Automatic Room Light Control With Bi Directional Visitor

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AUTOMATIC ROOM LIGHT CONTROL WITHBI DIRECTIONAL VISITORCOUNTERFiled under: Automatic room light Control with bi directional visitor counter circuit,Circuti

Ideas, Uncategorized by IndianEngineer Leave a comment

May 12, 2010

Project title is AUTOMATIC ROOM LIGHT CONTROLLER WITH BIDIRECTIONAL

VISITOR COUNTER . mICROCONTROLLER BASED PROJECT

The objective of this project is to make a controller based model to count number of

persons visiting particular room and accordingly light up the room. Here we can use

sensor and can know present number of persons.

In todays world, there is a continuous need for automatic appliances with the

increase in standard of living, there is a sense of urgency for developing circuits

that would ease the complexity of life.

Also if at all one wants to know the number of people present in room so as not to

have congestion. This circuit proves to be helpful.

CIRCUIT DIAGRAM

Automatic room light Control with bi directional visitor counter circuit

RECEIVER CIRCUIT

The IR transmitter will emit modulated 38 kHz IR signal and at the receiver we useTSOP1738 (Infrared Sensor). The output goes high when the there is an interruption

and it return back to low after the time period determined by the capacitor and

resistor in the circuit. I.e. around 1 second. CL100 is to trigger the IC555 which is

configured as monostable multivibrator. Input is given to the Port 1 of the

microcontroller. Port 0 is used for the 7-Segment display purpose. Port 2 is used for
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the Relay Turn On and Turn off Purpose.LTS 542 (Common Anode) is used for 7-

Segment display. And that time Relay will get Voltage and triggered so light will get

voltage and it will turn on. And when counter will be 00 that time Relay will be

turned off. Reset button will reset the microcontroller.Microcontroller based Visitor

Counter.

TRANSMISSION CIRCUIT

This circuit diagram shows how a 555 timer IC is configured to function as a basic

monostable multivibrator. A monostable multivibrator is a timing circuit that

changes state once triggered, but returns to its original state after a certain timedelay. It got its name from the fact that only one of its output states is stable. It is

also known as a one-shot.

In this circuit, a negative pulse applied at pin 2 triggers an internal flip-flop that

turns off pin 7s discharge transistor, allowing C1 to charge up through

R1. At the same time, the flip-flop brings the output (pin 3) level to high. When

capacitor C1 as charged up to about 2/3 Vcc, the flip-flop is triggered once again,

this time making the pin 3 output low and turning on pin 7s discharge transistor,

which discharges C1 to ground. This circuit, in effect, produces a pulse at pin 3

whose width t is just the product of R1 and C1, i.e., t=R1C1.

IR Transmission circuit is used to generate the modulated 36 kHz IR signal. The

IC555 in the transmitter side is to generate 36 kHz square wave. Adjust the preset

in the transmitter to get a 38 kHz signal at the o/p. around 1.4K we get a 38 kHz

signal. Then you point it over the sensor and its o/p will go low when it senses the IR

signal of 38 kHz.
http://projectsworld.files.wordpress.com/2010/05/room1.png


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PCB LAYOUT

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GSM Based Home Security System

Abstract Home security has been a major issue where crime is increasing and everybody wants to

take proper measures to prevent intrusion. In addition there was a need to automate homeso that user can take advantage of the technological advancement in such a way that a

person getting off the office does not get melted with the hot climate.

Introduction

The project is aimed at developing the security of Home against Intruders , Gas Leak and

Fire . In any of the above three cases any one met while you are out of your home than

the device sends SMS to the emergency no provided to it. The report consists of a background into the area of 8051 microcontroller and mobile

communication, how they are interfaced to each other and AT (Attention) commands set

used in communication.

