MOBILE OPERATED LAND ROVER FOR NAVIGATION A project Report submitted in partial fulfilment of the requirement for the award of Bachelor of Technology In Electronics & Communication Engineering Submitted By 1. RUPA TULASI.M 2. VIJAY KUMAR.B 3. SANKARA RAO.B 4. NARESH REDDY.T Under the Esteemed Guidance of P.Venkateswara Rao M.Tech Asst.Professor, in Electronics & communication Engineering
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MOBILE OPERATED LAND ROVER FOR NAVIGATION
A project Report submitted in partial fulfilment of the requirement for the award of
Bachelor of Technology
In
Electronics & Communication Engineering
Submitted
By
1. RUPA TULASI.M 2. VIJAY KUMAR.B
3. SANKARA RAO.B 4. NARESH REDDY.T
Under the Esteemed Guidance of
P.Venkateswara Rao
M.Tech
Asst.Professor, in Electronics & communication Engineering
Department of Electronics & Communication Engineering
Vikas College of Engineering & Technology
NUNNA-52121, VIJAYAWADA RURAL.
2008-2012.
INDEX
1. ABSTRACT
2. INTRODUCTION
3. BLOCK DIAGRAM
4. BLOCK DIAGRAM EXPLANATION
5. SCHEMATIC DIAGRAM
6. SCHEMATIC DIAGRAM EXPLANATION
7. HARDWARE DESCRIPTION
Embedded Systems Power supply Transformer Rectifiers Regulators Microcontroller description
8. SOFTWARE DESCRIPTION
9. CONCLUSION
10. BIBILOGRAPHY
ABSTRACT
In this project, the robot is controlled by a cell phone that makes
a call to the mobile phone attached to the robot. In the course of a call, the cell phone
is assigned to automatic answer button is activated. A tone corresponding to the
button pressed is heard at the other end of the call. This tone is called ‘dual-tone
multiple-frequency’ (DTMF) tone. The robot perceives this DTMF tone with the help
of the phone stacked in the robot. The received tone is processed by the AT89S52
microcontroller with the help of DTMF decoder CM8870. The decoder decodes the
DTMF tone into its equivalent binary digit and this binary number is sent to the
microcontroller.
The microcontroller is pre-programmed to take a
decision for any given input and outputs its decision to motor drivers in order to drive
the motors for forward or backward motion or a turn. The mobile that makes a call to
the mobile phone stacked in the robot acts as a remote. So this simple robotic project
does not require the construction of receiver and transmitter units.
DTMF signalling is used for telephone signalling
over the line in the voice-frequency band to the call switching centre. The version of
DTMF used for telephone tone dialling is known as ‘Touch-Tone’ DTMF assigns a
specific frequency (consisting of two separate tones) to each key so that it can easily
be identified by the electronic circuit. The signal generated by the DTMF encoder is a
direct algebraic summation, in real time, of the amplitudes of two sine (cosine)waves
of different frequencies, i.e., pressing ‘5’ will send a tone made by adding 1336 Hz
and 770 Hz to the other end of the line. Then the command is done with the frequency
assigned to it. Then the robot move according to the commands given by the user.
INTRODUCTION
Conventionally, wireless-controlled robots use RF circuits, which have the drawbacks of
limited working range, limited frequency range and limited control. Use of a mobile phone for
robotic control can overcome these limitations. It provides the advantages of robust control,
working range as large as the coverage area of the service provider, no interference with other
controllers and up to twelve controls.
Although the appearance and capabilities of robots vary vastly,
all robots share the features of a mechanical, movable structure under some form of control. The
control of robot involves three distinct phases: reception, processing and action. Generally, the
preceptors are sensors mounted on the robot, processing is done by the on-board microcontroller
or processor, and the task (action) is performed using motors or with some other actuators. In this
project the robot is operated with the help of cell phone using the DTMF technology which is
assigned in the cell phones.
