AUTOMATIC PLANT IRRIGATION SYSTEM

A PROJECT REPORT

Submitted by

AMIT YADAV(08-TIB-1160)

RAHUL DEV(08-TIB-1135)

RAVINDER KUMAR(08-TIB-1166)

SHWETANK SINGH(08-TIB-1144)

submitted in the partial fulfillment of the requirements for the award of degree

of

Bachelor of Technology

IN

Electronics & Communication Engineering

The Technological Institute of Textile and Sciences, Bhiwani

MAHARISHI DAYANAND UNIVERSITY,ROHTAK

(2008-12)

Department of Electronics and Communication

CERTIFICATE OF APPROVAL

The foregoing project work report entitled “AUTOMATIC PLANT

IRRIGATION SYSTEM” is a hereby approved as a creditable work and has

been presented in a satisfactory manner to warrant its acceptance as prerequisite to

the degree for which it has been submitted.

It is understood that for this approval ,the undersigned do not necessarily endorse

any conclusion drawn or opinion expressed therein, but approve the project work

for the purpose for which it is submitted.

(Internal Examiner) (External Examiner)

(Head of the Department)

The Technological Institute of Textile and Sciences,

Bhiwani

CERTIFICATE

This is to certify that the work presented in the project report entitled

“AUTOMATIC PLANT IRRIGATION SYSTEM” in the partial fulfillment

of the requirement for the award of Degree of Bachelor of Technology in

Electronics and Communication of The Technological Institute of Textile and

Sciences, Bhiwani is an authentic work carried out under my supervision and

guidance.

To the best of my knowledge ,the content of this project work not form a basis for

the award of any previous Degree to any one else.

Date:

Mr. Vikram Singh Mr. S.K.Jha

( Project Guide ) ( Project Coordinator )

Mr. Kamal Sardana

( Head of the Department )

ACKNOWLEDGEMENT

Knowledge is an experience gained in life. It is the choicest possession,which should not be

shelved but should be happily shared with others. In this regard We are extremely fortunate in

having Mr. Vikram Sing as my project guide .It was he ,who provided proper direction in the

completion of this project work.

I have often been guilty of encroaching upon the privacy of this home but not even once We were

disappointed .His willingness to share his experience and spontaneous suggestion on any

problem encourage me tremendously to achieve my goal .We are sure his directive will show us

the light in future also.

We are very much thankful to Mr. Kamal Sardana ,HOD ,ECE deptt for his

encouragement ,valuable suggestion and moral support provided by him.

At the juncture,We feel at the deepest of our heart to acknowledge the encouragement and

blessing of our mother and sister.

Last but not the least ,words can hardly express our heartfelt gratitude towards our project

coordinator(Mr. S. K. Jha) ,who stood by us and helped in every way possible during the

completion of this project.

Amit Yadav(08ec058)

Rahul Dev(08ec026)

Ravinder Kumar(08ec028)

Shwetank Singh(08ec041)

ABSTRACT

The project we have undertaken is “Automatic Plant Irrigation System”. This

project is taken up as India is an agriculture oriented country and the rate at which

water resources are depleting is a dangerous threat hence there is a need of smart

and efficient way of irrigation. In this project we have implemented sensors which

detect the humidity in the soil (agricultural field) and supply water to the field

which has water requirement. The project is 8051 microcontroller based design

which controls the water supply and the field to be irrigated. There are sensors

present in each field which are not activated till water is present on the field. Once

the field gets dry sensors sense the requirement of water in the field and send a

signal to the microcontroller. Microcontroller then supply water to that particular

field which has water requirement till the sensors is deactivated again. In case,

when there are more than one signal for water requirement then the microcontroller

will prioritize the first received signal and irrigate the fields accordingly.

TABLE OF CONTENTS

Abstract

TITLE

1. INTRODUCTION

2. WORKING

2.1 CIRCUIT DIAGRAM

2.2 CIRCUIT DESCRIPTION

2.2.1 COMPONENT LIST

2.2.2 COMPONENT DESRIPTION

2.3 INTRODUCTION TO 8051 µCONTROLLER

2.4 BASICS OF µCONTROLLER

2.5 BLOCK DIAGRAM OF 8051

2.6 WORKING OF PROJECT

3. PROCEDURE ADOPTED

3.1 PCB DESIGNING

3.2 COMPONENT MOUNTING ON PCB

3.2.1 TOOLS USED

3.3 BURNING HEX CODE TO MICROCONTROLLER

3.3.1 SOFTWARE USED

3.3.2 C PROGRAM FILE

4. APPLICATIONS

5. REFERENCES

6. EXTENTIONS IN THE PROJECT FOR 8th SEMESTER

INTRODUCTION

In the fast paced world human beings require everything to be automated. Our life

style demands everything to be remote controlled. Apart from few things man has

made his life automated. And why not ? In the world of advance electronics, life of

human beings should be simpler hence to make life more simpler and convenient,

we have made “AUTOMATIC PLANT IRRIGATION SYSTEM”. A model of

controlling irrigation facilities to help millions of people. This model uses sensor

technology with microcontroller to make a smart switching device .