HARDWARE USED

1. AT command supporting GSM mobile phone.
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2. 89S52 Microcontroller

3. Max 232 IC.

4. Relays

5. Relay driver IC ULN 2803

6. Voltage regulator 7805.

7. Diode IN4007

8. GSM Phone

9. LPG Gas Sensor

SOFTWARE USED

1. Keil u-Vision 3.0

Keil Software is used provide you with software development tools for 8051 based

microcontrollers. With the Keil tools, you can generate embedded applications forvirtually every 8051 derivative. The supported microcontrollers are listed in the -vision

2. PRO51 Programmer Software

THEORY OF OPERATION

In this project we interfaced 8051 microcontroller with Motorolas C168 GSMmobile phone to decode the received message and do the required action. Theprotocol used for the communication between the two is AT command.

The microcontroller pulls the SMS received by phone, decode it, recognizes the Mobile no. and then switches on the relays attached to its port to control the

appliances. After successful operation, controller sends back acknowledgement to the users mobile through SMS.

AT-Command set

The following section describes the AT-Command set. The commands can be tried out byconnecting a GSM modem to one of the PCs COM ports. Type in the test-command,

adding CR + LF (Carriage return + Line feed = \r\n) before executing. Table gives an

overview of the implemented AT-Commands in this application. The use of the

commands is described in the later sections.

AT-Command set overview

Command Description

AT Check if serial interface and GSM modem is


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working.

ATE0 Turn echo off, less traffic on serial line.

AT+CNMI Display of new incoming SMS.

AT+CPMS Selection of SMS memory.

AT+CMGF SMS string format, how they are compressed.

AT+CMGR

Read new message from a given memory

location.

AT+CMGS Send message to a given recipient.

AT+CMGD Delete message.

A BRIEF INTRODUCTION TO 8051

MICROCONTROLLER:

When we have to learn about a new computer we have to familiarize about the

machine capability we are using, and we can do it by studying the internal hardwaredesign (devices architecture), and also to know about the size, number and the size of the

registers.

A microcontroller is a single chip that contains the processor (the CPU), non-volatile memory for the program (ROM or flash), volatile memory for input and output(RAM), a clock and an I/O control unit. Also called a "computer on a chip," billions of

microcontroller units (MCUs) are embedded each year in a myriad of products from toys

to appliances to automobiles. For example, a single vehicle can use 70 or moremicrocontrollers. The following picture describes a general block diagra

microcontroller.

89s52: The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller

with 8K bytes of in-system programmable Flash memory. The device is manufacturedusing Atmels high-density nonvolatile memory technology and is compatible with theindustry-standard 80C51 instruction set and pinout. The on-chip Flash allows the

program memory to be reprogrammed in-system or by a conventional nonvolatile

memory pro-grammer. By combining a versatile 8-bit CPU with in-system programmable

Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller, whichprovides a highly flexible and cost-effective solution to many, embedded control

applications. The AT89S52 provides the following standard features: 8K bytes of Flash,


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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 logicfor operation down to zero frequency and supports two software selectable power saving

modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial

port, and interrupt system to continue functioning. The Power-down mode saves theRAM con-tents but freezes the oscillator, disabling all other chip functions until the next

interrupt


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The hardware is driven by a set of program instructions, or software. Once familiar with

hardware and software, the user can then apply the microcontroller to the problemseasily.

The pin diagram of the 8051 shows all of the input/output pins

microcontrollers:

The following are some of the capabilities of 8051 microcontroller.

Internal ROM and RAM

I/O ports with programmable pins

Timers and counters


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Serial data communication

The 8051 architecture consists of these specific features:

16 bit PC &data pointer (DPTR)

8 bit program status word (PSW)

8 bit stack pointer (SP)

Internal ROM 4k

Internal RAM of 128 bytes.

4 register banks, each containing 8 registers

80 bits of general purpose data memory

32 input/output pins arranged as four 8 bit ports: P0-P3

Two 16 bit timer/counters: T0-T1

Two external and three internal interrupt sour

Oscillator and clock circuits.

