Raja Sekar An

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DESIGN AND PERFORMANCE ANALYSIS OF

WATE PUMPING USING SOLAR PV

A PROJECT REPORT

Submitted by

1. RAJASEKARAN.E (44109105008)

2. THIRUMALAI.E (44109105015)

3. PARTHIBAN.E (44109105307)

4. VENKATESAN.D (44109105313)

In partial fulfillment for the award of the degree

Of

BACHELOR OF ENGINEERING

IN

ELECTRICAL AND ELECTRONICS ENGINEERING

SRI ARAVINDAR ENGINEERING COLLEGE

SEDARAPET

ANNA UNIVERSITY :: CHENNAI 600 025

APRIL 2013


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ANNA UNIVERSITY :: CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report DESIGN AND PERFORMANCE

ANALYSIS OF WATER PUMPING USING SOLAR PV is the

bonafide work of RAJASEKARAN.E (44109105008), THIRUMALAI.E

(44109105015) , PARTHIBAN.E (44109105307), VENKATESAN.D

(44109105313) who carried out the project work under my supervision.

SIGNATURE SIGNATURE

Mr. R.VENKADESH Mr. M . RAJKUMAR

HEAD OF THE DEPARTMENT SUPERVISOR

Lecturer Lecturer

Electrical And Electronics Engineering Electrical And Electronics Engineering

Sri Aravindar Engineering College Sri Aravindar Engineering College

Sedarapet 605 111 Sedarapet 605 111

Submitted for the project work and viva-voce held on ..

INTERNAL EXAMINER EXTERNAL EXAMINER


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ACKNOWLEDGEMENT

First and foremost i thank ALMIGHTY for showering his abundant and

gracious blessings for the completion of the project successfully heartfelt

thanks to our respected Chairman MR. S.NITIYANANDAN for granting

permission and giving inspiration for completion of the project work.

My faithful thanks to our Principal Dr. S.RAJARAJAN for the

motivation in studies and completion of the project.

With my heart full pleasure to thank our Head Of The Department

Mr. R.VENKADESH for his thought suggestions regarding the project and

my thanks to project Co-Ordinator Ms. T.PREMA Lecturer in Department Of

Electrical And Electronics Engineering.

We alone express our sincere thanks to the internal project Guide

Mr. .RAJKUMAR for his kind help constant encouragement and his

technical advice then and there.

I also extend my thanks to all our staff members in Department Of

Electrical And Electronics Engineering for the completion of the project

successfully.

I express my sincere gratitude to the management for providing the

excellent library, computing and other facilities for my completion of the

project .

Last but not least i like to express my sincere thanks to my beloved

Parent and friends for their constant love and support that gave their considerable

assistance in shaping out this project successfully alone.


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ABSTRACT

This paper deals with the design and performance analysis of a DC

photovoltaic water pumping system. A DC solar water pump is built and

experimented to observe the results with a direct connection from solar array.

Various methodologies to increase the efficiency of the system have been

discussed to implement in the system. Finally DC-DC buck converter is designed

and constructed to provide current boosting to the DC pump for having a better

performance from the system. All components in the system are procured from

locally available markets which eventually decrease the overall cost. The designed

DC water pumping system has a great prospect to solve out the energy crisis in the

irrigation season as well as it can be used to cultivate lands throughout the year.

In this paper, a simple but efficient photovoltaic water pumping system is

presented. It provides the operation of a DC solar water pump in both the direct-

coupled method and the pump controller connected method. A pump-controller

with the help of Buck converter design is constructed and finally implemented

into the system to increase the overall efficiency of pumping system.Solar

photovoltaic pumping offers a way out to the people from the energy crisis.

Numerous technological challenges were overcome through engineering solutions

and finally a representative model of system is built which can be implemented in

the field. Upfront cost of the solar pumping system potentially hinder to popularize

the system in the rural areas but private companies, bank and govt. Can come

forward for a solution that can fit to rural people.


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CHAPTER 1

INTRODUCTION

Energy crisis is the most important issue in todays world. Availability of

Power supply is one of the most important factors for a countrys economic

growth. Energy, water and agriculture together form a formidable synergy, which

when appropriately utilized and managed, can drive any nation way forward.

Despite being blessed with a fertile soil for agriculture, Indias food and

agricultural products production is so low due to the gaps between the strong

demand of energy and supply of energy. Applying solar photovoltaic panels for

irrigation can change the scenario of the country.

1.1 EXISTING SYSTEM:

At present there is no system in existence which uses solar power in

irrigation procedure. In the existing system the motor pump is made to run using

available AC power. This increases power consumption which is the maindisadvantage.

1.2 SCOPE OF THE PROJECT:

In this project aims at, the solar power is used to run the pump motor. The

solar power is stored in a battery and the power stored is used to run the DC Pump

Motor. The voltage and current taken by the Pump Motor is measured andmonitored using the PIC Microcontroller.

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1.3 LITERATURE SURVEY:

TITLE 1: PERFORMANCE OF MINOR IRRIGATION IN KRISHNA

BASIN OF KARNATAKA-AN ECONOMIC PERSPECTIVE:

ABSTRACT :

Water, the most precious natural resource covers almost three-fourths of

earths Surface. Its abundance as well as scarcity has been greatly instrumental in

shaping the lifestyle and culture of the people inhabiting the earth.Early

civilizations developed and flourished on the shores of major rivers like Tigris and

the Eupharates in Mesopotamia, the Nile in Egypt, the Huang-Ho in China andIndus valley in India. For all types of agriculture such as geoponic, aeroponic and

hydroponic water is a basic component.

TITLE 2: PERFORMANCE ENHANCEMENT OF PV SOLAR SYSTEM

BY DIFFUSED REFLECTION:

ABSTRACT :

Various methods are being adopted to enhance the performance of a solar

panel. The most common method is to track the sun for performance enhancement.

Such method needs complicated control and drive circuits for implementation.

Also, the power required for the tracking motor has to be provided by the solar

panel and the battery system. Although better performance is achievable by the sun

tracker, higher cost and frequent maintenance are required. In this paper,

performance enhancement of solar panels has been experimented utilizing diffused

reflectors.

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Application of diffused reflectors is cheap, simple and does not require any

additional equipments or devices. Simple white reflectors can be used to optimize

the performance of the solar panel. Experimental results indicate appreciable

enhancement in the overall output of the solar panel. For comparative study,

experimental readings were simultaneously taken with i) sun tracking, ii)

the panel aligned at 23.50 with the horizontal using diffused reflectors and iii) the

panel aligned at 23.50 with the horizontal without diffused reflectors. Comparative

results depicted for different conditions show encouraging enhancement of the

performance of the solar panel.

TITLE 3:ANNUAL ACTIVITIES REPORT:

ABSTRACT:

With the change in priorities and imperatives of development functions of

the State, Planning & Co-ordination Department has emerged as one of the major

nodal departments of Government. This Department plays a vital role in evolving

Effective and sustainable short term and long term strategies for overall

development of the State. This Department prepares policy framework for

development and is also responsible for co-ordinating the efforts of different

Development Departments. Keeping in view the needs and aspirations of the

people and within the broad framework of the long term development strategies

and priorities envisaged for the State, the Department formulates Annual and Five

Year Plans in accordance with the guidelines of the Planning Commission and as

per the directions received from the Government.

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CHAPTER2

NUMBER OF UNITS

The Number Of Units Are Given By,

1. Power supply unit

2. Microcontroller Unit

3. Sensor Unit

4. Device Driver Unit

5. Display Unit

6. Software Unit

2.1 POWER SUPPLY UNIT:

The supply of 5V DC given to the system, which is converting from

230V AC supply. Firstly, the step down transformer used here is for converting the

230V AC into 12V AC. The microcontroller will support only the DC supply, so

the AC supply is converted to DC using the bridge rectifier. The output of the

rectifier will have ripples so we are using the 2200uf capacitor for filtering those

ripples.