The model shows the basic switching mechanism of Water motor/pump using

sensors from any part of field by sensing the moisture present in the soil. Our basic

model can be extended to any level of switching & controlling by using DTMF .

WORKING

CIRCUIT DIAGRAMS:

1). MICROCONTROLLER UNIT

2).POWER SUPPLY UNIT

3).SENSOR CKT. DIAGRAMS

CIRCUIT DESCRIPTION

COMPONENT S LIST

Transformer : Step down transformer (220/12)

Voltage Regulator : IC 7805

Op-amp : LM741

Crystal oscillator : 11.0592 M Hz

Diode : IN 4007

LED

Resistor : 470 ohm (for LED) , 8.2 K (for power on reset

C kt. ), 10 K (for sensors) , potentiometer(100K)

Capacitor : 1000 u f (for Power supply),10 u f ( reset ckt.)

33p F( for crystal oscillator)

LCD : 16 x 2

Stepper motor : step angle 7.5 degree, +12V

Relay : 220V/3-4A

Microcontroller : AT89S52

ULN : ULN 2003

Water pump

Switches

Power cables & ribbon wires

COMPONENT DESCRIPTION

STEP DOWN TRANSFORMER

Power supply is a reference to a source of electrical power. A device or system that supplies

electrical or other types of energy to an output load or group of loads is called a power

supply unit or PSU. The term is most commonly applied to electrical energy supplies, less

often to mechanical ones, and rarely to others.

Here in our application we need a 5v DC power supply for all electronics involved in the

project. This requires step down transformer, rectifier, voltage regulator, and filter circuit for

generation of 5v DC power. Here a brief description of all the components are given as fol-

lows:

VOLTAGE REGULATOR IC 7805

This is most common voltage regulator that is still used in embedded designs. LM7805 voltage

regulator is a linear regulator made by several manufacturers like Fairchild, or ST Microelectron-

ics. They can come in several types of packages. For output current up to 1A there may be two

types of packages: TO-220 (vertical) and D-PAK (horizontal).

With proper heat sink these LM78xx types can handle even more than 1A current. They also

have Thermal overload protection, Short circuit protection.

If your design won’t exceed 0.1A current you may chose regulator LM78L05 with smaller

packages and lower maximum current up to 0.1A. They come in three main types of packages

SO-8, SOT-89 and TO-92

OP-AMP

An operational amplifier ("op-amp") is a DC-coupled high-gain electronic voltage amplifier

with a differential input and, usually, a single-ended output. An op-amp produces an output volt-

age that is typically hundreds of thousands times larger than the voltage difference between its

input terminals.

Operational amplifiers are important building blocks for a wide range of electronic circuits. They

had their origins in analog computers where they were used in many linear, non-linear and fre-

quency-dependent circuits. Their popularity in circuit design largely stems from the fact that

characteristics of the final op-amp circuits with negative feedback (such as their gain) are set by

external components with little dependence on temperature changes and manufacturing varia-

tions in the op-amp itself.

Op-amps are among the most widely used electronic devices today, being used in a vast array of

consumer, industrial, and scientific devices. Many standard IC op-amps cost only a few cents in

moderate production volume; however some integrated or hybrid operational amplifiers with

special performance specifications may cost over $100 US in small quantities. Op-amps may be

packaged as components, or used as elements of more complex integrated circuits.

The op-amp is one type of differential amplifier. Other types of differential amplifier include the

fully differential amplifier (similar to the op-amp, but with two outputs), the instrumentation am-

plifier (usually built from three op-amps), the isolation amplifier (similar to the instrumentation

amplifier, but with tolerance to common-mode voltages that would destroy an ordinary op-amp),

and negative feedback amplifier (usually built from one or more op-amps and a resistive feed-

back network).

PIN CONFIGURATION

CIRCUIT NOTATION

V+: non-inverting input

V−: inverting input

Vout: output

VS+: positive power supply

VS−: negative power supply

CRYSTAL OSCILLATOR

IMAGE SYMBOL

A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vi-

brating crystal of piezoelectric material to create an electrical signal with a very precise fre-

quency. This frequency is commonly used to keep track of time (as in quartz wristwatches), to

provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio

transmitters and receivers. The most common type of piezoelectric resonator used is the quartz

crystal, so oscillator circuits designed around them became known as "crystal oscillators."

Quartz crystals are manufactured for frequencies from a few tens of kilohertz to tens of mega-

hertz. More than two billion (2×109) crystals are manufactured annually. Most are used for con-

sumer devices such as wristwatches, clocks, radios, computers, and cellphones. Quartz crystals

are also found inside test and measurement equipment, such as counters, signal generators, and

oscilloscopes.