BLOCK DIAGRAM:

8051


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Level Converter

SMS

IR Sensor

Fire Sensor

LPG Gas Sensor

PORT1

BUY THIS PROJECT NOW

CALL US AT +91-9013296909

Email us at - [email protected]

Visit Us at www.IndianEngineer.in


10/22

Tags: MICROCONTROLLER BASED MULTI STORY CAR PARKING SYSTEM Comment

Cell Phone Operated land Rover( landrover)

Filed under: Cell Phone Operated Land Rover, Circuti Ideas, Uncategorized byIndianEngineer Leave a comment

May 12, 2010

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 andcapabilities 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.

PROJECT OVERVIEW

Cell phone operated land Rover,Robot,Moving Vehicle.circuit

In this project, the robot is controlled by a mobile phone that makes a call to

the mobile phone attached to the robot. In the course of a call, if any button

is pressed,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.
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The robot perceives this DTMF tone with the help of the phone stacked in the

robot. The received tone is processed by the ATmega16 microcontroller with

the help of DTMF decoder MT8870. The decoder decodes the DTMF tone into

its equivalent binary digit and this binary number is sent to the

microcontroller.The microcontroller is preprogrammed 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 signaling is used fr telephone signaling over the line in the voice-

frequency band to the call switching centre. The version ofDTMF used for

telephone tone dialing is known as Touch-Tone.DTMF assigns a specific

frequency (consisting of two separatetones) to each key so that it can easilybe 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. The

tones and assignments in a DTMF system are shown in Table I.

SCEMATIC OF CELLPHONE OPERATED LANDROVER

Cell phone operated land rover circuit,robot,moving vehicle

CIRCUIT DESCRIPTION

Fig. 1 shows the block diagram of the microcontroller-based mobile

phoneoperated land rover. The important components of this rover are a

DTMF decoder, microcontroller and motor driver. An MT8870 series DTMF

decoder is used here. All types of the MT8870 series use digital counting

techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code

output. The built-in dial tone rejection circuit eliminates the need for pre-

filtering. When the input signal given at pin 2 (IN-) in single-ended input

configuration is recognised to be effective, the correct 4-bit decode signal of

the DTMF tone is transferred to Q1 (pin 11) through Q4 (pin 14) outputs.
http://projectsworld.files.wordpress.com/2010/05/landrover_schematic_atmega16.jpg


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Table II shows the DTMF data output table of MT8870. Q1 through Q4 outputs

of the DTMF decoder (IC1) are connected to port pins PA0 through PA3 of

ATmega16 microcontroller (IC2) after inversion by N1 through

N4,respectively. The ATmega16 is a low-power, 8-bit, CMOS microcontroller

based on the AVR enhanced RISC architecture. It provides the following

features: 16 kB of in-system programmable Flash program memory with

read-while-write capabilities, 512 bytes of EEPROM, 1kB SRAM, 32 general-

purpose input/output (I/O) lines and 32 general-purpose working registers. All

the 32 registers re directly connected to the arithmetic logic unit, allowing

two independent registers to be accessed in one single instruction executed

in one clock cycle. The resulting architecture is more code-efficient. Outputs

from port pins PD0 through PD3 and PD7 of the microcontroller are fed to

inputs IN1 through IN4 and enable pins (EN1 and EN2) of motor driver L293D,espectively, to drive two geared DC motors. Switch S1 is used for manual

reset. The microcontroller output is not sufficient to drive the DC motors, so

current drivers are required for motor rotation. The L293D is a quad, high-

current, half-H driver designed to provide bidirectional drive currents of up to

600 mA at voltages from 4.5V to 36V. It makes it easier to drive the DC

motors. The L293D consists of four drivers. Pin IN1 through IN4 and OUT1

through OUT4 are input and output pins, respectively, of driver 1 through

driver 4. Drivers 1 and 2, and drivers 3 and 4 are enabled by enable pin 1

(EN1) and pin 9 (EN2), respectively. When enable input EN1 (pin 1) is high,

drivers 1 and 2 are enabled and the outputs corresponding to their inputs are

active. Similarly, enable input EN2 (pin 9) enables drivers 3 and 4. An actual-

size, single-side PCB for cellphone-operated land rover is shown in Fig. 4 and

its component layout in Fig. 5.