BLOCK DIAGRAM
Receiver:
Transmitter:
Dtmf circuit
AT89S52 Microcontroller
Driver
DriverMotor-1
Motor-2
Video Cam
BLOCK DIAGRAM EXPLANATION
Here in this block diagram we are using two cell
phones. One of the two cell phones is used as the transmitter. From this transmitter cell
phone, we are sending the DTMF signal to another cell phone which is the robotic car.
A cell phone which receives the signal from the transmitter will give the signal to DTMF
(mt8870). From that DTMF it sends the binary signals to the micro controller which already
has a program written into the micro controller according to the users specifications.
The motor will drive the robotic car according to the instruction given by the micro
controller.
SCHEMATIC DIAGRAM
SCHEMATIC DIAGRAM EXPLANATION
We apply a 230v AC source of 12-0-12 transformer, which is a
step down transformer. This step down transformer gives 12v AC. Using a bridge rectifier we
can change the AC voltage to DC voltage. This voltage is applied to 7805 voltage regulator
which in turn gives a constant 5v DC configuration. The output of 7805 voltage regulator is
applied to 40th pin of microcontroller. A mobile is used here to transmit the signals and this
mobile acts as a transmitter. Here we use DTMF which receives the signals sent from the
mobile.
The data given to the mobile is transmitted through DTMF
pins 11,12,13,14,15 to the microcontroller port-1 pins 4,5,6,7,8 respectively. Microcontroller
transmits the data from its port-2 pins 21,22,23,24 to L293D input pins 2,7,10,15. And the
output pins 3,5,11,14 are connected to the first motor. The L293D pins 1,8,9,16 are shorted.
The output pins 13,14 of the microcontroller at port-3 are connected to the L239D input pins
2,7. The output pins 3,6 are connected to the another motor. These motors can rotate.
DUAL TONE MULTIPLE FREQUENCY (DTMF) CIRCUIT
CIRCUIT DESCRIPTION:
The CM8870 provides full DTMF receiver capability by integrating both the band
split filter and digital decoder functions into a single 18-pin IC or 20-pin PLCC package. The
CM8870 is manufactured using state-of-the-art CMOS process technology for low power
consumption (35mW, max.) and precise data handling. The filter section uses a switched
capacitor technique for both high and low group filters and dial tone rejection. TheCM8870
decoder uses digital counting techniques for the detection and decoding of all 16 DTMF tone
pairs into a 4-bit code. This DTMF receiver minimizes external component count by providing
an on-chip differential input amplifier, clock generator, and a latched three-state interface bus.
HARDWARE DESCRIPTION
EMBEDDED SYSTEMS
Embedded systems are designed to do some specific task, rather than be a general-purpose
computer for multiple tasks. Some also have real time performance constraints that must be
met, for reason such as safety and usability; others may have low or no performance
requirements, allowing the system hardware to be simplified to reduce costs.
An embedded system is not always a separate block - very it is physically built-in
to the device it is controlling. The software written for embedded systems is often called
firmware, and is stored in read-only memory or flash convector chips rather than a disk drive.
It often runs with limited computer hardware resources: small or no keyboard, screen, and
little memory.
Wireless communication has become an important feature for commercial products
and a popular research topic within the last ten years. There are now more mobile phone
subscriptions than wired-line subscriptions. Lately, one area of commercial interest has been
low-cost, low-power, and short-distance wireless communication used for \personal wireless
networks." Technology advancements are providing smaller and more cost effective devices
for integrating computational processing, wireless communication, and a host of other
functionalities. These embedded communications devices will be integrated into applications
ranging from homeland security to industry automation and monitoring. They will also
enable custom tailored engineering solutions, creating a revolutionary way of disseminating
and processing information. With new technologies and devices come new business
activities, and the need for employees in these technological areas. Engineers who have
knowledge of embedded systems and wireless communications will be in high demand.
Unfortunately, there are few adorable environments available for development and classroom
use, so students often do not learn about these technologies during hands-on lab exercises.
