[attachment=2733]


CHAPTER 1
INTRODUCTION
Surveillance, Espionage or spying involves individual obtaining information that is considered secret or confidential without the permission of the holder of the information. Spying area in military ground where enemy stay can be took before taking any action.
A robot is a virtual or mechanical artificial agent. In practice, it is usually an electro mechanical system which, by its appearance or movements, conveys a sense that it has intent or agency of its own.
Our aim in building this project is to create a wireless controlled robotic vehicle which can be operated through a range of 100 meters using 433 MHz RF transmitter and receiver. This can also sense the obstacles on its way to maneuvering its path by using Infrared sensors. This vehicle is equipped with a metal detector can detect any land mine on its way, and wireless camera which will transmit the live pictures and videos remotely.
This unit is helpful and useful for surveillance of an area in defence grounds for enemy, spying purpose where the human reach is not recommended or avoided. The unit is small handy portable and can reach places easily.
1.1 MAIN FEATURES OF THE PROJECT
1. Effective in implementation
2. Low power consumption and compact size.
3. Long control range due the usage of RF devices.
4. Robot monitored from a remote area (no need of 'line-of-sightâ„¢ arrangement).
5. Maneuvering its path avoiding obstacles by own
6. Land mine detection
7. Wireless video surveillance
1.2 THE SIMPLIFIED BLOCK DIAGRAM
Fig. 1.1 ROBOT
Fig. 1.2 REMOTE
CHAPTER 2
BLOCK DIAGRAM DESCRIPTION
The DEFENCE SURVIELLIANCE ROBOT is better understood by explaining the block diagram units in two separate sections Viz.
1. Robot end (Receiver)
2. Remote (Transmitter)
2.1 ROBOT END (RECEIVER).
Fig. 2.1 BLOCKS DIAGRAM OF RECEIVER
In the above block diagram we are used 89S52 microcontrollers which are a 40 Pin 8-bit, 32 I/O lines. This is the brain of the whole circuit. The robot system consists of RF receiver 433MHZ to receive the commands from the remote. Here the received data
will be in RF signal where it is converted to digital data by RF receiver and input to HT648 decoder which decodes(demux) the digital data and input to microcontroller port1.
And astable multivibrator, to generate 38 kHz square wave for the IR transmitter and
monostable multivibrator to receive the signal from the TSOP to sense the obstacle on its way and IC ULN2803 driver with an electromagnetic relay to control the DC motor .The port 2 of microcontroller is used to control the direction(CLK/ANTCLK) and ON/OFF condition of two DC motor. Port 0 is used to receive signal from 555 monostable circuit which is triggered by TSOP 1738.a brief description of all the blocks explained below.
2.1.1 Microcontroller AT 89S52
The micro controller used here is 89S52 is a low power, high performance CMOS 8-bit micro controller with 8K bytes of programmable flash memory. The 89S52 is the family of Intel 8051. It is powerful micro controller which provides high flexibility and cost efficient solutions to many embedded controller application.
This is like brain of the robot which operates the robot according to the user command. 40 pin Integrated Circuit and 8bit operation which receives the signals from 4 ports. It is programmed so to operate by receiving signal from RF receiver circuit through port 1.0 to port 1.4, and from 555 monostable circuit which is triggered by TSOP 1738 IR sensor through port 0.0 to port 0.2.and drives the motor through ULN2803 using port 2.0 to port 2.3.
2.1.2 ULN 2803
This is the IC with the standard Darlington arrays. The outputs are capable of sinking 500 mA and will withstand at least 50 V in the off state. Outputs may be paralleled for higher load current capability. These Darlington arrays are furnished in 18-pin dual in-line plastic packages. Here this is used to drive the relays.
2.1.3 Relay
A relay is an electrical switch that opens and closes under the control of another electrical circuit. In the original form, the switch is operated by an electromagnet to open or close one or many sets of contacts. Here relay is driven by ULN2803 from microcontroller. This is used to switch the DC motor to ON/OFF or to rotate in different directions clock wise and anti clockwise.
2.1.4 Gear DC Motor
A DC motor works by converting electric power into mechanical work. This is accomplished by forcing current through a coil and producing a magnetic field that spins the motor. Gear DC Motor is used to drive the robot which is connect to wheel of the robot this motor is called as gear motor because this has a specific number of RPM based on the combination of gears connected to the shaft of dc motor.
2.1.5 IR Sensors
The sensor used is the TSOP1738. It only senses the signal of frequency 38 kHz. This sensor is used to avoid the reception of signals from other sources. The 38 kHz signal is only used by TSOP1738 so, it can be horizontally mounted. It senses the reflected IR rays from 38 kHz IR source to detect any obstacle on its way.
2.1.6 555 Triggering Circuit
555 timer circuits are constructed in monostable mode, which in turn triggered by TSOP1738. This in turn produces the high frequency pulse which is input to microcontroller port 0.
2.1.7 RF Receiver
433 MHz RF receiver is used having 8 pin. This receives the RF signal transmitted and converts it in to digital data signal. And these have a range of up to 100 meters with no line of sight.
2.1.8 Decoder HT 648
These are 318 series of decoders receives serial address and data from that series of encoders that are transmitted by a carrier using an RF. It then compares the serial input data twice continuously with its local address. If no errors or unmatched codes are encountered, the input data codes are decoded and then transferred to the output pins.
2.1.9 Battery
Rechargeable Lead acid battery is used. This is the main power supply for the whole robot provides 12 Volts and a max current of up to 1.2A.Which is further regulated to 5volts for digital circuit operation. A charger circuitry is used to charge the battery.