The output from the filter is given to the 7805 voltage regulator, which will

convert the 12V DC into 5V DC. The output from the regulator will be filtered

using the 1000uf capacitor, so the pure 5V DC is getting as the output from the

power supply unit. Here we are using the PIC microcontroller, which will be

capable of getting the supply of 5V DC so we have to convert the 230V AC supply

into 5V DC supply.

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2.2 MICROCONTROLLER UNIT:

2.2.1 Pic 16f877a Microcontroller

Here the PIC microcontroller is interfaced with current, voltagesensors and solar panel. The sensors are connected to inbuilt analog to

digital converter pins of PIC microcontroller. The voltage from the solar

panel is given to drive the pump motor and the voltage and current

consumption of the pump motor is calculated. The microcontroller is the

heart of the overall system.

2.3 SENSOR UNIT:

2.3.1 Voltage Sensor

The voltage sensor is used to measure the voltage consumed by the

pump motor. The output of the sensor is given to the ADC which in turn is

given to microcontrollers input for further processing.

2.3.2 Current Sensor

The current sensor is used to measure the amount of current consumed

by the pump motor and is fed to the microcontroller for further processing.

2.4 DEVICE DRIVER UNIT :

2.4.1 Relay Driving

It nothing but a simple relay driver circuit it is used to connect anddisconnect the load and solar panel.

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2.4.2 ULN2003

The induction motors will be controlled by using the driving circuit in whichthe ULN2003 driver IC will be used to provide the proper current rating to

the motor. The sinking current of the ULN driver is around 500ma.

2.5 DISPLAY UNIT:

2.5.1 LCD

A liquid crystal display (LCD) is a flat panel display, electronic visual

display, or video display that uses the light modulating properties of liquid

crystals (LCs). LCDs do not emit light directly. The status of the system like

the voltage and current is displayed through the LCD.

2.6 SOFTWARE UNIT:

Software is used to compile the coding of the desired application for the

corresponding embedded system.

2.6.1 MPLAB (or ) CCS Compiler

The PIC16F877A microcontroller is founded by Microchip and they

had designed a compiler to develop user-defined programs for different kind of

applications which is namely called as MPLAB Compiler.Both Assembly and C

programming languages can be used with MPLAB IDE v8. It is also a cross

compiler which can also be used other kind of architectures. For PIC series of

controllers only MPLAB compiler is used. In this project we are using

PIC16F877A Microcontroller and for that controller Microchip developed a

compatible and user-friendly compiler for programming which is named

MPLAB or hi-tech compiler. Hence we choose that controller.

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CHAPTER3

BLOCK DIAGRAM OF WATER PUMPING

3.1 BLOCK DIAGRAM

Fig 3.1 Block Diagram Of Water Pumping

3.2 GIVEN INPUT AND EXPECTED OUTPUT

3.2.1 POWER SUPPLY UNIT:

In the power supply unit the 230V AC is converted into 5V DC.

Given Input:

230V AC supply is given as the input to the power supply unit.

7

Battery & Power

Su l

PIC

16F877A

Micro

Controller

LCD

Driver Circuit12V Solar

Panel

Pump

Motor Voltage Sensor

Current Sensor


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Expected Output:

The 5V DC supply is getting as the output from the power supply unit.

3.2.2 MICROCONTROLLER UNIT:

Given input

The sensor is the input of the microcontroller.

Expected output

The sensor senses means the output voltage given to the microcontroller.

3.2.3 SENSOR UNIT:

Voltage Sensor:Given input

The voltage is the input to the sensor.

Expected output

The output value given to the microcontroller.

Current Sensor:Given input

The current value is the input to the sensor.

Expected output

The output value given to the microcontroller.

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3.2.4 DISPLAY UNIT :

LCD:Given input

The microcontroller gives input to the lcd module.

Expected output

The operations are displayed in Lcd.

3.2.5 DRIVER CIRCUIT UNIT:

Relay driver:Given input

The trigger is given from microcontroller.

Expected output

Based on the trigger input the motor will run.

Pump motor:Given input

The relay output is given to the pump motor.

Expected output

Based on the output voltage the motor will run.

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CHAPTER 4

CIRCUIT DIGRAM

BLOCK DIAGRAM DESCRIPTION

Block 1: PIC16F877A Microcontroller with Power Supply

Block 2: 12V,1.2A Battery


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CHAPTER 5

5. BLOCK DIAGRAM DESCRIPTION

Block 1: PIC16F877A Microcontroller with Power Supply

Block 2: 12V,1.2A Battery

Block 3: 12V Solar Panel

Block 4: LCD

Block 3: 12V Solar Panel

Block 4: LCD

Block 5: Current Sensor

Block 6: Voltage Sensor

5.1 BLOCK 1: PIC16F877A MICROCONTROLLER WITH POWER

SUPPLY

The ac voltage, typically 220V rms, is connected to a transformer, which steps

that ac voltage down to the level of the desired dc output. A diode rectifier then

provides a full-wave rectified voltage that is initially filtered by a simple capacitor

filter to produce a dc voltage. This resulting dc voltage usually has some ripple or

ac voltage variation.

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A regulator circuit removes the ripples and also remains the same dc value

even if the input dc voltage varies, or the load connected to the output dc voltage

changes. This voltage regulation is usually obtained using one of the popular

voltage regulator IC units.

Fig 5.1 Block Diagram of Power supply

5.1.1 WORKING PRINCIPLE

TRANSFORMER :The potential transformer will step down the power supply voltage (0-230V) to

(0-6V) level. Then the secondary of the potential transformer will be connected to

the precision rectifier, which is constructed with the help of opamp. The

advantages of using precision rectifier are it will give peak voltage output as DC,

rest of the circuits will give only RMS output.

BRIDGE RECTIFIER:When four diodes are connected as shown in figure, the circuit is called as

bridge rectifier. The input to the circuit is applied to the diagonally opposite

corners of the network, and the output is taken from the remaining two corners.

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TRANSFORMER RECTIFIER FILTER IC REGULATOR LOAD


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Let us assume that the transformer is working properly and there is a

positive potential, at point A and a negative potential at point B. the positive

potential at point A will forward bias D3 and reverse bias D4. The negative

potential at point B will forward bias D1 and reverse D2. At this time D3 and D1

are forward biased and will allow current flow to pass through them; D4 and D2

are reverse biased and will block current flow.

The path for current flow is from point B through D1, up through RL,

through D3, through the secondary of the transformer back to point B. this path is

indicated by the solid arrows. Waveforms (1) and (2) can be observed across D1

and D3.One-half cycle later the polarity across the secondary of the transformer

reverse, forward biasing D2 and D4 and reverse biasing D1 and D3.

Current flow will now be from point A through D4, up through RL, through

D2, through the secondary of T1, and back to point A. This path is indicated by the

broken arrows. Waveforms (3) and (4) can be observed across D2 and D4. The

current flow through RL is always in the same direction. In flowing through RL

this current develops a voltage corresponding to that shown waveform (5).

Since current flows through the load (RL) during both half cycles of the applied

voltage, this bridge rectifier is a full-wave rectifier.

The peak voltage developed between points X and y is 1000 volts in

bothcircuits. In the conventional full-wave circuit shownin view A, the peak

voltage from the center tap to either X or Y is 500 volts. Since only one diode can

conduct at any instant, the maximum voltage that can be rectified at any instant is

500 volts.

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The maximum voltage that appears across the load resistor is nearly-but

never exceeds-500 v0lts, as result of the small voltage drop across the diode. In the

bridge rectifier shown in view B, the maximum voltage that can be rectified is the

full secondary voltage, which is 1000 volts. Therefore, the peak output voltage

across the load resistor is nearly 1000 volts.