DIODE

SYMBOL

The 1N4007 series (or 1N4000 series) is a family of popular 1.0 amp general purpose silicon

rectifier diodes commonly used in AC adapters for common household appliances. Blocking

voltage varies from 50 to 1000 volts. This diode is made in an axial-lead DO-41 plastic package.

The 1N5400 series is a similarly popular series for higher current applications, up to 3 A. These

diodes come in the larger DO-201 axial package.

These are fairly low-speed rectifier diodes, being inefficient for square waves of more than 15

kHz. The series was second sourced by many manufacturers. The 1N4000 series were in the Mo-

torola Silicon Rectifier Handbook in 1966, as replacements for 1N2609 through 1N2617. The

1N5400 series were announced in Electrical Design News in 1968, along with the now lesser

known 1.5-ampere 1N5391 series.

These devices are widely used and recommended. The table below shows the maximum repeti-

tive reverse blocking voltages of each of the members of the 1N4000 and 1N5400 series

IMAGE OF DIODES

LED

A light-emitting diode (LED) is a semiconductor device that emits visible light when an electric

current passes through it. The light is not particularly bright, but in most LEDs it is monochro-

matic, occurring at a single wavelength. The output from an LED can range from red (at a wave-

length of approximately 700 nanometers) to blue-violet (about 400 nanometers). Some LEDs

emit infrared (IR) energy (830 nanometers or longer); such a device is known as an infrared-

emitting diode (IRED). An LED or IRED consists of two elements of processed material called

P-type semiconductors and N-type semiconductors. These two elements are placed in direct con-

tact, forming a region called the P-N junction. In this respect, the LED or IRED resembles most

other diode types, but there are important differences. The LED or IRED has a transparent pack-

age, allowing visible or IR energy to pass through. Also, the LED or IRED has a large PN-junc-

tion area whose shape is tailored to the application.

Benefits of LEDs

Low power requirement: Most types can be operated with battery powersupplies.

High efficiency: Most of the power supplied to an LED or IRED isconverted into radiation in

the desired form, with minimal heat production.

Long life: When properly installed, an LED or IRED can function for

decades.

RESISTOR

A resistor is an electrical component that limits or regulates the flow of electrical current in an

electronic circuit. Resistors can also be used to provide a specific voltage for an active device

such as a transistor. All other factors being equal, in a direct-current (DC) circuit, the current

through a resistor is inversely proportional to its resistance, and directly proportional to the

voltage across it. This is the well-known Ohm's Law. In alternating-current (AC) circuits, this

rule also applies as long as the resistor does not contain inductance or capacitance.

Resistors can be fabricated in a variety of ways. The most common type inelectronic devices and

systems is the carbon-composition resistor. Finegr anulated carbon (graphite) is mixed with clay

and hardened. The resistance depends on the proportion of carbon to clay; the higher this ratio,

the lower the resistance.

Another type of resistor is made from winding Nichrome or similar wire onan insulating form.

This component, called a wire wound resistor, is able to handle higher currents than a carbon-

composition resistor of the same physical size. However, because the wire is wound into a coil,

the component acts as an inductors as well as exhibiting resistance. This does not affect perfor-

mance in DC circuits, but can have an adverse effect in AC circuits because inductance renders

the device sensitive to changes in output.

CAPACITOR

A capacitor is a tool consisting of two conductive plates, each of which hosts an opposite charge.

These plates are separated by a dielectric or other form of insulator, which helps them maintain

an electric charge. There are several types of insulators used in capacitors. Examples include ce-

ramic, polyester, tantalum air, and polystyrene. Other common capacitor insulators include air,

paper, and plastic. Each effectively prevents the plates from touching each other. A capacitor is

often used to store analogue signals and digital data. Another type of capacitor is used in the

telecommunications equipment industry. This type of capacitor is able to adjust the frequency

and tuning of telecommunications equipment and is often referred to a variable capacitor. A ca-

pacitor is also ideal for storing an electron. A capacitor cannot, however, make electrons. A ca-

pacitor measures in voltage, which differs on each of the two interior plates. Both plates of the

capacitor are charged, but the current flows in opposite directions. A capacitor contains 1.5 volts,

which is the same voltage found in a common AA battery. As voltage is used in a capacitor, one

of the two plates becomes filled with a steady flow of current. At the same time, the current

flows away from the other plate. To understand the flow of voltage in a capacitor, it is helpful to

look at naturally occurring examples. Lightning, for example, is similar to a capacitor. The cloud

represents one of the plates and the ground represents the other. The lightning is the charging

factor moving between the ground and the cloud.

IMAGE OF ELECTROLYTIC CAPACITOR

UNPOLARISED / CERAMIC CAPACITORS

A non-polarized ("non polar") capacitor is a type of capacitor that has no implicit polarity -- it

can be connected either way in a circuit. Ceramic, mica and some electrolytic capacitors are non-

polarized. You'll also sometimes hear people call them "bipolar" capacitors.

