomes
smoothed. When the voltage across its plates tends to rise, it
stores up energy back into voltage and current. Thus, the
fluctuations in the output voltage are reduced considerable. Filter
network circuits may be of two types in general:
Choke Input Filters
If a choke coil or an inductor is used as the first- components
in the filter network, the filter is called choke input filter. The
D.C. along with AC pulsation from the rectifier circuit at first
passes through the choke (L). It opposes the AC pulsations but
allows the DC to pass through it freely. Thus AC pulsations are
largely reduced. The further ripples are by passed through the
parallel capacitor C. But, however, a little nipple remains
unaffected, which are considered negligible. This little ripple may
be reduced by incorporating a series a choke input filters.
CAPACITOR INPUT FILTERIf a capacitor is placed before the
inductors of a choke-input filter network, the filter is called
capacitor input filter. The D.C. along with AC ripples from the
rectifier circuit starts charging the capacitor C. to about peak
value. The AC ripples are then diminished slightly. Now the
capacitor C, discharges through the inductor or choke coil, which
opposes the AC ripples, except the DC. The second capacitor C by
passes the further AC ripples. A small ripple is still present in
the output of DC, which may be reduced by adding additional filter
network in series.
3.2.3 TRANSFORMER
A transformer is a device that transfers electrical energy from
one circuit to another through inductively coupled conductors the
transformer's coils or "windings". Except for air-core
transformers, the conductors are commonly wound around a single
iron-rich core, or around separate but magnetically-coupled cores.
A varying current in the first or "primary" winding creates a
varying magnetic field in the core (or cores) of the transformer.
This varying magnetic field induces a varying electromotive force
(EMF) or "voltage" in the "secondary" winding. This effect is
called mutual induction.
Fig.3.9-TransformerIf a load is connected to the secondary
circuit, electric charge will flow in the secondary winding of the
transformer and transfer energy from the primary circuit to the
load connected in the secondary circuit.The secondary induced
voltage VS, of an ideal transformer, is scaled from the primary VP
by a factor equal to the ratio of the number of turns of wire in
their respective windings:
BASIC PARTS OF A TRANSFORMER In its most basic form a
transformer consists of: A primary coil or winding. A secondary
coil or winding. A core that supports the coils or windings. Refer
to the transformer circuit in figure as you read the following
explanation: The primary winding is connected to a 60-hertz ac
voltage source. The magnetic field (flux) builds up (expands) and
collapses (contracts) about the primary winding. The expanding and
contracting magnetic field around the primary winding cuts the
secondary winding and induces an alternating voltage into the
winding. This voltage causes alternating current to flow through
the load. The voltage may be stepped up or down depending on the
design of the primary and secondary windings.
Fig.3.10- Diagram of Transformer
COMPONENTS OF A TRANSFORMER
Two coils of wire (called windings) are wound on some type of
core material. In some cases the coils of wire are wound on a
cylindrical or rectangular cardboard form. In effect, the core
material is air and the transformer is called an AIR-CORE
TRANSFORMER. Transformers used at low frequencies, such as 60 hertz
and 400 hertz, require a core of low-reluctance magnetic material,
usually iron. This type of transformer is called an IRON-CORE
TRANSFORMER. Most power transformers are of the iron-core type. The
principle parts of a transformer and their functions are:
The CORE, which provides a path for the magnetic lines of flux.
The PRIMARY WINDING, which receives energy from the ac source. The
SECONDARY WINDING, which receives energy from the primary winding
and delivers it to the load. The ENCLOSURE, which protects the
above components from dirt, moisture, and mechanical damage.
3.2.4 CAPACITORS
It is an electronic component whose function is to accumulate
charges and then release it.To understand the concept of
capacitance, consider a pair of metal plates which all are placed
near to each other without touching. If a battery is connected to
these plates the positive pole to one and the negative pole to the
other, electrons from the battery will be attracted from the plate
connected to the positive terminal of the battery. If the battery
is then disconnected, one plate will be left with an excess of
electrons, the other with a shortage, and a potential or voltage
difference will exists between them. These plates will be acting as
capacitors. Capacitors are of two types: - (1) fixed type like
ceramic, polyester, electrolytic capacitors-these names refer to
the material they are made of aluminium foil. (2) Variable type
like gang condenser in radio or trimmer. In fixed type capacitors,
it has two leads and its value is written over its body and
variable type has three leads. Unit of measurement of a capacitor
is farad denoted by the symbol F. It is a very big unit of
capacitance. Small unit capacitor are pico-farad denoted by pf
(Ipf=1/1000,000,000,000 f) Above all, in case of electrolytic
capacitors, it's two terminal are marked as (-) and (+) so check it
while using capacitors in the circuit in right direction. Mistake
can destroy the capacitor or entire circuit in operational.