2.1.10 IR Emitters
A 555 timer is used to generate the signal of frequency 38 kHz. The 555 timer is configured in astable mode. The output of this timer is given to an IR emitter. This signal is emitted by the emitter which is mounted horizontally at the front of the robot.
2.1.11 Mine Detector
The mine detector is used to detect the land mines buried beneath the land. It detects the mine on its way by indicating a buzzer sound.
2.1.12 Wireless Camera
A camera is a device that records images, either as a still photograph or as moving images known as videos. This is used in the robot to take the video surveillance of the area. And it is transmitted using a carrier signal. On the receiving end it is converted to video signal. It has a range of 70-100Mts with no line of sight.
2.2 REMOTE (TRANSMITTER)
Fig. 2.2 BLOCK DIAGRAM OF TRANSMITTER
2.2.1 Keypad
By using this we are giving command to the robot this is in the remote side this has 5 keys with different operations
2.2.2 Encoder HT 640
They are capable of encoding 18 bits of information which consists of 10 address bits and 8 data bits. The programmable address/data is transmitted together with the header bits via an RF Transmitter.
2.2.3 RF Transmitter
433 MHz RF transmitter is used having 4 pin. This transmits the RF signal by using ASK. The range is up to 100 meters with no line of sight.
CHAPTER 3
CIRCUIT DIAGRAM AND DESCRIPTION
Depend upon the circuit diagram this system is divided into following stages:
1. Main board circuit (Microcontroller).
2. RF Receiver.
3. RF Transmitter with keypad.
4. 555 Astable (38 kHz IR emitter).
5. 555 monostable (IR Trigger).
6. Mine Detector.
3.1 MAIN BOARD CIRCUIT
Fig. 3.1 MAIN BOARD CIRCUIT
Figure 3.1 shows the circuit diagram that Consists of Atmel 89S52 microcontroller with relay driver. Port1 is connected RF receiver circuit so this port is used as input port. Port 0 is connected to output pin of 555 monostable circuit, this port is also used as input port. Port 2 is used as output port which is connected to ULN2803 to drive four relay that control dc motor.7805 regulator used to give the regulated output to 5 volts. It is a 3 Pin device.Pin1 is input, Pin2 is GND and PIn3 is output 5volts.The operation range for 7805 is 6volt-7volt, which gives regulated output 5volts. An 11.0592MHZ crystal is connected to Pin 18 & Pin19 of microcontroller. A pair of 33pf ceramic disk capacitor is connected to crystal. Another lead of the capacitor is connected to GND. To avoid any harmonics generated during the time of oscillation and to maintain sustain oscillation for the perfect operation of microcontroller 10k register is connected to GND, another point is connected to PIn9 which is a reset pin 10muf capacitor is connected to Pin9 and other lead is connected to vcc. A high signal on this Pin makes the controller to reset. Pin 31 is connected to vcc which is an EA/VPP. When high on this Pin makes the controller to access data from internal memory. Low on this makes the access the data from external memory. Vpp is voltage pulse for programming used during the down loading HEX file to the microcontroller.
Also 10K sip is used as pull up resistor, where it will not allows port to enter the tristate. This is to have constant voltage. Microcontroller controls the relay using driver circuit Output data of port 2 is given to ULN2803 IC which is of 8 bit. If the active low input is given relay will ON else it OFF. Then according to the inputs to relay the corresponding actions takes.
The movements of gear motors can be achieved as follows by switching the relays through ULN 2803.
1. Stop: All four relays OFF
2. Forward direction: when 1st, 4th relay ON; 2nd, 3rd relay OFF.
3. Right direction: when 1st, 3rd relay ON; 2nd, 4th relay OFF.
4. Left direction: when 2nd, 4th relay ON. 1st,3rd relay OFF
5. Reverse direction: when 2nd, 3rd relay ON. 1st, 4th relay OFF.

3.1.1 PIN/PORT Connections
Of the four ports of microcontroller, three ports are used for the robot .Port 1 and Port 0 is used as input port while port 2 is the output port. The basic connections like reset, power supply and crystal oscillator are given to their respective pins. The relay, sensor and RF connections to the respective ports are listed in the table
PORT NUMBER BIT CONNECTION
P-0
0 IR SENSOR RIGHT
1 IR SENSOR CENTRE
2 IR SENSOR LEFT
3 NO CONNECTION
4 NO CONNECTION
5 NO CONNECTION
6 NO CONNECTION
7 NO CONNECTION
P-1
0 RF DATA OUT 1
1 RF DATA OUT 2
2 RF DATA OUT 3
3 RF DATA OUT 4
4 RF DATA OUT 5
5 NO CONNECTION
6 NO CONNECTION
7 NO CONNECTION
Table 3.1
PORT NUMBER BIT CONNECTION
P-2
0 RELAY 1
1 RELAY 2
2 RELAY 3
3 RELAY 4
4 NO CONNECTION
5 NO CONNECTION
6 NO CONNECTION
7 NO CONNECTION
P-3
0 NO CONNECTION
1 NO CONNECTION
2 NO CONNECTION
3 NO CONNECTION
4 NO CONNECTION
5 NO CONNECTION
6 NO CONNECTION
7 NO CONNECTION
Table 3.2
3.2 RF RECEIVER CIRCUIT
Fig. 3.2 RF RECIEVER CIRCUIT
This is the radio frequency receiver circuit. The circuit contains mainly two components RF receiver module which is embedded circuit, and decoder IC HT648. Data output from the RF module is given to pin 9 of HT648 which is data in of decoder. The decoded data output from the HT6498 is given to port 1 of microcontroller 89S52.