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. The regulators can be selected for operation

with load currents from hundreds of milli amperes to tens of amperes,

corresponding to power ratings from milli watts to tens of watts.

Fig 5.1.1 Circuit Diagram Of Power Supply

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A fixed three-terminal voltage regulator has an unregulated dc input voltage,

Vi, applied to one input terminal, a regulated dc output voltage, Vo, from a second

terminal, with the third terminal connected to ground. The series 78 regulators

provide fixed positive regulated voltages from 5 to 24 volts. Similarly, the series

79 regulators provide fixed negative regulated voltages from 5 to 24 volts.

For ICs, microcontroller, LCD --------- 5 volts For alarm circuit, op-amp, relay circuits ---------- 12 volts

PIC 16F877A MICROCONTROLLER:This section describes how to generate +5V DC power supply. The power

supply section is the important one. It should deliver constant output regulated

power supply for successful working of the project. A 0-12V/1 mA transformer

used for this purpose. The primary of this transformer is connected in to main

supply through on/off switch& fuse for protecting from overload and short circuit

protection. The secondary is connected to the diodes to convert 12V AC to 12V

DC voltage. And filtered by the capacitors, Which is further regulated to +5v, by

using IC 7805.

Introduction Of Pic16f877aIt features 200 ns instruction execution, 256 bytes of EEPROM data

memory, self programming, an ICD, 2 Comparators, 8 channels of 10-bit Analog-

to-Digital (A/D) converter, 2 capture/compare/PWM functions, a synchronous

serial port that can be configured as either 3-wire SPI or 2-wire I2C bus, a USART,

and a Parallel Slave Port.

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5.1.2 MICROCHIP PIC16F877A FEATURES:

High-Performance Risc Cpu Operating speed: 20 MHz, 200 ns instruction cycle Operating voltage: 4.0-5.5V Industrial temperature range (-40 to +85C) 15 Interrupt Sources 35 single-word instructions All single-cycle instructions except for program branches (two-cycle)

Special Microcontroller Features Flash Memory: 14.3 Kbytes (8192 words) Data SRAM: 368 bytes Data EEPROM: 256 bytes Self-reprogrammable under software control In-Circuit Serial Programming via two pins (5V) Power-saving Sleep mode Selectable oscillator options In-Circuit Debug via two pins

Peripheral Features 33 I/O pins; 5 I/O ports Timer0: 8-bit timer/counter with 8-bit prescaler Timer1: 16-bit timer/counter with prescaler

o Can be incremented during Sleep via external crystal/clock

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Timer2: 8-bit timer/counter with 8-bit period register, prescaler andpostscaler

Two Capture, Compare, PWM moduleso 16-bit Capture input; max resolution 12.5 nso 16-bit Compare; max resolution 200 nso 10-bit PWM

Synchronous Serial Port with two modes:o SPI Mastero I2C Master and Slave

USART/SCI with 9-bit address detection Parallel Slave Port (PSP)

o 8 bits wide with external RD, WR and CS controls Brown-out detection circuitry for Brown-Out Reset

Analog Features 10-bit, 8-channel A/D Converter Brown-Out Reset Analog Comparator module

o 2 analog comparatorso Programmable on-chip voltage reference moduleo Programmable input multiplexing from device inputs and internal

VREF

o Comparator outputs are externally accessible

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5.1.3 PIN DIAGRAM:

Fig.5.1.3 Pin Diagram

5.1.4 TYPES OF MEMORIES FOR PIC16F877A

1.Program Memory- A memory that contains the program (which we hadwritten), after we've burned it. As a reminder, Program Counter executes

commands stored in the program memory, one after the other.

2. Data MemoryThis is RAM memory type, which contains a specialregisters like Special Faction Register and General Purpose Register.

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These two memories have separated data buses, which makes the access to each

one of them very easy.

3. Data EEPROM (Electrically Erasable Programmable Read-OnlyMemory) - A memory that allows storing the variables as a result of

burning the written program.

Each one of them has a different role. Program Memory and Data Memory

two memories that are needed to build a program, and Data EEPROM is use to

save data after the microcontroller is turn off. Program Memory and Data

EEPROM they are non-volatile memories, which store the information even afterthe power is turn off. These memories called Flash Or EEPROM. In contrast, Data

Memory does not save the information because it needs power in order to maintain

the information stored in the chip.

1. PIC16F87XA Program Memory:

The PIC16F87XA devices have a 13-bit program counter capable of

addressing an 8K word x 14 bit program memory space. This memory is used to

store the program after we burn it to the microcontroller. The PIC16F876A/877A

devices have 8K words x 14 bits of Flash program memory that can be electrically

erased and reprogrammed. Each time we burn program into the micro, we erase an

old program and write a new one.

Program Memory is divided into the pages, where the program is stored.Data Memory is divided into the banks. The banks are located inside the RAM,

where the special registers and the data located.

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Fig.5.1.4 a) V Pic16f87xa Program Memory:

2. PIC16F87XA Data Memory :

The data memory is partitioned into multiple banks which contain the

General Purpose Registers and the Special Function Registers. Number of banks

may vary depending on the microcontroller. The lower locations of each bank are

reserved for the Special Function Registers.

Above the Special Function Registers are General Purpose Registers,

implemented as static RAM. While program is being executed, it is working with

the particular bank. The default bank is BANK0.

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Fig.5.1.4 b) PIC16F87XA Data Memory

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PIC16F876A/877A Register File MapIn order to start programming and build automated system, there is no need

to study all the registers of the memory map, but only a few most important ones:

STATUS registerchanges/moves from/between the banks PORT registersassigns logic values (0/1) to the ports TRIS registers - data direction register (input/output)

You can learn about other registers at a later stage or as needed.

a) STATUS register:In most cases, this register is used to switch between the banks (Register

Bank Select), but also has other capabilities.

PIC STATUS registerWith the help of three left bits (IRP, RP1, and RP0) one can control the

transition between the banks:

IRP - Register Bank Select bit, used for indirect addressing method. RP1:RP0: - Register Bank Select bits, used for direct addressing method.

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To distinguish between the two methods, at this point, the will use the

definition of fundamental concepts. Later on, the two methods will be studied in

detail. When the IRP Equal to 0, the program will work with banks 0,1.

When the IRP Equal to 1, the program will work with banks 2, 3.

The following table demonstrates, which of the Banks the program is

working with, based on the selection of the RP0 and RP1 bits:

RP1:RP0 BANK

00 0

01 1

10 2

11 3

Table 5.14 Selection Of The RP0 And RP1 Bits

An example of using STATUS register and Register Bank Select bit:

1.bsf STATUS, 5 ; Change to Bank 12. clrf TRISB ; Set PORTB as output3.bcf STATUS, 5 ; Change to Bank 0

In the first line, we are in changing/setting the 5th bit, RP0, in the STATUS

register to 1, and thus, base on the table we are switching/selecting Bank 1.

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After Port B was set as output in the second line, we switched back to Bank 0 by in

changing/setting the 5th bit, RP0, in the STATUS register to 0, in the third line.

C: Carry/borrow bit (ADDWF, ADDLW, SUBLW,SUBWF instructions)

1 = A carry-out from the Most Significant bit of the result occurred

0 = No carry-out from the Most Significant bit of the result occurred

An example of using STATUS register and Carry/borrow bit:

1. Movlw 2002. Addwf 100, 0

In this example, we are assigning value of 200 to the W (working)

register. Then, we are adding the value of 100 and the W register together. The

result is stored in W register and should be 300 (200+100).

However, the maximum value is 256, resulting in carry out. The C (bit 0) of the

STATUS register becomes 1 (C = 1). Register W will contain the reminder: 44.

