Most of the circuits in by XP3pjet8


A project Report submitted in partial fulfilment of the requirement
                        for the award of

                   Bachelor of Technology
      Electronics & Communication Engineering
     1. RUPA TULASI.M                 2. VIJAY KUMAR.B
      3. SANKARA RAO.B                4. NARESH REDDY.T

            Under the Esteemed Guidance of
                  P.Venkateswara Rao

Asst.Professor, in Electronics & communication Engineering
 Department of Electronics & Communication Engineering

Vikas College of Engineering & Technology
               NUNNA-52121, VIJAYAWADA RURAL.








     Embedded Systems
     Power supply
     Transformer
     Rectifiers
     Regulators
     Microcontroller description




                     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

                             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.

       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






                                    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

                             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

                               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.


             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
                                     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.

              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.

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


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


       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
which can provide this regular power supply.
       The 78xx Series of Regulators

       There are many types of regulator IC and each type will have different pin-outs and
will need to be connected up slightly differently. Therefore, this article will only look at one
of the common ranges of regulator, the 78xx series.

       There are seven regulators in the 78xx series, and each can pass up to 1A to any
connected circuit. There are also regulators with similar type numbers that can pass a higher
or lower current, as shown in the table below. In addition, variable regulators are available,
as are regulators that can provide negative regulation voltages for circuits that require them.
Here we are representing the regulators used in this project.


     7805                      +5V                    1A                             +7V

     7812                      +12V                   1A                             +14.5V

   If you are using a regulator after the smoothing block of the power supply, then you
shouldn't need to worry about the ripple voltage, since the whole point of using a regulator is
to get a stable, accurate, known voltage for your circuits!

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes
of in-system programmable Flash memory. The device is manufactured using Atmel’s high-
density non-volatile memory technology and is compatible with the industry-standard 80C51
instruction set and pin out. By combining a versatile 8-bit CPU with in-system programmable
Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides
a highly-flexible and cost-effective solution to many embedded control applications. The
AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32
I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-
level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In
addition, the AT89S52 is designed with static logic for operation down to zero frequency and
supports two software selectable power saving modes. The Idle Mode stops the CPU while
allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning.

                                        Pin diagram
Pin Description:
 VCC - Supply voltage.
 GND - Ground.

 Port 0
           Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can
sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high
impedance inputs. Port 0 can also be configured to be the multiplexed low order address/data
bus during accesses to external program and data memory.

Port 1
          Port 1 is an 8-bit bidirectional I/O port with internal pull ups. The Port 1 output
buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled
high by the internal pull ups and can be used as inputs. As inputs, Port 1 pins that are
externally being pulled low will source current (IIL) because of the internal pull ups.

Port 2
          Port 2 is an 8-bit bidirectional I/O port with internal pull ups. The Port 2 output
buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled
high by the internal pull ups and can be used as inputs. As inputs, Port 2 pins that are
externally being pulled low will source current (IIL) because of the internal pull ups.

Port 3
         Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output
buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled
high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are
externally being pulled low will source current (IIL) because of the pull-ups.

      Reset input. A high on this pin for two machine cycles while the oscillator is running
resets the device. This pin drives High for 96 oscillator periods after the Watchdog times out.
The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature.
      Address Latch Enable (ALE) is an output pulse for latching the low byte of the address
during accesses to external memory. This pin is also the program pulse input (PROG) during
Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the
oscillator frequency and may be used for external timing or clocking purposes.

    Program Store Enable (PSEN) is the read strobe to external program memory. When the
AT89S52 is executing code from external program memory, PSEN is activated twice each
machine cycle, except that two PSEN activations are skipped during each access to external
data memory.

    External Access Enable. EA must be strapped to GND in order to enable the device to
fetch code from external program memory locations starting at 0000H up to FFFFH. This pin
also receives the 12-volt programming enable voltage (VPP) during Flash programming.

    Input to the inverting oscillator amplifier and input to the internal clock operating circuit.

   Output from the inverting oscillator amplifier.