3.3 RF TRANSMITTER AND KEYPAD CIRCUIT
Fig. 3.3 RF TRANSMITTER CIRCUIT
This is the radio frequency Transmitter circuit. The circuit contains mainly two components RF transmitter module which is embedded circuit, and encoder IC HT640. Keypad is connected to 5 data pins of encoder IC when key is pressed data pin gets logic high signal that is vcc +5v.So this 8 bit data is encoded in to single data and transmitted via RF Tx module as radio frequency signal.
3.4 555 ASTABLE (38 KHZ IR EMITTER) CIRCUIT
Fig. 3.4 555 ASTABLE CIRCUIT
A 555 timer is used to generate the signal of frequency 38 kHz. The 555 timer is configured in astable mode. The output of this timer is given to an IR LED as emitter. This signal is emitted by the emitter which is mounted horizontally at the front of the robot. Here we are using three IR LED connected parallel to the output of astable multi vibrator circuit. They are mounted in left, right and centre of robot front.
The astable multivibrator is a 555 timer 8 pin device. Pin 4 is reset, Pin 5 is threshold connected to 0.01muf capacitor another 0.01muf capacitor is connected to pin 2 and GND. Pin 6 & 7 is connected to designed value resistor & capacitor to generate the desired frequency. Here we are used to generate 38 kHz square wave Pin3 of 555 timer is connected to BC547 transistor base to drive the LED without any loss. BC-547 is a 3Pin device collector, emitter & base and is a NPN transistor. The collector pin is connected to IR LED through 3.9k resistor. To avoid the max current flow this can damage the device. IR LED is a 2 pin device anode and cathode commonly used in remote controls.
3.5 555 MONOSTABLE WITH TSOP1738 CIRCUIT
Fig. 3.5 555 MONOSTABLE CIRCUIT
The sensor used is the TSOP1738. It only senses the signal of frequency 38 kHz. This sensor is used to avoid the reception of signals from other sources. The 38 kHz signal is only used by TSOP1738 so, it can be horizontally mounted.
Monostable vibrator is an 8 pin 555 timer Ic.Pin1 is GND, Pin2 is trigger, Pin3 output, Pin4 reset, Pin5 threshold, Pin6 & 7 is used to design the ON/OFF time and Pin8 is vcc. The output pin of TSOP1738 is connected to trigger pin of monostable circuit whenever TSOP senses the 38 KHz IR signal sensor output pin goes low. This triggers the 555 circuit which in turn generates a high frequency pulse at pin 3. This is the input for microcontroller port 0.
3.6 MINE DETECTOR
Fig. 3.6 MINE DETECTOR CIRCUIT
Fig. 3.7 BLOCK DIAGRAM OF MINE DETECTOR
This circuit most useful for safety checking. To check any land mines on its way.
.
The Mine detector can be used to detect the land mines composed of metallic substance. It uses a sensing coil. This coil should be kept near metallic objects for detection. Input of circuit is a weak colpittâ„¢s R.F. range oscillator. Sensing coil forms parts of tuned oscillator.
When coil is brought near a metallic object magnetic energy is absorbed and oscillator fails to work. Then final transistor conducts and buzzer is activated. Use a 9 volts battery. After connecting battery, adjust the 4.7K preset till circuit just stops sounding
3.7 COMPONENTS USED
SEMICONDUCTORS SPECIFICATION
Microcontroller 89S52 1
Driver ULN 2803 1
Timer 555 4
Encoder HT 640 1
Decoder HT 648 1
Transistors BC 547 5
Diodes IN 4148 4
RF Tx Rx Module 433 MHz 1 pair
Regulator 7805 1
IR Sensor TSOP 1738 3
IR LED 3
LED
PASSIVE COMPONENTS
Resistors
Capacitors
Relay
MISCELLANIOUS
Battery 12V, 1.2A and 9V
Camera video and audio
DC Motor
Buzzer
Connectors
Switches SPDT, NO switch
Coil
CHAPTER 4
HARDWARE DESCRIPTION
4.1 MICROCONTROLLER AT89S52
Fig. 4.1 PIN DIAGRAM 89S52
4.1.1 Features of AT 89S52
¢ Compatible with MCS®-51 Products
¢ 8K Bytes of In-System Programmable (ISP) Flash Memory
“ Endurance: 10,000 Write/Erase Cycles
¢ 4.0V to 5.5V Operating Range
¢ Fully Static Operation: 0 Hz to 33 MHz
¢ Three-level Program Memory Lock
¢ 256 x 8-bit Internal RAM
¢ 32 Programmable I/O Lines
¢ Three 16-bit Timer/Counters
¢ Eight Interrupt Sources
¢ Full Duplex UART Serial Channel
¢ Low-power Idle and Power-down Modes
¢ Interrupt Recovery from Power-down Mode
¢ Watchdog Timer
¢ Dual Data Pointer
¢ Power-off Flag
¢ Fast Programming Time
¢ Flexible ISP Programming (Byte and Page Mode)
¢ Green (Pb/Halide-free) Packaging Option
4.1.2 Description
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 Atmelâ„¢s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. 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. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.
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. In this mode, P0 has internal pull-ups. Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pull-ups are required during program verification.
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. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the following table. Port 1 also receives the low-order address bytes during Flash programming and verification.
Table 4.1
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 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memories that use 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memories that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.
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. Port 3 receives some control signals for Flash programming and verification. Port 3 also serves the functions of various special features of the AT89S52, as shown in the following table.
Table 4.2
RST
Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives high for 98 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.
ALE/PROG
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. Note, however, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.
PSEN
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.
EA/VPP
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. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming.
XTAL1
Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
XTAL2
Output from the inverting oscillator amplifier.