Fig.3.11-Capacitor
3.2.5 CRYSTAL OSCILLATOR
Acrystal oscillatoris anelectronic oscillatorcircuit that uses
the mechanicalresonanceof a vibratingcrystalofpiezoelectric
materialto create an electrical signal with a very
precisefrequency. This frequency is commonly used to keep track of
time (as inquartz wristwatches), to provide a stableclock
signalfordigitalintegrated circuits, and to stabilize frequencies
forradio transmittersandreceivers. The most common type of
piezoelectric resonator used is thequartz crystal, so oscillator
circuits designed around them became known as "crystal
oscillators."
Fig.3.12-Crystal oscillator
3.2.6 RESISTANCE
Resistance is the opposition of a material to the current. It is
measured in Ohms . All conductors represent a certain amount of
resistance, since no conductor is 100% efficient. To control the
electron flow (current) in a predictable manner, we use resistors.
Electronic circuits use calibrated lumped resistance to control the
flow of current. Broadly speaking, resistor can be divided into two
groups viz. fixed & adjustable (variable) resistors. In fixed
resistors, the value is fixed & cannot be varied. In variable
resistors, the resistance value can be varied by an adjuster knob.
It can be divided into (a) Carbon composition (b) Wire wound (c)
Special type. The most common type of resistors used in our
projects is carbon type. The resistance value is normally indicated
by colour bands. Each resistance has four colours, one of the band
on either side will be gold or silver, this is called fourth band
and indicates the tolerance, others three band will give the value
of resistance (see table). For example if a resistor has the
following marking on it say red, violet, gold. Comparing these
coloured rings with the colour code, its value is 27000 ohms or 27
kilo ohms and its tolerance is 5%. Resistor comes in various sizes
(Power rating). The bigger, the size, the more power rating of 1/4
watts. The four colour rings on its body tells us the value of
resistor value as given below.
Fig.3.13-Resistance
COLOURS CODE
Black0Brown1Red2Orange3Yellow4Green5Blue6Violet7Grey8White9
The first rings give the first digit. The second ring gives the
second digit. The third ring indicates the number of zeroes to be
placed after the digits. The fourth ring gives tolerance (gold 5%,
silver 10%, No colour 20%).In variable resistors, we have the dial
type of resistance boxes. There is a knob with a metal pointer.
This presses over brass pieces placed along a circle with some
space b/w each of them.Resistance coils of different values are
connected b/w the gaps. When the knob is rotated, the pointer also
moves over the brass pieces. If a gap is skipped over, its
resistance is included in the circuit. If two gaps are skipped
over, the resistances of both together are included in the circuit
and so on. A dial type of resistance box contains many dials
depending upon the range, which it has to cover. If a resistance
box has to read upto 10,000, it will have three dials each having
ten gaps i.e. ten resistance coils each of resistance 10. The third
dial will have ten resistances each of 100.The dial type of
resistance boxes is better because the contact resistance in this
case is small & constant.
3.2.7 LED
When a junction diode is forward biased, energy is released at
the junction diode is forward biased, energy is released at the
junction due to recombination of electrons and holes. In case of
silicon and germanium diodes, the energy released is in infrared
region. In the junction diode made of gallium arsenate or indium
phosphide, the energy is released in visible region. Such a
junction diode is called a light emitting diode or LED.
Fig.3.14-LED
TYPICAL SPEC. OF HB LED 1 Watt LED Full intensity 350mA, Maximum
current 500mA2.8V Volt drop @ 350mA.
3 Watt LED Full intensity 700mA, Maximum current 1A43V Volt drop
@ 700mA.
5 Watt LED (multi-die package)Full intensity 700mA, Maximum
current 1A 7.1V Volt drop @ 700mA.
5 Watt LED (single-die)Full intensity 1.5A.
CHARACTERISTICS OF LEDs
Forward Voltage (VF) drop across LED Diodes are current
driven!
Wavelength variations Crystal and junction growth defects
Brightness variations Crystal defects resulting formation of
phonons and non-radiation energy transfer
Temperature Junction temperature of the device affects each of
the parameters above
3.2.8 LCDIt is a liquid crystal display of thin flat panel used
for electronically displaying information such as text, images and
moving pictures.