PCB LAYOUT FOR CELLPHONE OPERATED LANDROVER

pcb design free

SOFTWARE DESCRIPTION
http://projectsworld.files.wordpress.com/2010/05/landrover_dtmf_pcblayout-1.jpg


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The software is written in C language and compiled using CodeVision AVR

C compiler. The source program is ed into hex code by the compiler. Burn

this hex code into ATmega16 AVR microcontroller.The source program is well

commented and easy to understand. First include the register name defined

specifically for ATmega16 and also declare the variable. Set port A as the

input and port D as the output. The program

will run forever by using while loop. Under while loop, read port A and test

the received input using switch statement. The corresponding data will

output at port D after testing of the received data.

WORKING

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 iskept in auto answer mode. (If the mobile does not have the auto answering

facility, receive the call by OK key on the rover-connected mobile and then

made it in hands-free mode.) So after a ring, the cellphone accepts the call.

Now you may press any button on your mobile to perform actions as listed in

Table III. The DTMF tones thus produced are received by the cellphone in the

robot. These tones are fed to the circuit by the headset of the

cellphone. The MT8870 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 (as per Table

III). Similarly, motors M1 and M2 move for left turn, right turn, backward

motion and stop condition as per Table III.

CONSTRUCTION


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Cellphone operated land rover project

When constructing any robot, one major mechanical constraint is the number

there a two-wheel drive or a four-wheel ive. Though four-wheel drive is more

complex than two-wheel drive, it provides more torque and good control.

Two-wheel drive, on the other hand, is very easy to construct. Top view of a

four-wheel-driven land rover is shown in Fig. 3. The chassis used in this model

is a 1018cm2 sheet made up of parax. Motors are fixed to the bottom of

this sheet and the circuit is affixed firmly on top of the sheet. A cellphone is

also mounted on the sheet as shown in the picture. In the four-wheel drive

system, the two motors on a side are controlled in parallel. So a single L293D

driver IC can drive the rover. For this robot, beads affixed with glue act as

support wheels.

PROGRAM FOR CELLPHONE OPERATED LANDROVER

Source program:

Robit.c

#include

void main(void)

{

unsigned int k, h;

DDRA=000;

DDRD=0XFF;

while (1)

{

k =~PINA;

h=k & 0x0F;

switch (h)
http://projectsworld.files.wordpress.com/2010/05/cellphone_operated_landrover.jpg


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{

case 002: //if I/P is 002

{

PORTD=089;//O/P 089 ie Forward

break;

}


{

PORTD=086; //O/P 086 ie Backward

break;

}

case 004:

{PORTD=085; // Left turn

break;

case 006:

{

PORTD=0x8A; // Right turn

break;

}

case 005:

{

PORTD=000; // Stop

break;

}

}

}

}

CLICK HERE TO GO BACK TO MAIN LIST

Electronic VotingMachine Filed under: Uncategorized by IndianEngineer Leave a comment

May 12, 2010

BLOCK DIAGRAM OF

ELECTRONICS VOTING MACHINE WITH BALLOT UNIT
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16/22

Electronic Voting Maching Circuit ckt Diagram Project

Discription 2X16 LCD DISPLY USED

4X3 KEYBORD USED FOR PASSWORD ENTRY

WHEN CONTROLLER IS CONNECTED TO BALLOT UNIT AND WHEN BUTTON IS

PRESSED ON BALLOT UNIT RESPECTIVE LRD GLOWS AND SERIALLY

COMMUNICATED TO CONTROLLER TO UPGRADE THE DATA IN EEPROM AS

WELL AS DISPLAYED ONLCD.