DC: Digit carry/borrow bit (ADDWF, ADDLW,SUBLW,SUBWF

instructions) (for borrow, the polarity is reversed)

1 = A carry-out from the 4th low order bit of the result occurred

0 = No carry-out from the 4th low order bit of the result.

Z: Zero bit

1 = The result of an arithmetic or logic operation is zero

0 = The result of an arithmetic or logic operation is not zero

The bits 3 and 4 are used with WDT - Watchdog Timer.

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PD: Power-down bit

1 = After power-up or by the CLRWDT instruction

0 = By execution of the SLEEP instruction

TO: Time-out bit

1 = After power-up, CLRWDT instruction or SLEEP instruction

0 = A WDT time-out occurred

b)PORT register:The role of the PORT register is to receive the information from an external

source (e.g. sensor) or to send information to the external elements (e.g. LCD). The

28-pin devices have 3 I/O ports, while the 40/44-pin devices, like PIC16F877, have

5 I/O ports located in the BANK 0.

1.PORTA is a 6-bit wide, bidirectional port. The corresponding datadirection register is TRISA.Setting a TRISA bit (= 1) will make the

corresponding PORTA pin an input. Clearing a TRISA bit (= 0) will

make the corresponding PORTA pin an output.

2.PORTB is an 8-bit wide, bidirectional port. The corresponding datadirection register is TRISB. Setting a TRISB bit (= 1) will make the

corresponding PORTB pin an input. Clearing a TRISB bit (= 0) will

make the corresponding PORTB pin an output.

3.PORTC is an 8-bit wide, bidirectional port. The corresponding datadirection register is TRISC. Setting a TRISC bit (= 1) will make the

corresponding PORTC pin an input.

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Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output.

4. PORTD is an 8-bit port with Schmitt Trigger input buffers. Each pin is

individually configurable as an input or output.

5. PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6 and RE2/CS/AN7)

which are individually configurable as inputs or outputs. These pins have

Schmitt Trigger input buffers.

We can control each port by using an assigned address of specific port, but

there is much easier way to control the port. We are allowed to use the names of

the ports without considering their addresses.

For example:

# define SWITCH PORTA, 0

We define a variable named SWITCH, which received a value of bit number

0 of the PORTA. Usually we define the ports at the beginning of the program, and

then we use only the given names.

c) TRIS register:The TRIS register is data direction register which defines if the specific bit

or whole port will be an input or an output. Each PORT has its own TRIS register.

Here's a map of the locations:

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BANK0 BANK1

PORTA TRISA

PORTB TRISB

PORTC TRISC

PORTD TRISD

PORTE TRISE

The default mode of each TRIS is input. If you want to set a specific

port as exit you must change the state of the TRIS to 0. Keep in mind: to change a

specific port to an output, one should first move to the BANK1, make the change,

and then return to BANK0. The default state of the banks is BANK0.

The running program is working only with one bank at all time. If not set

otherwise, then as stated, the default bank is BANK0. Part of the registers located

inside BANK0, and some are not. When we need to access a register that is not

located inside BANK0, we are required to switch between the banks.

3. PIC16F87XA Data EEPROM:

The data EEPROM and Flash program memory is readable and writable

during normal operation (over the full VDD range). This memory is not directlymapped in the register file space. Instead, it is indirectly addressed through the

Special Function Registers.

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There are six SFRs used to read and write to this memory:

1. EECON12. EECON23. EEDATA4. EEDATH5. EEADR6. EEADRH

When interfacing to the data memory block, EEDATA holds the 8-bit data for

read/write and EEADR holds the address of the EEPROM location being accessed.

These devices have 128 or 256 bytes of data EEPROM (depending on the device),

with an address range from 00h to FFh. On devices with 128 bytes, addresses from

80h to FFh are unimplemented.

A few important points about Data EEPROM memory:

It lets you save data DURING programming The data is saved during the burning process You can read the data memory during the programming and use it The use is made possible with the help of SFR

At this point there is no need to learn how to use this memory with special

registers, because there are functions (writing and reading) that are ready.

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5.1.5 PIC TIMER :

Many times, we plan and build systems that perform various processes that

depend on time.Simple example of this process is the digital wrist watch. The role

of this electronic system is to display time in a very precise manner and change the

display every second (for seconds), every minute (for minutes) and so on. To

perform the steps we've listed, the system must use a timer, which needs to be very

accurate in order to take necessary actions.

The clock is actually a core of any electronic system. In this PIC timer

module tutorial we will study the existing PIC timer modules. The microcontrollerPIC16F877 has 3 different timers:

PIC Timer0 PIC Timer1 PIC Timer2

We can use these timers for various important purposes. So far we used

delay procedure to implement some delay in the program, that was counting up

to a specific value, before the program could be continued.

"Delay procedure" had two disadvantages:

we could not say exactly how long the Delay procedure was in progress we could not perform any further steps while the program executes the

"delay procedure"

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Now, using Timers we can build a very precise time delays which will be

based on the system clock and allow us to achieve our desired time delay well-

known in advance. In order for us to know how to work with these timers, we need

to learn some things about each one of them. We will study each one separately.

1.PIC Timer0 :

The Timer0 module timer/counter has the following features:

8-bit timer/counter Readable and writable 8-bit software programmable prescaler Internal (4 Mhz) or external clock select Edge select (rising or falling) for external clock

Lets explain the features of PIC Timer0 we have listed above:

Timer0 has a register called TMR0 Register, which is 8 bits of size.

We can write the desired value into the register which will be increment as the

program progresses. Frequency varies depending on the Prescaler. Maximum

value that can be assigned to this register is 255.

TMR0IF - TMR0 Overflow Interrupt Flag bit.

The TMR0 interrupt is generated when the TMR0 register overflows from FFh to

00h. This overflow sets bit TMR0IF (INTCON). You can initialize the value of

this register to whatever you want (not necessarily "0").

We can read the value of the register TMR0 and write into.

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We can reset its value at any given moment (write) or we can check if there is

a certain numeric value that we need (read).

Prescaler - Frequency divider:

1:2 1:4 1:8 1:16 1:32 1:64 1:128 1:256

The structure of the OPTION_REG register:We perform all the necessary settings with OPTION_REG Register. The size of

the register is 8 bits.

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Initializing the OPTION_REG register:The following is an example how we can initialize the OPTION_REG:

1. PSA=0; // Prescaler is assigned to the Timer0 module2. PS0=1; // Prescaler rate bits3. PS1=1; // are set to 1114. PS2=1; // which means divide by 2565. TOSE=0; // rising edge

clock diagram of the PIC Timer0 / WDT prescaler :

Fig.5.1.5 a) PIC Timer0 Block Diagram

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Calculating Count, Fout, and TMR0 values:If using INTERNAL crystal as clock, the division is performed as follow:

PIC TIMER0 formula for internal clock

Fout Output frequency after the division.

Tout The Cycle Time after the division.

4 - The division of the original clock (4 MHz) by 4, when using internal crystal as

clock (and not external oscillator).

Count- A numeric value to be placed to obtain the desired output frequency - Fout.

(256 - TMR0) - The number of times in the timer will count based on the register

TMR0.

1. An example of INTERNAL crystal as clock :

Suppose we want to create a delay of 0.5 second in our program using

Timer0. What is the value of Count?

Calculation:

First, lets assume that the frequency division by the Prescaler will be 1:256.

Second, lets set TMR0=0.

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Thus:

Formula to calculate Cout using Timer0

If using EXTERNAL clock source (oscillator), the division is performed as follow:

PIC TIMER0 formula for external clock

In this case there is no division by 4 of the original clock. We use the external

frequency as it is.

2. An example of EXTERNAL clock source (oscillator):

What is the output frequency - Fout, when the external oscillator is 100kHz

and Count=8?