4.2 UNIPOLAR MOTOR DRIVER ULN 2803
Fig. 4.2 PIN DIAGRAM ULN 2803
Here ULN2803 is a unipolar motor driver featuring continuous load current ratings to 500mA for each of the drivers, the Series ULN2803 High-voltage; High-current Darlington arrays are ideally suited for interfacing between low-level logic circuitry and multiple peripheral power loads. Typical power loads totalling over 260 W (350 mA x 8, 95 V) Can be controlled at an appropriate duty cycle depending on ambient Temperature and number of drivers turned on simultaneously. Typical loads include relays, solenoids, stepping motors, magnetic print hammers, multiplexed LED and incandescent displays, and heaters.
The device feature open-collector outputs with integral clamp diodes. Have series input resistors selected for operation directly with 5 V TTL or CMOS. This device will handle numerous interface needs particularly those beyond the capabilities of standard logic buffers.
The ULN2803A are the standard Darlington arrays. The outputs are capable of sinking 500 mA and will withstand at least 50 V in the off state. Outputs may be paralleled for higher load current capability.
These Darlington arrays are furnished in 18-pin dual in-line plastic packages (suffix ËœAâ„¢) or 18-lead small-outline plastic packages (suffix ËœLWâ„¢). All devices are pinned with outputs opposite inputs to facilitate ease of circuit board layout. Prefix ËœULNâ„¢ devices are rated for operation over the temperature range of -20o C to +85o C
4.2.1 Features
¢ TTL, DTL, PMOS, or CMOS Compatible Inputs.
¢ Output Current to 500 mA.
¢ Output Voltage to 95 V.
¢ Transient-Protected Outputs.
¢ Dual In-Line Package or Wide-Body Small-Outline Package.
4.3 RELAY
A relay is an electromagnetic switch. In other words it is activated when a current is applied to it. Normally a relay is used in a circuit as a type of switch (as you will see below). There are different types of relays and they operate at different voltages. When you build your circuit you need to consider the voltage that will trigger it.
Fig 4.3 RELAY
The main part of a relay is the coil at the centre. A small current flowing through the coil in the relay creates a magnetic field that pulls one switch contact against or away from another. Putting it simply, when current is applied to the contacts at one side of the relay the coil allows the contacts at the other side to work. Usually relays are used to turn on a second circuit. The first circuit activates the relay which then Ëœturns onâ„¢ the second circuit.
There are few advantages The contacts can be either Normally Open (NO), Normally Close (NC) or change-over (CO) contacts. In my project I used the normally-open contacts as it will rotate DC motor when the relay is activated; the circuit is disconnected when the relay is inactive. It is also called Form A contact or make contact. Form A contact is ideal for applications that require to switch a high current power source from a remote device. Relays have a lot of useful applications and among the usage are to control a high-current circuit with a low-current signal, as in the starter solenoid of an automobile and also to detect and isolate faults on transmission and distribution lines by opening and closing circuit breakers.
There are few advantages of relays such as the complete electrical isolation safety by ensuring that high voltages and currents cannot appear where they should not be. Also, relays come in all shapes and sizes for different applications and they have various switch contact configurations. Lastly it is easy to tell when a relay is operating as we can hear a click as the relay switches on and off and we can sometimes see the contacts moving. The disadvantages of relays are at their parts as it can wear out as the switch contacts become dirty due to high voltages and currents sparks between the contacts. Also they cannot be switched on and off at high speed because they have a slow response and the switch contacts will rapidly wear out due to the sparking.
4.4 RF TRANSMITTER AND RECEIVER MODULE
4.4.1 Transmitter
1 2 3 4
Fig. 4.4 RF TRANSMITTER
1. GND
2. DATA IN
3. VCC
4. ANTENNA
A transmitter is a circuit with an output sent through the air by light, sound or electromagnetic waves at a specific frequency. Radio frequency (RF) transmitters are widely used in radio frequency communication systems. The function of a radio frequency (RF) transmitter is to modulate, up convert and amplify signals for transmission into free space. The radio frequency transceiver modules can use a wide range of input voltages; as a result, transmitter voltage varies by module specification. Higher radio frequency module voltages usually result in greater transmission distances. In this case, a wireless transmitter module shown above is used, where the launch frequency for it is at 433MHz. This transmitter module is stable and reliable, high quality and low cost features.
Particularly suitable for variety of small volume application of wireless remote control alarm and MCU for short-range wireless data transmission with a wide range of voltage (3V-12V) and low power characteristic (10mW). Above is the transmitter module. The transmitter module sends an electromagnetic signal that encodes the information, whereas the receiver accepts the signal and decodes it.
Features
¢ Working voltage: 3v-12v
¢ Working current: 10-15ma
¢ Frequency:433mhz
¢ Range: 100 mts
¢ Transport speed:4800kbps
¢ Encoder IC: HT 640
4.4.2 Receiver
Fig.4.5 RF RECEIVER
PIN Connections
1- ANT 5-VCC
2- GND 6-DATA
3- GND 7-DATA
4- VCC 8-GND
A receiver is a circuit capable of accepting and processing light, sound or electromagnetic waves of a specific range. RF receivers are electronic devices that separate radio signals from one another and convert specific signals into audio, video, or data formats. RF receivers use an antenna to receive transmitted radio signals and a tuner to separate a specific signal from all of the other signals that the antenna receives. In this type of receiver, which is the wireless radio super regeneration receiver module, the
433MHz radio frequency signal sent by the transmitter module is received and the
incoming data extracted from the signal. The extracted data is then sent out in serial format to the decoder board. Above is the receiver module that is used in this project. This low cost RF receiver module can be used to receive RF signal from any 433MHz transmitter. Super regeneration design ensures the sensitivity to week signal. The key benefits of this device are the low power consumption easy to integrate (V+, GND and DATA) and also it is so small in dimension.