Fig.3.15-LCD
FEATURES
5 x 8 dots with cursor
Built-in controller (KS 0066 or Equivalent)
+ 5V power supply (Also available for + 3V) 1/16 duty cycle
B/L to be driven by pin 1, pin 2 or pin 15, pin 16 or A.K
(LED)
N.V. optional for + 3V power supply\PIN NUMBER SYMBOL
FUNCTION
1 Vss GND.
2 Vdd + 3V or + 5V.
3 Vo Contrast Adjustment.
4 RS H/L Register Select Signa.l
5 R/W H/L Read/Write Signal.
6 E H L Enable Signal.
7 DB0 H/L Data Bus Line.
8 DB1 H/L Data Bus Line.
9 DB2 H/L Data Bus Line.
10 DB3 H/L Data Bus Line.
11 DB4 H/L Data Bus Line.
12 DB5 H/L Data Bus Line.
13 DB6 H/L Data Bus Line.
14 DB7 H/L Data Bus Line.
15 A/Vee + 4.2V for LED/Negative Voltage Output.
3.3 INTRODUCTION TO GSM What is GSM? To G Global system for
mobile communication (GSM) is a wide area wireless communications
system that uses digital radio transmission to provide voice, data,
and multimedia communication services. A GSM system coordinates the
communication between a mobile telephones (mobile stations), base
stations (cell sites), and switching systems. Each GSM radio
channel is 200 kHz wide channels that are further divided into
frames that hold 8 time slots. GSM was originally named Group
Special Mobile. The GSM system includes mobile telephones (mobile
stations), radio towers (base stations), and interconnecting
switching systems.This figure shows an overview of a GSM radio
system. This diagram shows that the GSM system includes mobile
communication devices that communicate through base stations (BS)
and a mobile switching center (MSC) to connect to other mobile
telephones, public telephones, or to the Internet. This diagram
shows that the MSC connects to databases of customers. This example
shows that the GSM system mobile devices can include mobile
telephones or data communication devices such as laptop
computers.
Fig.3.16- Global System for Mobile Communication - GSM System
Diagram
Global System for Mobile Communication - GSM System DiagramThis
diagram shows that the GSM system uses a single type of radio
channel. Each radio channel in the GSM system has a frequency
bandwidth of 200 kHz and a data transmission rate of approximately
270 kbps. This example shows that each radio communication channel
is divided into 8 time slots (0 through 7). This diagram shows that
a simultaneous two-way voice communication session requires at
least one radio channel communicates from the base station to the
mobile station (called the forward channel) and one channel
communicates from the mobile station to the base station (called
the reverse channel). This example also shows that some of the
radio channel capacity is used to transfer voice (traffic)
information and some of the radio channel capacity is used to
transfer control messages.
GSM Radio Channel Structure DiFig.3.17-GSM Radio Channel
Structure Diagram
What are AT commands?AT Commands:AT commands are instructions
used to control a modem. AT is the abbreviation of attention. Every
command line starts with "AT" or "at". That's why modem commands
are called AT commands. Many of the commands that are used to
control wired dial-up modems, such as ATD (Dial), ATA (Answer), ATH
(Hook control) and ATO (Return to online data state), are also
supported by GSM/GPRS modems and mobile phones. Besides this common
AT command set, GSM/GPRS modems and mobile phones support an AT
command set that is specific to the GSM technology, which includes
SMS-related commands like AT+CMGS (Send SMS message), AT+CMSS (Send
SMS message from storage), AT+CMGL (List SMS messages) and AT+CMGR
(Read SMS messages).Note that the starting "AT" is the prefix that
informs the modem about the start of a command line. It is not part
of the AT command name. For example, D is the actual AT command
name in ATD and +CMGS is the actual AT command name in AT+CMGS.
However, some books and web sites use them interchangeably as the
name of an AT command.
Here are some of the tasks that can be done using AT commands
with a GSM/GPRS modem or mobile phone Get basic information about
the mobile phone or GSM/GPRS modem. For example, name of
manufacturer (AT+CGMI), model number (AT+CGMM), IMEI number
(International Mobile Equipment Identity) (AT+CGSN) and software
version (AT+CGMR). Get basic information about the subscriber. For
example, MSISDN (AT+CNUM) and IMSI number (International Mobile
Subscriber Identity) (AT+CIMI). Get the current status of the
mobile phone or GSM/GPRS modem. For example, mobile phone activity
status (AT+CPAS), mobile network registration status (AT+CREG),
radio signal strength (AT+CSQ), battery charge level and battery
charging status (AT+CBC). Establish a data connection or voice
connection to a remote modem (ATD, ATA, etc). Send and receive fax
(ATD, ATA, AT+F*). Send (AT+CMGS, AT+CMSS), read (AT+CMGR,
AT+CMGL), write (AT+CMGW) or delete (AT+CMGD) SMS messages and
obtain notifications of newly received SMS messages (AT+CNMI). Read
(AT+CPBR), write (AT+CPBW) or search (AT+CPBF) phonebook entries.