Calculation:

First, lets assume that the frequency division by the Prescaler will be 1:256.

Second, lets set TMR0=0. Thus:

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Formula to calculate Fout for Timer0

2. PIC Timer1:

The Timer1 module, timer/counter, has the following features:

16-bit timer/counter consisting of two 8-bit registers (TMR1H and TMR1L) readable and writable 8-bit software programmable prescaler Internal (4 Mhz) or external clock select Interrupt on overflow from FFFFh to 0000h

Lets explain the features of PIC Timer1 we have listed above:

Timer1 has a register called TMR1 register, which is 16 bits of size.

Actually, the TMR1 consists of two 8-bits registers:

TMR1H TMR1L

It increments from 0000h to the maximum value of 0xFFFFh (or 0 b1111

1111 1111 1111 or 65,535 decimal). The TMR1 interrupt, if enabled, is generated

on overflow which is latched in interrupt flag bit, TMR1IF (PIR1).

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This interrupt can be enabled/disabled by setting/clearing TMR1 interrupt

enable bit, TMR1IE (PIE1). You can initialize the value of this register to

whatever you want (not necessarily "0").

TMR1IFTMR1 overflow Interrupt Flag bit.

This flag marks the end of ONE cycle count. The flag need to be reset in the

software if you want to do another cycle count. We can read the value of the

register TMR1 and write into. We can reset its value at any given moment (write)

or we can check if there is a certain numeric value that we need (read).

PrescalerFrequency divider:

We can use Prescaler for further division of the system clock. The size of the

register is 2-bit only, so you can make four different division. The options are:

1:1 1:2 1:4 1:8

You can choose whether to use an internal system clock (crystal) or external

oscillator that can be connected to a pin RC0.

The structure of the T1CON register:We perform all the necessary settings with T1CON register. As we can see,

the size of the register is 8 bits. Lets explore the relevant bits:

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Initializing the T1CON register:The following is an example how we can initialize the T1CON register:

1. TMR1ON=1; // the timer is enable2. TMR1CS=0; // internal clock source3.

T1CKPS0=0; // Prescaler value set to 00

4. T1CKPS1=0; // which means 1:1 (no division)Or you can set all the T1CON register at once as follows:

T1CON=0b00000001;

Block diagram of the PIC Timer1

Fig 5.1.5 b) PIC TIMER1 Block Diagram

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Calculating Count, Fout, and Timer1 values:

If using INTERNAL crystal as clock, the division is performed as follow:

PIC TIMER1 formula for internal clock

FoutThe output frequency after the division.




Count- A numeric value to be placed to obtain the desired output frequency - Fout.

(256 - TMR1) - The number of times in the timer will count based on the register

TMR0.

If using EXTERNAL clock source (oscillator), the division is performed

as follow:

PIC TIMER1 formula for external clock

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Simple example and calculation of how to use TIMER1:

Suppose we want to create a delay of 2 second in the our program using

Timer1. What is the value of Count?

Calculation:

First, lets assume that the frequency division by the Prescaler will be 1:1. Second,

lets set TMR1=0, which means the TMR1 will count 65,536 times. Thus:

Formula to calculate Cout for Timer1

3. PIC Timer2:

The Timer2 Module Has The Following Features:

Two 8-Bit Registers ( TMR2 And PR2 )

Readable And Writable

Prescaler And A Postscaler

Connected Only To An Internal Clock - 4Mhz Crystal

Interrupt On Overflow

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TIMER 2 Prescaler and Postscaler :

Fig 5.1.5 c) TIMER 2 Prescaler And Postscaler

TMR2IF - TMR2 to PR2 Match Interrupt Flag bit.

Comparator compares the value of the register tmr2 and the maximum value of

the register pr2.

Tmr2 the register in which the initial count value is written. Pr2 the register in which the final or the maximum count value is

written.

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TIMER 2 BLOCK DIAGRAM:

Fig 5.1.5 d) Timer2 Block Diagram

How to calculate the required values of the TIMER2:

Fout The output frequency after the division.




Count- A numeric value to be placed to obtain the desired output frequency - fout.

(PR2TMR2) - The number of times the counter will count.

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Simple example and calculation of how to use TIMER2:

Suppose we want to create a delay of 1 second in the our program using Timer2.

What is the value of Count?

Calculation:

First, lets assume that the frequency division by the Prescaler will be 1:1 and

Postscaler will be 1:16. Second, lets set TMR1=0 and PR2=255. Thus:

5.1.6 INTRODUCTION TO SERIAL COMMUNICATION WITH

PIC16F877 MICROCONTROLLER:

In this tutorial we will study the communication component USART

(Universal Synchronous Asynchronous Receiver Transmitter) located within the

PIC. It is a universal communication component (Synchronous/Asynchronous),

which can be used as transmitter or as receiver. We will look at:

serial and parallel communications synchronous and asynchronous communications

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how to enable serial communication - TXSTA and RCSTA registers An example of 8-bit transmission An example of 9-bit transmission how to calculate the value being placed in the SPBRG register USART Transmit and Receive block diagrams Max323 Driver/Receiver the implementation of the PIC serial communication (C program and a

video)

We will show how to set USART in order to allow communication between

PIC to PIC or between PIC to a personal computer. We will start with the

definition of media concepts. There are two options to differentiate when speaking

about transmission of information on the transmission lines:

serial communication parallel communication

In order to understand what serial communication is, and emphasize the

difference between serial communication and parallel communication, lets take a

look at the following example: We have a multi-bit word, and we want to transmit

it from one computer to the second computer.

1.Using the serial communication:

When using the serial communication we transmit the multi-bit word bitafter bit (when at any given moment only one bit will pass).

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Fig.5.1.6a) Transmitting the word 10011101 using serial communication.

2. Using the parallel communication:When using the parallel communication, however, the number of bits will

be transmitted at once from one computer to the second computer.

Fig.5.1.6b)Transmitting the word 10011101 sing parallel communication.

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In addition to the serial and parallel communications, there are 2 types of

communication we will explore:

Synchronous communication Asynchronous communication

5.2 BLOCK 2: 12V, 1.2A BATTERY

In electricity, a battery is a device consisting of one or

more electrochemical cells that convert stored chemical energy into electrical

energy. Since the invention of the first battery (or "voltaic pile") in 1800

by Alessandro Volta and especially since the technically improved Daniell

cell in 1836, batteries have become a common power source for many

household and industrial applications. According to a 2005 estimate, the

worldwide battery industry generates US$48 billion in sales each year, with 6%

annual growth.

There are two types of batteries: primary batteries (disposable

batteries), which are designed to be used once and discarded, and secondary

batteries (rechargeable batteries), which are designed to be recharged and used

multiple times. Batteries come in many sizes from miniature cells used to

power hearing aids and wristwatches to battery banks the size of rooms that

provide standby power for telephone exchanges and computer data centers.

A battery is a device that converts chemical energy directly to

electrical energy. It consists of a number of voltaic cells; each voltaic cell

consists of two half-cells connected in series by a conductive electrolyte

containing anions and cautions.

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One half-cell includes electrolyte and the electrode to

which anions (negatively charged ions) migrate, i.e., the anode or negative

electrode; the other half-cell includes electrolyte and the electrode to

which cations (positively charged ions) migrate, i.e., the cathode or positive

electrode. In theredox reaction that powers the battery, cations are reduced

(electrons are added) at the cathode, while anions are oxidized (electrons are

removed) at the anode.

The electrodes do not touch each other but are electrically connected by

the electrolyte. Some cells use two half-cells with different electrolytes. A

separator between half-cells allows ions to flow, but prevents mixing of theelectrolytes. Each half-cell has an electromotive force (or emf), determined by

its ability to drive electric current from the interior to the exterior of the cell.