Fig. 4.6 RF RECEIVER MODULE
Features
¢ Working voltage: 5v
¢ Working current: 0.5-0.8ma
¢ Frequency:433mhz
¢ Range: 100 mts
¢ Transport speed:4800kbps
¢ Decoder IC:HT 648
Applications
Burglar alarm system
Smoke and fire alarm system
Garage door controllers
Car door controllers
Car alarm system
Security system
Cordless telephones
Other remote control systems
4.5 ENCODER HT 640
An encoder is a device used to change a signal or data into a code. The code may serve any of a number of purposes such as compressing information for transmission or storage, encrypting or adding redundancies to the input code, or translating from one code to another. An encoder also a circuit in which a code or signal presented in one format can be changed to a format compatible with circuitry it interfaces with. As for my project, the encoder HT 640 is the Holtek 318 encoders which are series of CMOS LSIs for remote control system applications. They are capable of encoding 18 bits of information which consists of N address bits and 18N data bits. Each address or data input is externally
trinary programmable if bonded out. It is otherwise set floating internally. Various packages of 318 encoders offer flexible combinations of programmable address or data to meet various application needs. The programmable address or data is transmitted together with the header bits via an RF or an infrared transmission. The capability to select a TE trigger type or a DATA trigger type further enhances the application flexibility of the 318 series of encoders.
The best features of using this encoder are because its operating voltage is in the range of 2.4V to 12V. Besides that, it has a low power and high noise immunity CMOS technology. Other features that includes for this encoder are the low standby current, built-in oscillator which needs only 5% resistor, easy interface with an RF or infrared transmission media and also minimal external components. Below figure shows the pin assignment for the encoder HT 640.
Fig.4.7 PIN DIAGRAM HT 640
Table 4.3 PIN DESCRIPTION FOR ENCODER HT 640
4.5.1 Features
¢ Operating voltage: 2.4V~12V
¢ Low power and high noise immunity CMOS technology
¢ Low standby current
¢ Capable of decoding 18 bits of information
¢ Pairs with HOLTEK™s HT640 encoder
¢ 10 address pins
¢ 8 data pins
¢ Trinary address setting
¢ Two times of receiving check
¢ Built-in oscillator needs only a 5% resistor
¢ Valid transmission indictor
¢ Easily interface with an RF or an infrared transmission medium
¢ Minimal external components
4.6 DECODER HT 648
A decoder is a device which does the reverse of an encoder, undoing the encoding so that the original information can be retrieved. In digital electronics this would mean that a decoder is a multiple-input, multiple-output logic circuit that converts coded inputs into coded outputs, where the input and output codes are different. E.g. n-to-2n, BCD decoders. Enable inputs must be on for the decoder to function, otherwise its outputs assume a single "disabled" output code word. A decoder is a circuit in which a coded signal of a specific format (usually that of its compatible encoder) is received and changed to a format compatible with the circuitry interfaces with (usually the format originally presented to the encoder is the same format used for the output of the decoder when used in wireless systems, but not always). Again for this project, Holtek 318 decoder is used in which it is a series of CMOS LSIs for remote control system applications. They are paired with the 318 series of encoders. For proper operation a pair of encoder/decoder pair with the same number of address and data format should be selected. The 318 series of decoders receives serial address and data from that series of encoders that are transmitted by a carrier using and RF or and IR transmission medium. It then compares the serial input data twice continuously with its local address. If there is no error or unmatched codes are encountered, the input data codes are decoded and then transferred to the output pins. The VT pin also goes high to indicate a valid transmission.
The 318 decodes are capable of decoding 18 bits of information that consists of N bits of address and 18-N bits of data. To meet various applications, they are arranged to provide a number of data pins whose range is from 0 to 8 and an address pin whose range is from 8 to 18. In addition, the 318 decoders provide various of address/data number in different packages. Like the encoder, the decoder also has its own best features. A part from its operating voltage which is in range from 2.4V to 12V and a low power and high noise immunity of CMOS technology, this decoder has its trinary address setting. Besides that, it has two times of receiving check, built-in oscillator which only needs a 5% resistor and valid transmission indicator. It is so easy to interface with an RF or an infrared transmission medium and also it needs minimal external components. Below figure shows the pin assignment for the encoder HT 648.
Table 4.4 PIN DESCRIPTION FOR HT 648
4.6.1 Features
¢ Operating voltage: 2.4V~12V
¢ Low power and high noise immunity CMOS technology
¢ Low standby current
¢ Capable of decoding 18 bits of information
¢ Pairs with HOLTEK™s 318 series of encoders
¢ 8~18 address pins
¢ 0~8 data pins
¢ Trinary address setting
¢ Two times of receiving check
¢ Built-in oscillator needs only a 5% resistor
¢ Valid transmission indictor
¢ Easily interface with an RF or an infrared transmission medium
¢ Minimal external components
4.7 IR TRANSMITTER AND RECIEVER
Fig. 4.8 IR MODULE
4.7.1 IR LED
Fig. 4.9 IR LED
This is used as a transmitter. The IR LED or Infra Red Light Emitting Diode is an electronic device which gives off or emits light when current is passed through it. Like general diode, this IR LED passes current only in one direction and requires forward operation voltage of about 2V and forward operation current in 10 to 20 mA range. Maximum reverse voltage that the IR LED can withstand is typically 3 to 5V, more than this could damage the component. It does not have any current control function, so, when the IR LED is used in a circuit, a resistor must be used in series to limit the current flow
through it. If greater range is required, this resistor may be reduced to a minimum value with a consequent adverse effect on current consumption. Do not reduce the value of resistor unless you do require the greater range.