WHEN YOU WANT TO KNOW THE RESULT OF ELECTION CONNECT THE

CONTROLER TO PC ANDBY PRESSING THE KEY YOU CAN KNOW THE RESULT

ON MONITOR OF PC AS WELL AS SAVE THE FILE IN PC .

Click Here to Go Back To Complete list of Projects

Electronic voting Maching Project, Electronic Voting Maching Circuit,

Electronic Voting Maching Free Project, Microcontroller based Electronic

Voting Machine.

Cell Phone Operated land Rover ( landrover)

Filed under: Cell Phone Operated Land Rover, Circuti Ideas, Uncategorized byIndianEngineer Leave a comment

May 12, 2010

INTRODUCTION

Conventionally, wireless-controlled robots use RF circuits,which have the

drawbacks of limited working range, limited frequency range and limited

control. Use ofa mobile phone for robotic control can overcome these
http://projectsworld.files.wordpress.com/2010/05/schematic_electronic_voting_machine.jpghttp://indianengineer.wordpress.com/2010/05/02/microcontroller-based-projects-2/http://projectsworld.wordpress.com/2010/05/12/cell-phone-operated-land-rover-landrover/http://projectsworld.wordpress.com/2010/05/12/cell-phone-operated-land-rover-landrover/http://en.wordpress.com/tag/cell-phone-operated-land-rover/http://en.wordpress.com/tag/circuti-ideas/http://projectsworld.wordpress.com/category/uncategorized/http://projectsworld.wordpress.com/2010/05/12/cell-phone-operated-land-rover-landrover/#respond


17/22

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.

PROJECT OVERVIEW

Cell phone operated land Rover,Robot,Moving Vehicle.circuit

In this project, the robot is controlled by a mobile phone that makes a call to

the mobile phone attached to the robot. In the course of a call, if any button

is pressed,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 ATmega16 microcontroller with

the help of DTMF decoder MT8870. The decoder decodes the DTMF tone into

its equivalent binary digit and this binary number is sent to the

microcontroller.The microcontroller is preprogrammed 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 signaling is used fr telephone signaling over the line in the voice-

frequency band to the call switching centre. The version of DTMF used for


18/22

telephone tone dialing is known as Touch-Tone.DTMF assigns a specific

frequency (consisting of two separatetones) 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. The

tones and assignments in a DTMF system are shown in Table I.

SCEMATIC OF CELLPHONE OPERATED LANDROVER

Cell phone operated land rover circuit,robot,moving vehicle

CIRCUIT DESCRIPTION

Fig. 1 shows the block diagram of the microcontroller-based mobile

phoneoperated land rover. The important components of this rover are a

DTMF decoder, microcontroller and motor driver. An MT8870 series DTMF

decoder is used here. All types of the MT8870 series use digital counting

techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code

output. The built-in dial tone rejection circuit eliminates the need for pre-filtering. When the input signal given at pin 2 (IN-) in single-ended input

configuration is recognised to be effective, the correct 4-bit decode signal of

the DTMF tone is transferred to Q1 (pin 11) through Q4 (pin 14) outputs.

Table II shows the DTMF data output table of MT8870. Q1 through Q4 outputs

of the DTMF decoder (IC1) are connected to port pins PA0 through PA3 of

ATmega16 microcontroller (IC2) after inversion by N1 through

N4,respectively. The ATmega16 is a low-power, 8-bit, CMOS microcontroller

based on the AVR enhanced RISC architecture. It provides the following

features: 16 kB of in-system programmable Flash program memory with

read-while-write capabilities, 512 bytes of EEPROM, 1kB SRAM, 32 general-

purpose input/output (I/O) lines and 32 general-purpose working registers. All

the 32 registers re directly connected to the arithmetic logic unit, allowing

two independent registers to be accessed in one single instruction executed

in one clock cycle. The resulting architecture is more code-efficient. Outputs
http://projectsworld.files.wordpress.com/2010/05/landrover_schematic_atmega16.jpg