The communication mediums were twisted pair, optical fiber, infrared, and generally wireless
radio.
POWER SUPPLY
Most of the circuits in Electronics need a smooth DC power supply in order to
function correctly. Some other circuits, particularly those using digital ICs, also need their
power supply to be regulated. In this article and the articles that follow in this series you will
learn the meaning of terms such as 'smoothing' and 'regulation' and find out how to build a
simple power supply for your circuits.
What Are AC And DC?
A representation of an Alternating Current (AC) supply is shown in figure 1. The
voltage (and current) alternates between positive and negative over time and the resulting
waveform shape is a sine wave. In the case of the UK mains supply, the frequency of this
sine wave is 50Hz, or 50 cycles per second.
A Direct Current (DC) supply, shown in figure 2, stays at a fixed, regular, voltage all of the
time, like the voltage from a battery. A DC supply is needed by most circuits as a constant
reference voltage. Also, some components would be damaged by the negative half-cycles of
an AC supply.
The Parts of a Power Supply:
Building the 5V Regulated Power Supply
Figure 4 gives a strip board layout for the 5V regulated power supply shown in figure 4. The layout does not include the transformer block, so the input to the board needs to be 7 - 35V AC from a Suitable transformer.
The layout includes space for two optional 2-way screw terminal blocks to make connecting
up the power supply easier.
If the input voltage is 9V AC, you will be able to draw 1A from the power supply. For the
maximum input voltage of 35V you will be able to draw 0.1A.
Transformer
A suitable ready-built mains power supply unit, such as those used to control model
trains, will include a transformer. I wouldn't recommend building your own due to the safety
considerations when dealing with mains voltages. If such a unit does not incorporate smoothing,
rectification, and regulation, then you will need to build these blocks as described in part 1 of this
series. If the unit does not have a fuse or a cut-out on the output of the transformer, you will also
need to add a fuse of an appropriate rating. This fuse is in addition to the mains fuse in the unit's
plug and is needed to protect the low voltage winding of the transformer and any circuits you
connect to it. Although we won't be building the transformer block of our 5V regulated power
supply, it is interesting to know how it works.
Rectifier
The purpose of a rectifier is to convert an AC waveform into a DC waveform. There are two
different rectification circuits, known as 'half-wave' and 'full-wave' rectifiers. Both use
components called diodes to convert AC into DC. A diode is a device which only allows
current to flow through it in one direction. In this direction, the diode is said to be 'forward-
biased' and the only effect on the signal is that there will be a voltage loss of around 0.7V. In
the opposite direction, the diode is said to be 'reverse-biased' and no current will flow through
it.
BRIDGE RECTFIER:
A diode bridge is an arrangement of four (or more) diodes in a bridge configuration that
provides the same polarity of output for either polarity of input. When used in its most
common application, for conversion of an alternating current (AC) input into direct current a
(DC) output, it is known as a bridge rectifier.
Basic operation:
According to the conventional model of current flow originally established by Benjamin
Franklin and still followed by most engineers today, current is assumed to flow through
electrical conductors from the positive to the negative pole. In actuality, free electrons in a
conductor nearly always flow from the negative to the positive pole. In the vast majority of
applications, however, the actual direction of current flow is irrelevant. Therefore, in the
discussion below the conventional model is retained.
In the diagrams below, when the input connected to the left corner of the diamond is
positive, and the input connected to the right corner is negative, current flows from the
upper supply terminal to the right along the red (positive) path to the output, and returns to
the lower supply terminal via the blue (negative) path.
When the input connected to the left corner is negative, and the input connected to the
right corner is positive, current flows from the upper supply terminal to the right along the
red (positive) path to the output, and returns to the lower supply terminal via the blue
(negative) path
Regulator
While there are many circuits that will tolerate a smoothed power supply, some must
have a completely regular supply with no ripple voltage. This article discusses regulator ICs