When the IR LED is used in an application such as the remote controlling transmitter, where the battery is the main source of current, providing continuous high current to keep the IR LED ON will consume too much of power. So when the power is applied to the IR LED, the supply is provided as pulses. If the pulse repetition frequency is rapid enough (more than 50 Hz) then to the receiver eye the IR LED will appear as continuously ON. For example, instead of supplying 25 mA current continuously, one can provided 50 mA current as pulse to get brighter light output with the same power consumption. The Infrared diode used is of plastic pack and is similar in appearance to the familiar Red LED, except that the plastic encapsulation is deep violet colour.
4.7.2 TSOP 1738
Fig. 4.10 IR SENSOR
The TSOP1738 series are miniaturized receivers for infrared remote control systems. PIN and preamplifier are assembled on lead frame, the epoxy package is designed as IR filter. The demodulated output signal can directly be decoded by a microprocessor. TSOP1738 is the standard IR remote control receiver series, supporting all major transmission codes. It is design to sense 38 KHz square wave. There are other frequencies available, but 38 KHz is the most widespread one. As TSOP sense 38 KHz modulated light, it turns output low. It is because of the output stage, which is transistor
switch. It will keep output low for some time and then again rise high- it not just sense 38 KHz but also determine if it constant 38 KHz signal, or a burst of finite number of square waves, i.e. it rejects continuous 38 KHz just like ambient light.
Block Diagram of TSOP 1738
Fig. 4.11 BLOCK DIAGRAM
Features
¢ Photo detector and preamplifier in one package
¢ Internal filter for PCM frequency
¢ Improved shielding against electrical field disturbance
¢ TTL and CMOS compatibility
¢ Output active low
¢ Low power consumption
¢ High immunity against ambient light
¢ Continuous data transmission possible (up to 2400 bps) Suitable burst length 10 cycles/burst
4.8 555 TIMER
The 555 monolithic timing circuit is a highly stable controller capable of producing accurate time delays or oscillation. In the time delay mode of operation, the time is precisely controlled by one external resistor and capacitor. For a stable operation as an oscillator, the free running frequency and the duty cycle are both accurately controlled with two external resistors and one capacitor. The circuit may be triggered and reset on falling waveforms, and the output structure can source or sink up to 200mA.
4.8.1 Features
¢ High Current Drive Capability (200mA)
¢ Adjustable Duty Cycle
¢ Temperature Stability of 0.005%/°C
¢ Timing from µSec to Hours
¢ Turn off Time Less than 2µSec
Fig. 4.12 TIMER INTERNAL BLOCK DIAGRAM
4.8.2 Monostable Operation
Fig.4.14 WAVEFORMS OF MONOSTABLE OPERATION
Figure illustrates a monostable circuit. In this mode, the timer generates a fixed pulse whenever the trigger voltage falls below Vcc/3. When the trigger pulse voltage applied to the #2 pin falls below Vcc/3 while the timer output is low, the timer's internal flip-flop turns the discharging Tr. off and causes the timer output to become high by charging the external capacitor C1and setting the flip-flop output at the same time. The voltage across the external capacitor C1, VC1 increases exponentially with the time constant t=RA*C and reaches 2Vcc/3 at td=1.1RA*C. Hence, capacitor C1 is charged through resistor RA.
The greater the time constant RAC, the longer it takes for the VC1 to reach 2Vcc/3. In
Other words, the time constant RAC controls the output pulse width. When the applied voltage to the capacitor C1 reaches 2Vcc/3, the comparator on the trigger terminal resets the flip-flop, turning the discharging Tr. on. At this time, C1 begins to discharge and the timer output converts to low. In this way, the timer operating in monostable repeats the above process. Figure 2 shows the general waveforms during monostable operation.
It must be noted that, for normal operation, the trigger pulse voltage needs to maintain a minimum of Vcc/3 before the timer output turns low. That is, although the output remains unaffected even if a different trigger pulse is applied while the output is high, it may be affected and the waveform not operate properly if the trigger pulse voltage at the end of the output pulse remains at below Vcc/3.
4.8.3 Astable Operation
Fig.4.15 ASTABLE CIRCUIT
Fig.4.16 WAVEFORMS OF ASTABLE OPERATION
An astable timer operation is achieved by adding resistor RB to Figure 1 and configuring as shown on Figure 1. In astable operation, the trigger terminal and the threshold terminal are connected so that a self-trigger is formed, operating as a multi vibrator. When the timer output is high, its internal discharging Tr. turns off and the VC1 increases by exponential function with the time constant (RA+RB)*C. When the VC1, or the threshold voltage, reaches 2Vcc/3, the comparator output on the trigger terminal becomes High, resetting the F/F and causing the timer output to become low. This in turn turns on the discharging Tr. and the C1 discharges through the discharging channel formed by RB and the discharging Tr. When the VC1 falls below Vcc/3, the comparator output on the trigger terminal becomes high and the timer output becomes high again. The discharging Tr. turns off and the VC1 rises again. In the above process, the section where the timer output is high is the time it takes for the VC1 to rise from Vcc/3 to 2Vcc/3, and the section where the timer output is low is the time it takes for the VC1 to drop from 2Vcc/3 to Vcc/3.
4.9 GEAR DC MOTOR
Whenever a robotics hobbyist talk about making a robot, the first thing comes to his mind is making the robot move on the ground. And there are always two options in front of the designer whether to use a DC motor or a stepper motor. When it comes to speed, weight, size, cost. DC motors are always preferred over stepper motors. There are many things which you can do with your DC motor when interfaced with a microcontroller. For example you can control the speed of motor, you can control the direction of rotation, you can also do encoding of the rotation made by DC motor i.e. keeping track of how many turns are made by your motors etc. So you can see DC motors are no less than a stepper motor.