SYMBOL

IMAGE OF CERAMIC CAPACITOR

LCD

Liquid Crystal Display

Liquid crystal displays (LCD) are widely used in recent years as compares to LEDs. This is due

to the declining prices of LCD, the ability to display numbers, characters and graphics,

incorporation of a refreshing controller into the LCD, their by relieving the CPU of the task of

refreshing the LCD and also the ease of programming for characters and graphics. HD 44780

based LCDs are most commonly used.

LCD pin description

The LCD discuss in this section has the most common connector used for the Hitatchi 44780

based LCD is 14 pins in a row and modes of operation and how to program and interface with

microcontroller is describes in this section.

D7

The voltage VCC and VSS provided by +5V and ground respectively while VEE is used for

controlling LCD contrast. Variable voltage between Ground and Vcc is used to specify the

contrast (or "darkness") of the characters on the LCD screen.

RS (register select)

There are two important registers inside the LCD. The RS pin is used for their selection as

follows. If RS=0, the instruction command code register is selected, then allowing to user to send

a command such as clear display, cursor at home etc.. If RS=1, the data register is selected,

allowing the user to send data to be displayed on the LCD.

R/W (read/write)

The R/W (read/write) input allowing the user to write information from it. R/W=1, when it read

and R/W=0, when it writing.

EN (enable)

The enable pin is used by the LCD to latch information presented to its data pins. When data is

supplied to data pins, a high power, a high-to-low pulse must be applied to this pin in order to for

the LCD to latch in the data presented at the data pins.

D0-D7 (data lines)

The 8-bit data pins, D0-D7, are used to send information to the LCD or read the contents of the

LCD‘s internal registers. To displays the letters and numbers, we send ASCII codes for the

letters A-Z, a-z, and numbers 0-9 to these pins while making RS =1. There are also command

codes that can be sent to clear the display or force the cursor to the home position or blink the

cursor. We also use RS =0 to check the busy flag bit to see if the LCD is ready to receive the

information. The busy flag is D7 and can be read when R/W =1 and RS =0, as follows:

if R/W =1 and RS =0, when D7 =1(busy flag =1), the LCD is busy taking care of internal

operations and will not accept any information. When D7 =0, the LCD is ready to receive new

information.

CODES COMMAND TO LCD INSTRUCTION

(HEX) Register

1 Clear display screen

2 Return home

4 Decrement cursor(shift cursor to left)

6 Increment cursor(shift cursor to right)

5 Shift display right

7 Shift display left

8 Display off, cursor off

A Display off, cursor on

C Display on, cursor off

E Display on, cursor blinking

F Display on, cursor blinking

10 Shift cursor position to left

14 Shift cursor position to right

18 Shift the entire display to the left

1C Shift the entire display to the right

80 Force cursor to beginning of 1st line

C0 Force cursor to beginning of 2nd line

38 2 line and 5x 7 matrix

Pin Symbol I/O Description

1 VSS - Ground

2 VCC - +5V power supply

3 VEE - Power supply to control contrast

4 RS I RS=0 to select command register, RS=1 to select data register.

5 R/W I R/W=0 for write, R/W=1 for read

6 E I/O Enable

7 PB0 I/O The 8 bit data bus

8 PB1 I/O The 8 bit data bus

9 DB2 I/O The 8 bit data bus

10 DB3 I/O The 8 bit data bus

11 DB4 I/O The 8 bit data bus

12 DB5 I/O The 8 bit data bus

13 DB6 I/O The 8 bit data bus

14 DB7 I/O The 8 bit data bus

STEPPER MOTOR

Motion Control, in electronic terms, means to accurately control the movement of an object

based on either speed, distance, load, inertia or a combination of all these factors. There are

numerous types of motion control systems, including; Stepper Motor, Linear Step Motor, DC

Brush, Brushless, Servo, Brushless Servo and more.

A stepper motor is an electromechanical device which converts electrical pulses into discrete

mechanical movements. Stepper motor is a form of ac. motor .The shaft or spindle of a stepper

motor rotates in discrete step increments when electrical command pulses are applied to it in the

proper sequence. The motors rotation has several direct relationships to these applied input

pulses. The sequence of the applied pulses is directly related to the direction of motor shafts

rotation. The speed of the motor shafts rotation is directly related to the frequency of the input

pulses and the length of rotation is directly related to the number of input pulses applied.

For every input pulse, the motor shaft turns through a specified number of degrees, called

a step. Its working principle is one step rotation for one input pulse. The range of step size may

vary from 0.72 degree to 90 degree. In position control application, if the number of input pulses

sent to the motor is known, the actual position of the driven job can be obtained.