Perform security-related tasks, such as opening or closing facility
locks (AT+CLCK), checking whether a facility is locked (AT+CLCK)
and changing passwords (AT+CPWD).Control the presentation of result
codes / error messages of AT commands. For example, you can control
whether to enable certain error messages (AT+CMEE) and whether
error messages should be displayed in numeric format or verbose
format (AT+CMEE=1 or AT+CMEE=2). Get or change the configurations
of the mobile phone or GSM/GPRS modem. For example, change the GSM
network (AT+COPS), bearer service type (AT+CBST), radio link
protocol parameters (AT+CRLP), SMS center address (AT+CSCA) and
storage of SMS messages (AT+CPMS). Save and restore configurations
of the mobile phone or GSM/GPRS modem. For example, save (AT+CSAS)
and restore (AT+CRES) settings related to SMS messaging such as the
SMS center address.
Benefits of GSM1. EmergencyResponse.112 is now a universal
emergency number among GSM networks. No matter where the user is,
if they are using GSM, they can call for help.2. Technological
GrowthThe growth of communications technology has been prompted by
worldwide competition, allowed by the universality of GSM. This has
lead to a reliable cell-phone service and improved quality in both
connection stability and ease. 3. Universal Data TransferThe Global
System for Mobile Communications allows for reliable and efficient
data transfer. It even allows text and pictures to be sent from
anywhere the system is available.4. Better sound As digital
carrier, a GSM cell phone makes for clearer connections as it can
filter background noise. This makes communication, despite distance
easy.5. Greater Security Due to the way its designed, a call needs
to request access. This is a safety features that makes sure that
only the caller and the receiver are in the conversation.
APPLICATION
Voting Machine Home Appliance Control Robot Control E-Notice
Board
CHAPTER 4SOFTWARE DESCRIPTION
4 INTRODUCTION The software used in this project is KEIL u
Version3.Keil Software to provide you with software development
tools for 8051 based microcontrollers. With the Keil tools, you can
generate embedded applications for virtually every 8051 derivative.
The supported microcontrollers are listed in the Vision Device
Database.The Keil Software 8051 development tools are designed for
the professional software developer, but any level of programmer
can use them to get the most out of the 8051 microcontroller
architecture.
Keil software converts the C-codes into the Intel Hex code.
The coding used in this project is as follows: void
lcdinit(void); void lcdData(unsigned char l); void lcdcmd(unsigned
char k); void DelayMs(unsigned int count); void InitModem(void);
void initdisplay(void); //---------------------------------------
// Lcd initialization subroutine
//--------------------------------------- void lcdinit(void) {
lcdcmd(0x38); DelayMs(250); lcdcmd(0x0C); DelayMs(250);
lcdcmd(0x01); DelayMs(250); lcdcmd(0x06); DelayMs(250);
lcdcmd(0x80); DelayMs(250); }
//--------------------------------------- // Lcd data display
//--------------------------------------- void lcdData(unsigned
char l) { LCD_PORT=l; RS=1; EN=1; DelayMs(1); EN=0; return; }
//--------------------------------------- // Lcd command
//--------------------------------------- void lcdcmd(unsigned char
k) { LCD_PORT=k; RS=0; EN=1; DelayMs(1); EN=0; return; }
CHAPTER 5CONCLUSION
5.1 Conclusion
The project MOBILE CONTROLLED IRRIGATION SYSTEM has been
successfully designed and tested. Integrating features of all the
hardware components used have developed it. Presence of every
module has been reasoned out and placed carefully thus contributing
to the best working of the unit. Secondly, using highly advanced
ICs and with the help of growing technology the project has been
successfully implemented. Embedded systems are emerging as a
technology with high potential. In the past decades micro processor
based embedded system ruled the market. The last decade witnessed
the revolution of Microcontroller based embedded systems.. With
regards to the requirements gathered the manual work and the
complexity in counting can be achieved with the help of electronic
devices.
BIBLIOGRAPHY
NAME OF THE SITES
1. WWW.MITEL.DATABOOK.COM2. WWW.ATMEL.DATABOOK.COM3.
WWW.FRANKLIN.COM4. WWW.KEIL.COM
REFERENCES
1. 8051-MICROCONTROLLER AND EMBEDDED SYSTEM.Mohd. Mazidi.
2. EMBEDDED SOFTWARE PRIMER.David .E. Simon.
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