Fig.4.17 INTERNAL STRUCTURE OF DC MOTOR
In this part we are using geared DC motor with combination of gear to get a specific RPM. The shaft is connected to gear box which in turn connected to shaft of the DC motor. Below figure shows simple gear combination.
Fig. 4.18 GEAR COMBINATION
4.10 CAMERA AND RF RECEIVER
4.10.1 Camera
A camera is a device that records images, either as a still photograph or as moving images known as videos or movies.
A majority of cameras have a lens positioned in front of the camera's opening to gather the incoming light and focus all or part of the image on the recording surface. The diameter of the aperture is often controlled by a diaphragm mechanism, but some cameras have a fixed-size aperture.
Colour camera is a CMOS Charging OR Coupling Device (CCD). Here we use convex (bulge) lens. In convex lens. We see inverse images. For video transmission we use 5.5 MHz .In video signals AM modulation takes places. Then it multiplexed and transmits signal. At receiver reception takes place. Where demodulation occurs we get pure video of 1 volts peak to peak and display in monitor. Linear Transmission Distance: 50-100m.
Technical parameters of transmitting unit:
¢ Size: only 38x28x16mm
¢ Video Camera Parts: 1/3CMOS, 1/4 Image Sensors
¢ System: PAL/CCIR NTSC/EIA
¢ Effective Pixel: PAL: 628 x 582, NTSC: 510 x 492
¢ Image Area: PAL: 5.78 x 4.19mm, NTSC: 4.69 x 3.45mm
¢ Horizontal Definition: 380 Lines
¢ Scanning Frequency: PAL/CCIR: 50Hz, NTSC/EIA: 60Hz
¢ Minimum Illumination: 3 LUX
¢ Sensitivity: +18DB-AGL On-Off
¢ Electrical Level Output: 50mW
¢ Frequency Output: 1.2 GHz
¢ Transmission Signal: Audio, Video
¢ Linear Transmission Distance: 50-100m
¢ Voltage: DC+9V
¢ Current: 300mA
¢ Power Dissipation: 640mW
Fig. 4.19 CAMERA AND RECEIVER
4.10.2 Camera RF Receiver:
In this section the signals are received and accordingly the action takes place.
We have connected a wireless camera to this unit which will send the audio and video signals to the computer monitor through a PCI based TV tuner card.
Technical parameters of receiving unit:
¢ Wireless Audio/Video Receiver
¢ Receiving Method: Electronic Frequency Modulation
¢ Reception Sensitivity: +18dB
¢ Receiving Frequency: 1.2 GHz
¢ Receiving Signal: Audio, Video
¢ Voltage: DC+12V
¢ Current: 500Ma
4.11 BATTERY
Batteries are an excellent emergency power source, but require some basic information to use properly. They are electrochemical devices. They have plates, usually metallic, and either a solution or a moist compound between the plates. A chemical reaction takes place in the battery when it is discharged that produces a flow of electrons out one plate on the negative side and into another plate on the positive side.
Here we are using dry lead/acid battery. It has plates of lead in sulphuric acid solution in water. One of the sets of lead plates is coated with lead dioxide. As such a battery discharges it creates two chemical reactions, one at the anode that ends up with an excess of electrons, and one at the cathode that ends up short electrons. If a wire is connected between the two, the excess electrons from the anode will travel through the wire as a current to the cathode where they are needed to complete the electron deficient reaction there.
Dry lead acid battery of 12V/1.3A is used as source of power for the whole robot unit. For digital circuitry 5 volts needed is derived from 12v battery using regulator IC7805.
4.12 REGULATOR:
A discrete voltage regulator fabricated on a single chip, it is called monolithic voltage regulator. These regulators have:
i. High performance (ideal 100% regulation)
ii. Low cost.
iii. Reduced size.
iv. Easier to use.
Usually monolithic voltage regulator is available as 3 terminals IC7805 as shown in below figure. The 3 terminals are denoted as IN (input), COM (common), OUT (output). This +5V regulator is useful in power up to 500mw.It must have a heat sink for high current. A 1mf high quality and tantalum capacitor should be placed from output to ground for stability. By using this regulator circuit we are deriving 5v from 12v battery.
Fig. 4.21 REGULATOR CIRCUIT
CHAPTER 5
SYSTEM IMPLEMENTATION
5.1 PCB LAYOUT
5.1.1 Main Board
Fig. 5.1 MAIN BOARD PCB
5.1.2 555 Astable (IR Emitter)
Fig. 5.2 IR EMITTER PCB
5.1.3 555 Monostable (IR Trigger)
Fig. 5.3 IR TRIGGER PCB
5.2 PCB DESIGN
PCB design starts right from the selection of the laminates .The two main types of base laminate are epoxy glass and phenolic paper laminates are generally used for simple circuits. Though it is very cheap and can easily be drilled, phenolic paper has poor electrical characteristics and it absorbs more moisture than epoxy glass. Epoxy glass has higher mechanical strength.
The important properties that have to be considered for selecting the PCB substrate are the dielectric strength, insulation resistance, water absorption property, coefficient of thermal expansion, shear strength, hardness, dimensional stability etc.
5.2.1 PCB Fabrication
The fabrication of a PCB includes four steps.
a) Preparing the PCB pattern.
b) Transferring the pattern onto the PCB.
c) Developing the PCB.
d) Finishing (i.e.) drilling, cutting, smoothing, turning etc.

Pattern designing is the primary step in fabricating a PCB. In this step, all interconnection between the components in the given circuit are converted into PCB tracks. Several factors such as positioning the diameter of holes, the area that each component would occupy, the type of end terminal should be considered.