A stepper motor differs from a conventional motor (CM) as under:

a. Input to SM is in the form of electric pulses whereas input to a CM is invariably from a

constant voltage source.

b. A CM has a free running shaft whereas shaft of SM moves through angular steps.

c. In control system applications, no feedback loop is required when SM is used but a

feedback loop is required when CM is used.

d. A SM is a digital electromechanical device whereas a CM is an analog electromechanical

device .

Step Angle & Steps per Revolution

Movement associated with a single step, depends on the internal construction of the motor, in

particular the number of teeth on the stator and the rotor. The step angle is the minimum degree

of rotation associated with a single step.

Step per revolution is the total number of steps needed to rotate one complete rotation or 360

degrees (e.g., 180 steps * 2 degree = 360)

Since the stepper motor is not ordinary motor and has four separate coils, which have to

be energized one by one in a stepwise fashion. We term them as coil A, B, C and D. At a

particular instant the coil A should get supply and then after some delay the coil B should get a

supply and then coil C and then coil D and so on the cycle continues. The more the delay is

introduced between the energizing of the coils the lesser is the speed of the stepper motor and

vice versa.

RELAY

The electromagnetic relay consists of a multi-turn coil, wound on an iron core, to form an

electromagnet. When the coil is energised, by passing current through it, the core becomes

temporarily magnetised. The magnetised core attracts the iron armature. The armature is pivoted

which causes it to operate one or more sets of contacts.When the coil is de-energised the

armature and contacts are released. The coil can be energised from a low power source such as a

transistor while the contacts can switch high powers such as the mains supply. The relay can also

be situated remotely from the control source. Relays can generate a very high voltage across the

coil when switched off.This can damage other components in the circuit. To prevent this a diode

is connected across the coil.

As there are always some chances of high voltage spikes back from the switching circuit i.e.

heater so an optocoupler/isolator MCT2e is used. It provides and electrical isolation between the

microcontroller and the heater. MCT2e is a 6-pin IC with a combination of optical transmitter

LED and an optical receiver as phototransistor. Microcontroller is connected to pin no 2 of

MCT2e through a 470-ohm resistor. Pin no.1 is given +5V supply and pin no.4 is grounded. To

handle the current drawn by the heater a power transistor BC-369 is used as a current driver. Pin

no.5 of optocoupler is connected to the base of transistor. It takes all it‘s output to V cc and

activates the heater through relay circuit. The electromagnetic relay consists of a multi-turn coil,

wound on an iron core, to form an electromagnet. When the coil is energized, by passing current

through it, the core becomes temporarily magnetized. The magnetized core attracts the iron

armature. The armature is pivoted which causes it to operate one or more sets of contacts. When

the coil is de-energised the armature and contacts are released. Relays can generate a very high

voltage across the coil when switched off. This can damage other components in the circuit. To

prevent this a diode is connected across the coil. Relay has five points. Out of the 2 operating

points one is permanently connected to the ground and the other point is connected to the

collector side of the power transistor. When Vcc reaches the collector side i.e. signal is given to

the operating points the coil gets magnetized and attracts the iron armature. The iron plate moves

from normally connected (NC) position to normally open (NO) position. Thus the heater gets the

phase signal and is ON. To remove the base leakage voltage when no signal is present a 470-ohm

resistance is used.

ULN 2003A

I. SEVEN DARLINGTONS PER PACKAGE OUTPUT CURRENT 500mA PER

DRIVER

II. (600mA PEAK)

III. OUTPUT VOLTAGE 50V INTEGRATED SUPPRESSION DIODES FOR

IV. INDUCTIVE LOADS OUTPUTS CAN BE PARALLELED FOR HIGHER CURRENT

V. TTL/CMOS/PMOS/DTL COMPATIBLE INPUTS INPUTS PINNED OPPOSITE OUT-

PUTS TO SIMPLIFY LAYOUT

DESCRIPTION

PIN CONFIGURATION

The ULN2001A, ULN2002A, ULN2003 andULN2004A are high voltage, high current darling-

ton

arrays each containing seven open collector darlingtonpairs with common emitters. Each channel

rated at 500mA and can withstand peak currents of 600mA. Suppression diodes are included for

inductive load driving and the inputs are pinned opposite the outputs to simplify board layout.

The four versions interface to all common logic families

a) ULN2001A General Purpose, DTL, TTL, PMOS,CMOS

b) ULN2002A 14-25V PMOS

c) ULN2003A 5V TTL, CMOS

d) ULN2004A 6–15V CMOS, PMOS

These versatile devices are useful for driving a wide range of loads including solenoids, relays

DC motors, LED displays filament lamps, thermal printheads and high power buffers. The UL-

N2001A/2002A/2003A and 2004A are supplied in 16 pin plastic DIP packages with a copper

leadframe to reduce thermal resistance. They are available also in small outline package (SO-16)

as ULN2001D/2002D/2003D/2004D.