        In order to control the robot, you need to make a call to the cell phone attached to the
robot (through head phone) from any phone, which sends DTMF tunes on pressing the
numeric buttons. The cell phone in the robot is kept in ‘auto answer’ mode. (If the mobile
does not have the auto answering facility, receive the call by ‘OK’ key on the robot-
connected mobile and then made it in hands-free mode). So after a ring, the cell phone
accepts the call. Now you may press any button on your mobile to perform actions. The
DTMF tones thus produced are received by the cell phone in the robot. These tones are fed to
the circuit by the headset of the cell phone.

                 The CM8870 decodes the received tone and sends the equivalent binary
number to the microcontroller. According to the program in the microcontroller, the robot
starts moving. When you press key ‘2’ (binary equivalent 00000010) on your mobile phone,
the microcontroller outputs ‘10001001’ binary equivalent. Port pins PD0, PD3 and PD7 are
high. The high output at PD7 of the microcontroller drives the motor driver (L293D). Port
pins PD0 and PD3 drive motors M1 and M2 in forward direction. Similarly, motors M1 and
M2 move for left turn, right turn, backward motion and stop condition.

What Is DTMF…….?

                               Dual-tone multi-frequency (DTMF) signalling is used for telephone
signalling over the line in the voice-frequency band to the call switching center. The version of DTMF
used for telephone tone dialling is known by the trademarked term Touch-Tone, and is standardized
by ITU-T Recommendation. Other multi-frequency systems are used for signalling internal to the
telephone network.

                                           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. Atone 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. 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

In DTMF system the tones and assignments are as follows

The data of the buttons:
                      SOFTWARE DESCRIPTION
Software’s used are:
*Keil software for c programming

*Express PCB for lay out design

*Express SCH for schematic design

What's New in µVision3?

µVision3 adds many new features to the Editor like Text Templates, Quick Function Navigation, and
Syntax Coloring with brace high lighting Configuration Wizard for dialog based start-up and
debugger setup. µVision3 is fully compatible to µVision2 and can be used in parallel with µVision2.

What is µVision3?

µVision3 is an IDE (Integrated Development Environment) that helps you write, compile, and debug
embedded programs. It encapsulates the following components:

       A project manager.
       A make facility.
       Tool configuration.
       Editor.
       A powerful debugger.
To help you get started, several example programs (located in the \C51\Examples, \C251\Examples,
\C166\Examples, and \ARM\...\Examples) are provided.

       HELLO is a simple program that prints the string "Hello World" using the Serial Interface.
       MEASURE is a data acquisition system for analog and digital systems.
       TRAFFIC is a traffic light controller with the RTX Tiny operating system.
       SIEVE is the SIEVE Benchmark.
       DHRY is the Dhrystone Benchmark.
       WHETS are the Single-Precision Whetstone Benchmark.
Additional example programs not listed here are provided for each device architecture.

Building an Application in µVision2

To build (compile, assemble, and link) an application in µVision2, you must:

    1. Select Project -(forexample,166\EXAMPLES\HELLO\HELLO.UV2).
    2. Select Project - Rebuild all target files or Build target.
    3. Creating Your Own Application in µVision2
   To create a new project in µVision2, you must:

    1. Select Project - New Project.
    2. Select a directory and enter the name of the project file.
    3. Select Project - Select Device and select an 8051, 251, or C16x/ST10 device from the Device
    4. Create source files to add to the project.
    5. Select Project - Targets, Groups, and Files. Add/Files, select Source Group1, and add the
        source files to the project.
    6. Select Project - Options and set the tool options. Note when you select the target device from
        the Device Database™ all special options are set automatically. You typically only need to
        configure the memory map of your target hardware. Default memory model settings are
        optimal for most applications.
    7. Select Project - Rebuild all target files or Build target.

Debugging an Application in µVision2

To debug an application created using µVision2, you must:

    1. Select Debug - Start/Stop Debug Session.
    2. Use the Step toolbar buttons to single-step through your program. You may enter G, main in
        the Output Window to execute to the main C function.
    3. Open the Serial Window using the Serial #1 button on the toolbar.
Debug your program using standard options like Step, Go, Break, and so on.

Starting µVision2 and Creating a Project

µVision2 is a standard Windows application and started by clicking on the program icon. To create a
new project file select from the µVision2 menu

Project – New Project…. This opens a standard Windows dialog that asks you

for the new project file name.