The net emf of the cell is the difference between the emfs of its half-cells, as

first recognized by Volta.

Therefore, if the electrodes have emfs and , then the net emf

is ; in other words, the net emf is the difference between the reductionpotentials of the half-reactions. The electrical driving force or across the

terminals of a cell is known as the terminal voltage (difference) and is measured

in volts the terminal voltage of a cell that is neither charging nor discharging is

called the open-circuit voltage and equals the emf of the cell. Because of

internal resistance, the terminal voltage of a cell that is discharging is smaller in

magnitude than the open-circuit voltage and the terminal voltage of a cell that is

charging exceeds the open-circuit voltage. An ideal cell has negligible internal

resistance, so it would maintain a constant terminal voltage of until

exhausted, then dropping to zero.

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If such a cell maintained 1.5 volts and stored a charge of

one coulomb then on complete discharge it would perform 1.5 joule of work. In

actual cells, the internal resistance increases under discharge,]and the open

circuit voltage also decreases under discharge. If the voltage and resistance are

plotted against time, the resulting graphs typically are a curve; the shape of the

curve varies according to the chemistry and internal arrangement employed.

As stated above, the voltage developed across a cell's terminals depends

on the energy release of the chemical reactions of its electrodes and electrolyte.

Alkaline and zinccarbon cells have different chemistries but approximately the

same emf of 1.5 volts; likewise NiCd and NiMH cells have differentchemistries, but approximately the same emf of 1.2 volts. On the other hand the

high electrochemical potential changes in the reactions of lithium compounds

give lithium cells emfs of 3 volts or more.

5.3 BLOCK 3: 12V SOLAR PANEL

5.3.1 Solar Electricity:

solar in the form of solar electric panels, hot water panels, and passive

heating; wind generators for electric production and windmills for water

pumping; and hydro electric generators. When people think about alternative or

renewable energy, the first image that comes to mind is often large blue or

black solar panels on rooftops or portable highway signs that have a small panel

attached. These panels, also known as photovoltaic modules (or PV modules),

convert sunlight into electricity, and they have been the backbone of renewable

energy for decades.

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The Photovoltaic Effect (how sunlight is converted into electrical energy)

was discovered over a hundred years ago! Yet widespread implementation of this

technology has been very gradual. Only in very recent years has photovoltaics

gained wide popularity as an alternative way to produce electricity. In 1958 the

first PV modules were launched into space to power satellites. Even today, solar

power is the primary source of energy at the International Space Station. On Earth

as well, PV has traditionally been used in areas where there is no practical source

of electrical power but there is abundant sunshine.

Solar panels are often used for remote applications: like powering cabins,

RVs, boats and small electronics when grid service is not available. Recently,

"grid-tie" solar electric systems have started gaining momentum as a cost-effective

way to incorporate solar electricity into our everyday lives. Now we can take

advantage of available solar energy while still enjoying the safety net of the utility

grid.

5.3.2 12 Volt Solar Panel:

When solar panels first came out they were really large and used only in

solar powerplants. As technology advanced, the sizes of solar panels were reduced

so that they could be installed on the rooftops of homes to generate and store hot

water. Now, many years later, they are able to store energy for the home owner,

traveler or boater. Nowadays we have several small to even tiny sized solar panels

and these solar panels are being used in such electrical devices as pocket

calculators and to charge up cell phones. Small solar panels are portable and can be

taken anywhere you want or need electrical power or battery recharging. You can

see them in carwindow sometimes as they are charging up the car battery.

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12v solar panel cells are really semiconductors that are made using

photovoltaic materials. Photovoltaic (PV) is the technical terminology that is

related to the solar energy and the conversion of the suns ultra-violet rays into

electrical energy. They do not have fluids or chemicals in them and they do not

have any moving parts. Solar panel cells simply convert the sunlight they receive

into stored energy with the help of an inverter. You can take a portable solar panel

with you when you travel to places that will not have electricity and use them to

operate your electrical devices such as your lap top, cell phone orappliances in a

camper van or trailer.

Some people take them out on their boats to supply the electricity they may

need out on the water. A 12v solar panel can store energy from the battery so that it

can be used at night when there is no sunlight available. You can use a 12v solar

panel with various electrical appliances. They are a convenient power supply for

charging mobile phones, personal stereos, PDAs and toys, etc. Some can be used

for trickle charging 12 volt batteries by using the power of the sun and no need for

an electrical outlet.

There have been several companies that have made the 12v solar panel

available to the public for personal use. Some of them can be used anywhere in the

world and are famous for their name brand and performance. Uni-Solar is one such

company that makes a good 12v solar panel that you can rely on, even in remote

places. This company has sold many such solar panels to the military for use out in

the field. The least expensive 12v solar panel that Uni -Solar makes is the UNI-PAC 10.

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This 12v solar panel chain be folded down to 254mm in length and 139mm

in width, with a depth of 51 mm. The UNI-PAC 10 offers dual voltage charging

for 12v and 24v.Uni-Solar also makes the UNI-PAC 15 and the UNI-PAC 34

solar panel systems. Both can be folded down like the UNI -PAC 10 for easy

portability. The only difference in measurement is that the UNI-PAC 15 is 27

mm slimmer and 18 mm shorter.

You can simply fold these up and take them with you and place them in the

sun at your destination so the solar panels can stay charged up and be ready for use

when you need power in remote places. A UNI-PAC 12v solar panel charger uses

innovative United Solar Systems Corp. Triple Junction Technology. This solar

panel charger is rugged and can be dropped or stepped on and still be able to

provide power. It will charge up a laptop in the middle of the desert for you if you

need it to. The time it takes to charge up .

5.3.3 Points To Remember:

1. Each 80watt panel fitted will require approximately 100 amp hours of battery

power.

2. When fitting a solar regulator 3 x 80watt panels will require a 15 amp regulator,

so you should consider fitting a 20 amp to enable you to fit an extra panel later if

required.

3. AGM batteries are fully sealed and entirely maintenance free. They do cost a bitmore but are completely safe when fitted inside caravans. We at Home of 12 Volt

highly recommend the use of AGM batteries.

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4. A 12 volt charge system from your vehicle will charge at a rate of approximately

30 amps and can be a handy option if you are a frequent traveller.

5. For best results, recharge at 10% of a batterys capacity. This can be done by

240 volt & solar charging.

6. For best results, wire your gas fridge to your caravan batteries and solar system

(less voltage drop means better performance).

7. Never run your fridge or charge your batteries from your 7 pin caravan plug as

this can result in a meltdown of your plug. It is recommended that an Anderson

system is used.

8. Finally keep it simple and enjoy your system.

APPROX SOLAR OUTPUT FOR 6 HOURS A DAY SUNLIGHT:

1 x 80 watt panel = 30 Amps

2 x 80 watt panels = 60 Amps

3 x 80 watt panels = 90 Amps

A system that requires 90 amps per day would require 3 x 80 watt panels

and batteries equivalent to 300 amp hours for continuous power supply.

Note: Your system will perform much better in summer than what it will in winter

due to the longer days and stronger sun.

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Keep in mind that batteries are rated in amp hours at 25c. This means that

temperature will affect the level of output that you will receive from your batteries.

When the temperature is colder than 25c you will receive less output from your

batteries, and in reverse, when temperature is above 25c you will receive a higher

output from your batteries. A quick and easy way to conserve power is to fit low

wattage fluro or L.E.D lighting. It is sometimes cheaper to change lighting than to

add another solar panel to your system.

Finally, it is good to remember that it is not a perfect world when fitting

solar panels to caravans as everybodys needs are different. But if you get it close

from the start you can and will learn to work with what you have and get the most

out of your system. By now you should know a bit more about solar and the system

that you may require. Remember to keep in mind that just because you now have

solar panels fitted to your caravan, it does not mean that you will not run our of

power. Even the most expensive systems can struggle to keep up with prolonged

periods of bad and overcast weather. It is now time to calculate your own needs

and build a system that will meet your requirements.