INTRODUCTION TO 8051 µCONTROLLER

The Intel 8051 is an 8-bit microcontroller which means that most available operations are limited

to 8 bits. There are 3 basic "sizes" of the 8051: Short, Standard, and Extended. The Short and

Standard chips are often available in DIP (dual in-line package) form, but the Extended 8051

models often have a different form factor, and are not "drop-in compatible". All these things are

called 8051 because they can all be programmed using 8051 assembly language, and they all

share certain features (although the different models all have their own special features).

Some of the features that have made the 8051 popular are:

4 KB on chip program memory.

128 bytes on chip data memory(RAM).

4 reg banks.

128 user defined software flags.

8-bit data bus

16-bit address bus

32 general purpose registers each of 8 bits

16 bit timers (usually 2, but may have more, or less).

3 internal and 2 external interrupts.

Bit as well as byte addressable RAM area of 16 bytes.

Four 8-bit ports, (short models have two 8-bit ports).

16-bit program counter and data pointer.

1 Microsecond instruction cycle with 12 MHz Crystal.

8051 models may also have a number of special, model-specific features, such as UARTs, ADC,

OpAmps, etc...

PIN CONFIGURATION

PIN 9: PIN 9 is the reset pin which is used reset the microcontroller’s internal registers and ports

upon starting up. (Pin should be held high for 2 machine cycles.)

PINS 18 & 19: The 8051 has a built-in oscillator amplifier hence we need to only connect a

crystal at these pins to provide clock pulses to the circuit.

PIN 40 and 20: Pins 40 and 20 are VCC and ground respectively. The 8051 chip needs +5V

500mA to function properly, although there are lower powered versions like the Atmel 2051

which is a scaled down version of the 8051 which runs on +3V.

PINS 29, 30 & 31: As described in the features of the 8051, this chip contains a built-in flash

memory. In order to program this we need to supply a voltage of +12V at pin 31. If external

memory is connected then PIN 31, also called EA/VPP, should be connected to ground to indi -

cate the presence of external memory. PIN 30 is called ALE (address latch enable), which is used

when multiple memory chips are connected to the controller and only one of them needs to be

selected.We will deal with this in depth in the later chapters. PIN 29 is called PSEN. This is

"program store enable". In order to use the external memory it is required to provide the low

voltage (0) on both PSEN and EA pins.

There are 4 8-bit ports: P0, P1, P2 and P3.

PORT P1 (Pins 1 to 8): The port P1 is a general purpose input/output port which can be used for

a variety of interfacing tasks. The other ports P0, P2 and P3 have dual roles or additional func-

tions associated with them based upon the context of their usage.

PORT P3 (Pins 10 to 17): PORT P3 acts as a normal IO port, but Port P3 has additional func-

tions such as, serial transmit and receive pins, 2 external interrupt pins, 2 external counter inputs,

read and write pins for memory access.

PORT P2 (pins 21 to 28): PORT P2 can also be used as a general purpose 8 bit port when no

external memory is present, but if external memory access is required then PORT P2 will act as

an address bus in conjunction with PORT P0 to access external memory. PORT P2 acts as A8-

A15, as can be seen from fig 1.1

PORT P0 (pins 32 to 39) PORT P0 can be used as a general purpose 8 bit port when no external

memory is present, but if external memory access is required then PORT P0 acts as a multi-

plexed address and data bus that can be used to access external memory in conjunction with

PORT P2. P0 acts as AD0-AD7,

PIN DIAGRAM

BASICS OF µCONTROLLER

Before actually going through this tutorial let me tell you something about number systems used

in Computer Systems. As you know human know the decimal number system 1,2,3---9, but how

will computer understand our language hence we use binary system which uses 0 & 1. Comput-

ers understand the language of 0 & 1. We also have a hexadecimal system which is nothing but a

way of representing a binary number. Similarly we have a ASCII System for information sharing

between computers.

Memory inside computer system: There are Basically two types of memories RAM & ROM.

RAM as you know is Random Access Memory and data stored in it is temporary whereas ROM

is read only memory and data stored in it is permanent. CPU (Central Processing Unit is combi-

nation of ALU Arithmetic Logic Unit & Control Unit. The A.L.U. (Arithmetic and Logic Unit)

performs all the calculations.

BLOCK DIAGRAM

Data and Program Memory

The 8051 Microcontroller can be programmed in PL/M, 8051 Assembly, C and a number of

other high-level languages. Many compilers even have support for compiling C++ for an

8051.Program memory in the 8051 is read-only, while the data memory is considered to be

read/write accessible. When stored on EEPROM or Flash, the program memory can be rewritten

when the microcontroller is in the special programmer circuit.

Program Start Address

The 8051 starts executing program instructions from address 0000 in the program memory.

Direct Memory

The 8051 has 256 bytes of internal addressable RAM, although only the first 128 bytes are

available for general use by the programmer. The first 128 bytes of RAM (from 0x00 to 0x7F)

are called the Direct Memory, and can be used to store data.