We suggest that you use a separate folder for each project. You can simply use

the icon Create New Folder in this dialog to get a new empty folder. Then

select this folder and enter the file name for the new project, i.e. Project1.

µVision2 creates a new project file with the name PROJECT1.UV2 which contains
a default target and file group name. You can see these names in the Project

Window – Files.

Now use from the menu Project – Select Device for Target and select a CPU

for your project. The Select Device dialog box shows the µVision2 device

database. Just select the microcontroller you use. We are using for our examples the Philips
80C51RD+ CPU. This selection sets necessary tool

options for the 80C51RD+ device and simplifies in this way the tool Configuration

Building Projects and Creating a HEX Files

Typical, the tool settings under Options – Target are all you need to start a new

application. You may translate all source files and line the application with a

Click on the Build Target toolbar icon. When you build an application with

syntax errors, µVision2 will display errors and warning messages in the Output

Window – Build page. A double click on a message line opens the source file

on the correct location in a µVision2 editor window.

Once you have successfully generated your application you can start debugging.

        After you have tested your application, it is required to create an Intel HEX file to download
the software into an EPROM programmer or simulator. µVision2 creates HEX files with each build
process when Create HEX files under Options for Target – Output is enabled. You may start your
PROM programming utility after the make process when you specify the program under the option
Run User Program #1.

CPU Simulation

µVision2 simulates up to 16 Mbytes of memory from which areas can be

mapped for read, write, or code execution access. The µVision2 simulator traps

and reports illegal memory accesses.

In addition to memory mapping, the simulator also provides support for the
integrated peripherals of the various 8051 derivatives. The on-chip peripherals

Of the CPU you have selected are configured from the Device

Database selection

You have made when you create your project target. Refer to page 58 for more

Information about selecting a device. You may select and display the on-chip peripheral components
using the Debug menu. You can also change the aspects of each peripheral using the controls in the
dialog boxes.

Start Debugging

You start the debug mode of µVision2 with the Debug – Start/Stop Debug

Session command. Depending on the Options for Target – Debug

Configuration, µVision2 will load the application program and run the start-up

code µVision2 saves the editor screen layout and restores the screen layout of the last debug session.
If the program execution stops, µVision2 opens an

Editor window with the source text or shows CPU instructions in the disassembly window. The next
executable statement is marked with a yellow arrow. During debugging, most editor features are still

For example, you can use the find command or correct program errors. Program source text of your
application is shown in the same windows. The µVision2 debug mode differs from the edit mode in
the following aspects:

_ The “Debug Menu and Debug Commands” described on page 28 are

Available. The additional debug windows are discussed in the following.

_ The project structure or tool parameters cannot be modified. All build

Commands are disabled.
Disassembly Window

The Disassembly window shows your target program as mixed source and assembly program or just
assembly code. A trace history of previously executed instructions may be displayed with Debug –
View Trace Records. To enable the trace history, set Debug – Enable/Disable Trace Recording.

If you select the Disassembly Window as the active window all program step commands work on
CPU instruction level rather than program source lines. You can select a text line and set or modify
code breakpoints using toolbar buttons or the context menu commands.

         You may use the dialog Debug – Inline Assembly… to modify the CPU instructions. That
allows you to correct mistakes or to make temporary changes to the target program you are


   1.        Click on the Keil u Vision Icon on Desktop
   2.        The following fig will appear

   3.        Click on the Project menu from the title bar
4.   Then Click on New Project

5.   Save the Project by typing suitable project name with no extension in u r own folder sited
     in either C:\ or D:\

6.   Then Click on save button above.
7.   Select the component for u r project. i.e. Atmel……
8.    Click on the + Symbol beside of Atmel

9.    Select AT89C51 as shown below

10.   Then Click on “OK”
11.   The Following fig will appear
12.   Then Click either YES or NO………mostly “NO”
13.   Now your project is ready to USE
14.   Now double click on the Target1, you would get another option “Source group 1” as
      shown in next page.

15.   Click on the file option from menu bar and select “new”
16.   The next screen will be as shown in next page, and just maximize it by double clicking on
      its blue boarder.