Points To Remember:

1 Amp at 12 Volts = 12 watts

1 Amp at 240 Volts = 240 watts

Amps x Volts = Watts EG 10Amps x 12 Volts = 120 wattsWatts / Volts = Amps EG 120 watts / 12 Volts = 10 Amps

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APPLIANCES WATT AGE X HOURS PER DAY USAGE = DAILY LOAD

KITCHEN LOUNGE 2 X 12 watt 3 = 72

AWNING 1 X 12 watt .5 = 6

BEDROOM 1 X 12 watt 1 = 12

SHOWER 1 X 18 watt 0.5 = 18

APPLIANCE = WATER PUMP 36 watt 0.5 = 18

5.3.4 Advantages Of Solar Panel:

o Solar energy is a renewable resource.o Solar cells are totally silent. They can extract energy from the sun

without making a peep.

o Solar energy is non-polluting. Solar cells require very littlemaintenance

o Solar powered lights and other solar powered products are also veryeasy to install. You do not even need to worry about wires.

5.3.5 Disadvantages Of Solar Panel:

o Solar cells/panels, etc. can be very expensive.o Solar power cannot be created at night.

5.4 BLOCK 4: LCD

5.4.1 Introduction

The most commonly used Character based LCDs are based on Hitachi's

HD44780 controller or other which are compatible with HD44580.

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In this tutorial, we will discuss about character based LCDs, their interfacing

with various microcontrollers, various interfaces (8-bit/4-bit), programming,

special stuff and tricks you can do with these simple looking LCDs which can give

a new look to your application.

5.4.2 Pin Description

The most commonly used LCDs found in the market today are 1 Line, 2

Line or 4 Line LCDs which have only 1 controller and support at most of 80

characters, whereas LCDs supporting more than 80 characters make use of 2HD44780 controllers. Most LCDs with 1 controller has 14 Pins and LCDs with 2

controller has 16 Pins (two pins are extra in both for back-light LED connections).

Pin description is shown in the table below.

Fig.5.4.2 Character LCD type HD44780 Pin diagram

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Table 5.4.2 a) Character LCD pins with 2 Controller

55

Pin No. Name Description

Pin no. 1 D7 Data bus line 7 (MSB)

Pin no. 2 D6 Data bus line 6

Pin no. 3D5

Data bus line 5





Pin no. 8 D0 Data bus line 0 (LSB)

Pin no. 9 EN1 Enable signal for row 0 and 1 (1stcontroller)

Pin no. 10 R/W0 = Write to LCD module

1 = Read from LCD module

Pin no. 11 RS0 = Instruction input

1 = Data input

Pin no. 12 VEE Contrast adjust

Pin no. 13 VSS Power supply (GND)

Pin no. 14 VCC Power supply (+5V)

Pin no. 15 EN2 Enable signal for row 2 and 3 (2nd

controller)

Pin no. 16 NC Not Connected


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Usually these days you will find single controller LCD modules are used

more in the market. So in the tutorial we will discuss more about the single

controller LCD, the operation and everything else is same for the double controller

too. Lets take a look at the basic information which is there in every LCD.

Although looking at the table you can make your own commands and test

them. Below is a brief list of useful commands which are used frequently while

working on the LCD.

* DDRAM address given in LCD basics section see Figure 2,3,4

* CGRAM address from 0x00 to 0x3F, 0x00 to 0x07 for char1 and so on.

No.Instruction Hex Decimal

1Function Set: 8-bit, 1 Line, 5x7

Dots0x30 48


Dots0x38 56


Dots0x20 32


Dots0x28 40

5 Entry Mode 0x06 6

6

Display off Cursor off

(clearing display without clearing

DDRAM content)

0x08 8


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7 Display on Cursor on 0x0E 14

8 Display on Cursor off 0x0C 12

9 Display on Cursor blinking 0x0F 15

10 Shift entire display left 0x18 24

12 Shift entire display right 0x1C 30

13 Move cursor left by one character 0x10 16

14 Move cursor right by one character 0x14 20

15Clear Display (also clear DDRAM

content)0x01 1

16Set DDRAM address or coursor

position on display0x80+add* 128+add*

17Set CGRAM address or set pointer

to CGRAM location0x40+add** 64+add**

5.4.2b ) Frequently used commands and instructions for LCD

5.5 BLOCK 5: CURRENT SENSOR

A current sensor is a device that detects electrical current (AC or DC) in a

wire, and generates a signal proportional to it. The generated signal could be

analog voltage or current or even digital output. It can be then utilized to display

the measured current in an ammeter or can be stored for further analysis in a data

acquisition system or can be utilized for control purpose.

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The sensed current and the output signal can be:

AC current input,o Analog output, which duplicates the wave shape of the sensed currento BIPOLAR output, which duplicates the wave shape of the sensed

current

o Unipolar output, which is proportional to the average or RMS valueof the sensed current.

DC current input,o Unipolar, with a unipolar output, which duplicates the wave shape of

the sensed current.

o Digital output, which switches when the sensed current exceeds acertain threshold.

Fig 5.5 Current Sensor

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Specification :Inductive step down Current transformer.

Input primary coil resistance : 1kilo ohms.

Output Secondary Series resistance : 20 ohms

Input Voltage Range : 150-300 Volts

Output Voltage range : 0.5 -1.5 Volts

5.6 BLOCK 6: VOLTAGE SENSOR

The Voltage Sensors are used to measure the potential difference

between the ends of an electrical component. The Voltage Sensors are equipped

with a micro controller that greatly improves the sensor accuracy, precision and

consistency of the readings. They are supplied calibrated and the stored calibration

(in Volts) is automatically loaded when the Voltage Sensor is connected.

Specification :Inductive step down voltage transformer.

Input voltage : 0250 volts

Primary coil Resistance : 1.5 Kilo ohms

Secondary Coil Resistance : 6 ohms

Maximum load Current : 1 Ampere

Gain division : 100

Output voltage : 0-2.50 Volts

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CHAPTER 6

CODING

6.1. ADC:

#include

#include"lcd.c"

#include"SERIAL.c"

void adc_init()

{

TRISA=0xFF;

TRISE=0x07;

ADCON0=0xC1;

ADCON1=0x80;

}

unsigned char adc()

{

unsigned char ah,al;

unsigned char val;

ADGO=1;

while(ADGO==1);

delay(500);

ah=ADRESH;

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al=ADRESL;

val=((ah*256)+al);

return(val);

}

void conversion(unsigned char temp)

{

unsigned char T,h,t,o;

T=(temp/1000);

h=((temp%1000)/100);

t=(((temp%1000)%100)/10);

o=(temp%10);

sertx(T+0x30);

sertx(h+0x30);

sertx(t+0x30);sertx(o+0x30);

sertx(0x0D);

lcddat(T+0x30);

lcddat(h+0x30);

lcddat(t+0x30);

lcddat(o+0x30);

}

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6.2. LCD :

#include

#define rs RC3

#define rw RC4

#define en RC5

void delay(unsigned int delay)

{

while(delay--);

}

void lcdcmd(unsigned char cmd)

{

PORTB=cmd;

rs=0;

rw=0;en=1;

delay(50);

en=0;

}

void lcddat(unsigned char dat)

{

PORTB=dat;

rs=1;

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rw=0;

en=1;

delay(50);

en=0;

}

void lcdstr(unsigned char *str)

{

while(*str)

{

lcddat(*str++);

} }

void lcdclr()

{

lcdcmd(0x01);delay(200);

}

void lcdinit()

{

lcdcmd(0x38);

lcdcmd(0x0C);

lcdclr();

lcdcmd(0x80) }

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6. 3. SERIAL:

#include

void serinit()

{

TXSTA=0x26;

SPEN=1;

//CREN=1;

SPBRG=25; }

/*unsigned char serrx()

{

unsigned char rx;

while(RCIF==0);

rx=RCREG;

RCIF=0;return(rx);

}*/

void sertx(unsigned char tx)

{

TXREG=tx;

while(TXIF==0);

TXIF=0;

}

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6. 4. KEYPAD:

#include

#include"serial.c"

void clr_r1(void)

{

RB0=0;

RB1=1;

RB2=1;

RB3=1;

}

void scan_c1(void)

{

if(RB4==0){

while(RB4==0);

sertx('0');

// sertx('7');

delay(500);

}

if(RB5==0)

{

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while(RB5==0);

sertx('1');

// sertx('8');

delay(500);

}

if(RB6==0)

{

while(RB6==0);

sertx('2');

// sertx('9');

delay(500);

}

if(RB7==0)

{while(RB7==0);

sertx('3');

// sertx('/');

delay(500);

}

}

void clr_r2(void)

{

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RB0=1;

RB1=0;

RB2=1;

RB3=1;

}

void scan_c2(void)

{

if(RB4==0)

{

while(RB4==0);

sertx('4');

// sertx('4');

delay(500);

}if(RB5==0)

{

while(RB5==0);

sertx('5');

// sertx('5');

delay(500);

}

if(RB6==0)

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{

while(RB6==0);

sertx('6');

// sertx('6');

delay(500);

}

if(RB7==0)

{

while(RB7==0);

sertx('7');

// sertx('*');

delay(500);

}

}void clr_r3(void)

{

RB0=1;

RB1=1;

RB2=0;

RB3=1;

}

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void scan_c3(void)

{

if(RB4==0)

{

while(RB4==0);

sertx('8');

// sertx('1');

delay(500);

}

if(RB5==0)

{

while(RB5==0);

sertx('9');

// sertx('2');delay(500);

} if(RB6==0)

{

while(RB6==0);

sertx('A');

// sertx('3');

delay(500);

}

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if(RB7==0)

{

while(RB7==0);

sertx('B');

// sertx('-');

delay(500);

}

}

void clr_r4(void)

{

RB0=1;

RB1=1;

RB2=1;

RB3=0;}

void scan_c4(void)

{

if(RB4==0)

{

while(RB4==0);

sertx('C');

// sertx(0x08);

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delay(500);

}

if(RB5==0)

{ while(RB5==0);

sertx('D');

// sertx('0');

delay(500);

}

if(RB6==0)

{ while(RB6==0);

sertx('E');

// sertx('=');

delay(500);}

if(RB7==0)

{ while(RB7==0);

sertx('F');

// sertx('+');

delay(500);

}

}

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6.5. SOFTWARE

6.5.1 CCS PIC-C compiler

The CCS PCW compiler is specially designed to meet the special needs ofthe pic micro MCU controllers. These tools allow developers to quickly design

application software for these controllers in a highly readable, high-level

language. The compilers has some limitations when compared to a more

traditional C Compiler. The hardware limitations make many traditional C

compilers Ineffective. As an example of the limitations, the compilers will not

permit Pointers to constant arrays.

This is due to the separate code/data segments in The picmicro MCU

hardware and the inability to treat ROM areas as data. On The other hand, the

compilers have knowledge about the hardware limitations And do the work of

deciding how to best implement your algorithms. The Compilers can efficiently

implement normal C constructs, input/output operations And bit twiddling

operations.

The compiler can output 8 bit hex, 16 bit hex, and binary files. Two

listing formats Are available. Standard format resembles the Microchip tools

and may be Required by some third-party tools. The simple format is easier to

read. The Debug file may either be a Microchip .COD file or Advanced Trans

data .MAP file. All file formats and extensions are selected via the Options File

Formats men Option in the Windows IDE.

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6.6 OVERALL STRUCTURE

A program is made up of the following four elements in a file:

Comment Pre-Processor Directive Data Definition Function Definition

Every C program must contain a main function which is the starting point

of the program execution. The program can be split into multiple functions

according to the their purpose and the functions could be called from main or the

sub functions. In a large project functions can also be placed in different C files or

header files that can be included in the main C file to group the related functions

by their category.

CCS C also requires to include the appropriate device file using#include directive to include the device specific functionality. There are also some

preprocessor directives like #fuses to specify the fuses for the chip and #use delay

to specify the clock speed. The functions contain the data declarations, definitions,

statements and expressions. The compiler also provides a large number of standard

C libraries as well as other device drivers that can be included and used in the

programs. CCS also provides a large number of built-in functions to access the

various peripherals included in the PIC microcontroller.

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Comments Standard CommentsA comment may appear anywhere within a file except within a quoted string.

Characters between /* and */ are ignored. Characters after a // up to the end of the

line are ignored.

Variable Comments A variable comment is a comment that appears

immediately after a variable declaration. For example:

int seconds; // Number of seconds since last entry

long day, // Current day of the month

month, /* Current Month */

year; // Year

Function CommentsA function comment is a comment that appears just before

a function declaration. For example:

// The following function initializes outputs

void function_foo()

{

init_outputs();

}

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Using Program Memory for DataConstant Data:

The const qualifier will place the variables into program memory. The

syntax is const type specifier id [cexpr] ={value}

If the keyword CONST is used before the identifier, the identifier is

treated as a constant. Constants should be initialized and may not be changed at

run-time.

For eg:

#ORG 0x1C00, 0x1C0F

CONST CHAR ID[10]= {"123456789"};

This ID will be at 1C00.

Note: some extra code will proceed the 123456789.

A new method allows the use of pointers to ROM. The new keyword for

compilation modes CCS4 and ANSI is ROM and for other modes it is

_ROM. This method does not contain extra code at the start of the structure.

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CHAPTER 7

REQUIREMENTS

7.1 HARDWARE REQUIREMENTS:

PIC16F877A Microcontroller with Power Supply 12V,1.2A Battery 12V Solar Panel LCD Tank Mechanism Current Sensor Voltage Sensor

7.2 SOFTWARE REQUIREMENTS

Embedded c MP Lab Compiler or CCS Compiler

7.3 ADVANTAGES

Energy efficient Long lasting and free maintenance . No dependency on electricity . Satisfactory performance on water pumping. User & environment friendly.

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CHAPTER 8

FUTURE ENHANCEMENT

In future, Upfront cost of the solar pumping system potentially hinder to

popularize the system in the rural areas but private companies, bank and govt. can

come forward for a solution that can fit to rural people of Bangladesh.

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CHAPTER 9

CONCLUSION

All components in the system can be procured from locally available markets

from nearby areas which eventually reduce the overall cost. The designed DC

water pumping system has a great prospect to solve out the energy crisis in the

irrigation season as well as it can be used to cultivate lands throughout the year.

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CHAPTER 10

REFERENCES

[1] Helikson,H.J and Others, Pumping water for irrigation using solar energy,

University of Florida, USA, 1995.

[2]Microcontrollerdatasheet.[Online].Available:http://www.datasheetcatalog.co

m/datasheets_pdf/A/T/M/E/ATMEGA32.shtml.

[3] Minor Irrigation Survey Report 2008-09, Bangladesh Agricultural

Development Corporation, Survey and monitoring project for development of

minor irrigation, June-2009.

[4] Rashid, Muhammad H. Power Electronics - Circuits, Devices, and Applications

3rd Edition Pearson Education, 2004

[5] The Daily Prothom Alo, 4th November, 2009, web page available:

http://www.prothom-alo.com/detail/date/2009-11-04/news/17114

[6] WATTSUNTM SOLAR TRACKER RETAIL PRICE AND DATA

Documents

Raja Sekar An