19/22

from port pins PD0 through PD3 and PD7 of the microcontroller are fed to

inputs IN1 through IN4 and enable pins (EN1 and EN2) of motor driver L293D,

espectively, to drive two geared DC motors. Switch S1 is used for manual

reset. The microcontroller output is not sufficient to drive the DC motors, so

current drivers are required for motor rotation. The L293D is a quad, high-

current, half-H driver designed to provide bidirectional drive currents of up to

600 mA at voltages from 4.5V to 36V. It makes it easier to drive the DC

motors. The L293D consists of four drivers. Pin IN1 through IN4 and OUT1

through OUT4 are input and output pins, respectively, of driver 1 through

driver 4. Drivers 1 and 2, and drivers 3 and 4 are enabled by enable pin 1

(EN1) and pin 9 (EN2), respectively. When enable input EN1 (pin 1) is high,

drivers 1 and 2 are enabled and the outputs corresponding to their inputs are

active. Similarly, enable input EN2 (pin 9) enables drivers 3 and 4. An actual-size, single-side PCB for cellphone-operated land rover is shown in Fig. 4 and

its component layout in Fig. 5.

PCB LAYOUT FOR CELLPHONE OPERATED LANDROVER

pcb design free

SOFTWARE DESCRIPTION

The software is written in C language and compiled using CodeVision AVR

C compiler. The source program is ed into hex code by the compiler. Burn

this hex code into ATmega16 AVR microcontroller.The source program is well

commented and easy to understand. First include the register name defined

specifically for ATmega16 and also declare the variable. Set port A as the

input and port D as the output. The program

will run forever by using while loop. Under while loop, read port A and test

the received input using switch statement. The corresponding data will

output at port D after testing of the received data.

WORKING

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
http://projectsworld.files.wordpress.com/2010/05/landrover_dtmf_pcblayout-1.jpg


20/22

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 rover-connected mobile and then

made it in hands-free mode.) So after a ring, the cellphone accepts the call.

Now you may press any button on your mobile to perform actions as listed in

Table III. The DTMF tones thus produced are received by the cellphone in the

robot. These tones are fed to the circuit by the headset of the

cellphone. The MT8870 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). Portpins PD0 and PD3 drive motors M1 and M2 in forward direction (as per Table

III). Similarly, motors M1 and M2 move for left turn, right turn, backward

motion and stop condition as per Table III.

CONSTRUCTION

Cellphone operated land rover project

When constructing any robot, one major mechanical constraint is the number

there a two-wheel drive or a four-wheel ive. Though four-wheel drive is more

complex than two-wheel drive, it provides more torque and good control.

Two-wheel drive, on the other hand, is very easy to construct. Top view of a

four-wheel-driven land rover is shown in Fig. 3. The chassis used in this model

is a 1018cm2 sheet made up of parax. Motors are fixed to the bottom of

this sheet and the circuit is affixed firmly on top of the sheet. A cellphone is

also mounted on the sheet as shown in the picture. In the four-wheel drive
http://projectsworld.files.wordpress.com/2010/05/cellphone_operated_landrover.jpg


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system, the two motors on a side are controlled in parallel. So a single L293D

driver IC can drive the rover. For this robot, beads affixed with glue act as

support wheels.

PROGRAM FOR CELLPHONE OPERATED LANDROVER

Source program:

Robit.c

#include

void main(void)

{

unsigned int k, h;

DDRA=000;

DDRD=0XFF;

while (1){

k =~PINA;

h=k & 0x0F;

switch (h)

{


{

PORTD=089;//O/P 089 ie Forward

break;

}


{

PORTD=086; //O/P 086 ie Backward

break;

}

case 004:

{PORTD=085; // Left turn

break;

case 006:

{

PORTD=0x8A; // Right turn

break;


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}

case 005:

{

PORTD=000; // Stop

break;

}

}

}

}

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