Special Function Register

The Special Function Register (SFR) is the upper area of addressable memory, from address

0x80 to 0xFF. A, B, PSW, DPTR are called SFR.This area of memory cannot be used for data or

program storage, but is instead a series of memory-mapped ports and registers. All port input and

output can therefore be performed by memory mov operations on specified addresses in the SFR.

Also, different status registers are mapped into the SFR, for use in checking the status of the

8051, and changing some operational parameters of the 8051.

General Purpose Registers

The 8051 has 4 selectable banks of 8 addressable 8-bit registers, R0 to R7. This means that there

are essentially 32 available general purpose registers, although only 8 (one bank) can be directly

accessed at a time. To access the other banks, we need to change the current bank number in the

flag status register.

A and B Registers

The A register is located in the SFR memory location 0xE0. The A register works in a similar

fashion to the AX register of x86 processors. The A register is called the accumulator, and by de-

fault it receives the result of all arithmetic operations. The B register is used in a similar manner,

except that it can receive the extended answers from the multiply and divide operations. When

not being used for multiplication and Division, the B register is available as an extra general-pur-

pose register.

BLOCK DIGRAM OF 8051 µCONTROLLER

WORKING OF PROJECT

The deficiency of water in the field is sensed by the op-amp based sensor. Whenever there is

need of water in the particular field, the high signal(‘1’) appears on the output pin of the sensor

of that particular field. The output pins of all the sensors are connected to the PORT 2 of

microcontroller. The high signsl(logic 1) from the sensor is entertained by the microcontroller at

a particular pin. By knowing the position of the pin on which signal appears , the microcontroller

rotates the water funnel type cup at the desired angle (i.e. 90 ,180 ,270) by using stepper motor

connected at PORT 0 in clockwise direction. & switch ON the RELAY (i.e. Water pump)

connected at port 0. Now water starts flowing into the required field . after completion of

watering the sensor sends low signal (logic 0) to microcontroller. When uc receives this signal ,

it switches OFF the water pump & rotates the stepper motor in anticlockwise direction to the

previous angle to bring the funnel cup in its initial position . now uc starts sensing the signal at

PORT 2. Whenever there is signal at any pin the uc repeats the above process. So this process

continues & we get the automatic irrigation the fields by using intelligent device uc 8051.

PROCEDURE ADOPTED

PCB DESIGNING

STEPS TO DESIGN PCB

1. LAYOUT PREPARATION

Prepare the layout of the circuit diagram using software Proteus 7.1 / Express PCB.

Take the print out of layout on transparent sheet or butter paper in inverted format.

2. LAYOUT IMPRESSION ON CLAD BORD

Take the impression of layout on Clad board using carbon paper or electric iron.

3. ETCHING

Now dip the clad board having printed layout into the etch solution.

The etch solution removes the unwanted copper .

Now we are able to get the required layout printed on PCB in the form of copper.

4. TESTING

Now test the tracks using multimeter.

5. DRILLING/PUNCHING

Now drill the required holes for component mounting.

LAYOUTS:

MIVROCONTROLLER UNIT LAYOUT

SENSOR LAYOUT

COMPONENTS MOUNTING ON PCB

TOOLS USED:

Soldering iron

A soldering iron is a hand tool most commonly used in soldering.

It supplies heat to melt the solder so that it can flow into the joint

between two workpieces.

A soldering iron is composed of a heated metal tip and an insu-

lated handle. Heating is often achieved electrically, by passing an

electric current (supplied through an electrical cord or battery ca-

bles) through the resistive material of a heating element. Another heating method includes com-

bustion of a suitable gas, which can either be delivered through a tank mounted on the iron

(flameless), or through an external flame.

Less common uses include pyrography (burning designs into wood) and plastic welding.Solder-

ing irons are most often used for installation, repairs, and limited production work. High-volume

production lines use other soldering methods.

Wire Stripper

Wire stripper is used to strip off wire insulator from its conductor before it is used to connect to

another wire or soldered into the printed circuit board. Some wire stripper or wire cutter has a

measurement engraved on it to indicate the length that will be stripped.

Side-Cutting Plier

A 4-inch side cutting plier will come in handy as one of the elec-

tronic tools when one need to trim off excess component leads on

the printed circuit board. It can also be used to cut wires into shorter

length before being used. Tweezer

Small tweezer is used to hold small components especially when doing soldering and de-solder-

ing of surface mount components.

COMPONENT MOUNTING

Now mount all the components on the PCBs using the above mentioned tools.

SOFTWARES USED

KEIL uVision 3

The Keil 8051 Development Tools are designed to solve the complex problems facing embedded

software developers.

1) When starting a new project, simply select the microcontroller you use from the Device

Database and the µVision IDE sets all compiler, assembler, linker, and memory options

for you.

2) Numerous example programs are included to help you get started with the most popular

embedded 8051 devices.