17.   Now start writing program in either in “C” or “ASM”
18.   For a program written in Assembly, then save it with extension “. asm” and for “C”
      based program save it with extension “ .C”
19.   Now right click on Source group 1 and click on “Add files to Group Source”

20.   Now you will get another window, on which by default “C” files will appear.
21.   Now select as per your file extension given while saving the file
22.   Click only one time on option “ADD”
23.   Now Press function key F7 to compile. Any error will appear if so happen.

24.   If the file contains no error, then press Control+F5 simultaneously.
25.   The new window is as follows
26.   Then Click “OK”
27.   Now Click on the Peripherals from menu bar, and check your required port as
      shown in fig below

28.   Drag the port a side and click in the program file.
29.     Now keep Pressing function key “F11” slowly and observe.
30.     You are running your program successfully

      The project is not only limited to simple functioning of the robot that is to move forward,
backward, right and left, but it can also be implemented with camera to watch what is going out
in particular location of the floor in a close circuit monitor or /and with a voice recorder to even
record the conversation going on in a room. This definitely requires a difficult circuitry. Thus it
is up to the maker what he/she wants his/her robot to be like: SIMPLE (like ours) or
SOPHISTICATED…as described further.

        Remote control vehicles have various scientific uses including hazardous environments,
        working in deep oceans, and space exploration. The majority of the probes to the other
        planets in our solar system have been remote control vehicles, although some of the
        more recent ones were partially autonomous. The sophistication of these devices has
        fueled greater debate on the need for manned spaceflight and exploration.
2) Military and Law Enforcement:

                  Military usage of remotely controlled military vehicles dates back to the
     first half of 20th century. Soviet Red Army used remotely controlled Tele tanks during
     1930s in the Winter War and early stage of World War II.

3) Search and Rescue:

                     UAVs will likely play an increased role in search and rescue in the
     United States. This was demonstrated by the successful use of UAVs during the 2008
     hurricanes that struck Louisiana and Texas. Thus the required connection which is to be
     made with the ear piece that is the connections with the tip and the ring is to be taken
     care of, because it is this which will make the circuit to work as desired. If the wire is
     not connected properly the robot will not function. The ring of the hands free is shown
     with number 1 while the tip is with number 2

4) Recreation and Hobby:

                      See Radio-controlled model. Small scale remote control vehicles have
     long been popular among hobbyists. These remote controlled vehicles span a wide range
     in terms of price and sophistication. There are many types of radio controlled vehicles.
     These include on-road cars, off-road trucks, boats, airplanes, and even helicopters. The
     "robots" now popular in television shows such as Robot Wars, are a recent extension of
     this hobby (these vehicles do not meet the classical definition of a robot; they are
     remotely controlled by a human).

Thus, this robot can move to any place where even man cannot enter and collects the
information through a camera attached to it. The robot is being controlled by the mobile.
The information collected by the robot is seen in the personal computer. This project finds a
wide range of application in military purposes besides its general purpose applications.


1. IR Sensors:

          IR sensors can be used to automatically detect & avoid obstacles if the robot goes beyond line of
 sight. This avoids damage to the vehicle if we are manoeuvring it from a distant place.

2. Password Protection:

        Project can be modified in order to password protect the robot so that it can be operated only if
correct password is entered. Either cell phone should be password protected or necessary modification
should be made in the assembly language code. This introduces conditioned access & increases security to
a great extent.

3. Alarm Phone Dialler:

                        By replacing DTMF Decoder IC CM8870 by a 'DTMF Transceiver IC‟ CM8880,
DTMF tones can be generated from the robot. So, a project called 'Alarm Phone Dialler' can be built which
will generate necessary alarms for something that is desired to be monitored (usually by triggering a relay).
For example, a high water alarm, low temperature alarm, opening of back window, garage door, etc.

When the system is activated it will call a number of programmed numbers to let the user know the alarm
has been activated. This would be great to get alerts of alarm conditions from home when user is at work.

1. Wikipedia - The free encyclopaedia
4. Schenker, L (1960), "Pushbutton Calling with a Two-Group Voice- Frequency Code” The
Bell system technical journal.
6. California micro
7. “DTMF Tester” , „Electronics For You‟ Magazine , Edition (June 2003)

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