3) The Keil µVision Debug-

ger accurately simulates

on-chip peripherals (I²C,

CAN, UART, SPI, Inter-

rupts, I/O Ports, A/D Con-

verter, D/A Converter,

and PWM Modules) of

your 8051 device. Simula-

tion helps you understand

hardware configurations

and avoids time wasted on

setup problems. Additionally, with simulation, you can write and test applications before

target hardware is available.

VARIOUS STEPS TO USE THE KEIL COMPILER

1) Open keil from the start menu.

2) Select a new project from the project menu.

3) Make a new folder in any drive.

4) Name the project as ABC and then click save.

5) Right click on target, then options for the target, then choose the device, set the crystal

frequency, click on the create hex file option to create hex file at the output.

6) Then create a new file from the file menu and save it with the same name of project using

extension .c or .asm.

7) Right clicks on the source group, then click on add files option to add the files and then

click on close.

HOW TO DEBUG THE PROGRAM

1) After writing the code, click on file menu and select save.

2) Click on project menu and rebuild all target files.

3) In build window, it should report as ‘0 Error(s), 0 Warning(s)’.

4) Click on debug menu and select start/stop debug session.

5) Click on peripherals, select I/O ports like as port 1.

6) A new window will pop up, which represents the port and pins.

Fig: parallel port

7) Now to execute the program stepwise click on F10 key.

8) To exit out click on debug menu and select start/stop debug session.

PROLOAD V4.1

Burn the hex file to microcontroller using the Proload V4.1 software.

Steps:

1. Connect the burner to PC using serial communication port

2. Browse the hex file .

3. Now burn the hex file to microcontroller using send command.

C PROGRAM FILE

#include<reg51.h>

#include<delay.h>

# define DATA P1

sbit e=P3^7;

sbit rw=P3^6;

sbit rs=P3^5;

sbit s1=P2^0;

sbit s2=P2^1;

sbit s3=P2^2;

sbit relay=P0^6;

sbit s4=P2^3;

void mov_stepper(unsigned char dir,unsigned char rot)

{

while(rot>0)

{ if(dir=='c')

{

P0=0X08;

ms_delay(5);

P0=0X04;

ms_delay(5);

P0=0X02;

ms_delay(5);

P0=0X01;

ms_delay(5);

}

if(dir=='a')

{

P0=0X01;

ms_delay(5);

P0=0X02;

ms_delay(5);

P0=0X04;

ms_delay(5);

P0=0X08;

ms_delay(5);

}

rot--;

}

}

void lcd_cmd(unsigned char temp)

{

DATA=temp;

rs=0;

rw=0;

e=1;

ms_delay(5);

e=0;

ms_delay(5);

}

void lcd_data(unsigned char temp)

{

DATA=temp;

rs=1;

rw=0;

e=1;

ms_delay(5);

e=0;

ms_delay(5);

}

void lcd_init()

{

lcd_cmd(0x38);

lcd_cmd(0x06);

lcd_cmd(0x0e);

lcd_cmd(0x01);

lcd_cmd(0x80);

}

void lcd_puts(unsigned char *s)

{ lcd_init();

while(*s!='\0')

{

lcd_data(*s);

s++;

}

}

void main()

{

P0=0X00;

P2=0X00;

while(1)

{

if(s1==1)

{

mov_stepper('c',3);

lcd_puts("FIELD A");

while(s1!=0)

{

relay=1;

}

relay=0;

mov_stepper('a',3);

lcd_puts("MONITORING");

}

if(s2==1)

{

mov_stepper('c',6);

lcd_puts("FIELD B");

while(s2!=0)

{

relay=1;

}

relay=0;

mov_stepper('a',6);

lcd_puts("MONITORING");

}

if(s3==1)

{

mov_stepper('a',9);

lcd_puts("FIELD C");

while(s3!=0)

{

relay=1;

}

relay=0;

mov_stepper('c',9);

lcd_puts("MONITORING");

}

if(s4==1)

{

lcd_puts("FIELD D");

while(s4!=0)

{

relay=1;

}

relay=0;

lcd_puts("MONITORING");

}

lcd_puts("MONITORING");

}

}

APPLICATIONS

1.IRRIGATION IN FIELDS.

2.IRRIGATION IN GARDENS,PARKS.

3.VERY EFFICIENT FOR PADDY(RICE) FIELDS.

4.PICSICULTURE.

REFERENCES

Muhammad Ali Mazidi , “The 8051 Microcontroller & Embedded Systems ” .

EXTENTIONS IN THE PROJECT

The working of above project is basically dependent on the output of the humidity sensors. Whenever there is

need of excess water in the desired field(RICE crops) then it will not be possible by using sensor technology. For

this we will have to adopt the DTMF technology. By using this we will be able to irrigate the desired field & in

desired amount.

This technology will be implemented in this project in the next (8th ) semester . this will be our extention to the

project for the the next semester.