5.2.2 Transferring the PCB Pattern
The copper side of the PCB should be thoroughly cleaned with the help of alcoholic spirit or petrol. It must be completely free from dust and other contaminants.
The mirror image of the pattern must be carbon copied and to the laminate the complete pattern may now be made each resistant with the help of paint and thin brush.
5.2.3 Developing
In this developing all excessive copper is removed from the board and only the printed pattern is left behind. About 100ml of tap water should be heated to 75 ° C and 30.5 grams of FeCl3 added to it, the mixture should be thoroughly stirred and a few drops of HCl may be added to speed up the process.
The board with its copper side facing upward should be placed in a flat bottomed plastic tray and the aqueous solution of FeCl2 poured in the etching process would take 40 to 60 min to complete.
After etching the board it should be washed under running water and then held against light .the printed pattern should be clearly visible. The paint should be removed with the help of thinner.
5.2.4 Finishing Touches
After the etching is completed, hole of suitable diameter should be drilled, then the PCB may be tin plated using an ordinary 35 Watts soldering rod along with the solder core, the copper side may be given a coat of varnish to prevent oxidation.
5.2.5 Drilling
Drills for PCB use usually come with either a set of collects of various sizes or a 3-Jaw chuck. For accuracy however 3-jaw chunks arenâ„¢t brilliant and small drill below 1 mm from grooves in the jaws preventing good grips.
5.2.6 Soldering
Begin the construction by soldering the resistors followed by the capacitors and the LEDs diodes and IC sockets. Donâ„¢t try soldering an IC directly unless you trust your skill in soldering. All components should be soldered as shown in the figure. Now connect the switch and then solder/screw if on the PCB using multiple washers or spaces. Soldering it directly will only reduce its height above other components and hamper in its easy fixation in the cabinet. Now connect the battery lead.
5.2.7 Assembling
The circuit can be enclosed in any kind of cabinet. Before fitting the PCB suitable holes must be drilled in the cabinet for the switch, LED and buzzer. Note that a rotary switch can be used instead of a slide type.
Switch on the circuit to be desired range. It will automatically start its timing cycles. To be sure that it is working properly watch the LED flash. The components are selected to trigger the alarm a few minutes before the set limit.
CHAPTER 6
SOFTWARE DESCRIPTION
6.1 FLOW CHART
Fig. 6.1 FLOW CHART
6.2 PROGRAM
ORG 0000H
;------------------------------------------------------------------------------------
MOV P1,#0FFH
MOV P0,#0FFH
MOV P2,#00H
;------------------------------------------------------------------------------------
SETB P2.0
SETB P2.1
SETB P2.2
SETB P2.3
MAIN:
MOV A,P1 ;STOP
ANL A,#11111111B
CJNE A,#00000001B,L1;STP
CLR P2.0
CLR P2.1
CLR P2.2
CLR P2.3
ACALL DELAY
LJMP MAIN

L1: CJNE A,#00000010B,L2 ;FWD
CLR P2.1
CLR P2.2
SETB P2.0
SETB P2.3
ACALL DELAY
LJMP MAIN
L2: CJNE A,# 00000100B,L3 ;REV
CLR P2.0
CLR P2.3
SETB P2.1
SETB P2.2
ACALL DELAY
LJMP MAIN
L3: CJNE A,#00001000B,L4 ;LEFT
CLR P2.0
CLR P2.2
SETB P2.1
SETB P2.3
ACALL DELAY
LJMP MAIN
L4: CJNE A,#00010000B,L5 ;RIGHT
CLR P2.1
CLR P2.3
SETB P2.0
SETB P2.2
ACALL DELAY
LJMP MAIN
L5: CJNE A,#00000011B,MAIN ;IR
MAIN1:
MOV A,P0
ANL A,#00000111B
CJNE A,#00000010B ,L6 ;FORNT IR
CLR P2.0
CLR P2.3
SETB P2.1
SETB P2.2
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
CLR P2.1
CLR P2.3
SETB P2.0
SETB P2.2
ACALL DELAY
SETB P2.0
SETB P2.1
SETB P2.2
SETB P2.3
LJMP MAIN1
L6: CJNE A,#00000001B,L7 ;RIGHT IR
CLR P2.0
CLR P2.2
SETB P2.1
SETB P2.3
ACALL DELAY
SETB P2.0
SETB P2.1
SETB P2.2
SETB P2.3
LJMP MAIN1
L7: CJNE A,#00000100B,L8 ;LEFT IR
CLR P2.1
CLR P2.3
SETB P2.0
SETB P2.2
ACALL DELAY
SETB P2.0
SETB P2.1
SETB P2.2
SETB P2.3
LJMP MAIN1
L8: CJNE A,#00000000B,L9
CLR P2.1
CLR P2.2
SETB P2.0
SETB P2.3
ACALL DELAY
SETB P2.0
SETB P2.1
SETB P2.2
SETB P2.3
LJMP MAIN1
L9: MOV A,P1
ANL A,#00011111B
CJNE A,#00000001B,MAIN1
CLR P2.0
CLR P2.1
CLR P2.2
CLR P2.3
ACALL DELAY
SETB P2.0
SETB P2.1
SETB P2.2
SETB P2.3
LJMP MAIN
DELAY: MOV R1,#10H
N1: MOV R2,#0FFH
N2: DJNZ R2,N2
DJNZ R1,N1
RET
END
CHAPTER 7
APPLICATIONS AND ADVANTAGES
7.1 APPLICATIONS
i. Military surveillance
ii. Space Exploration.
iii. Hazardous Area Maintenance like Nuclear Power Reactors.
iv. Mining.
v. Hospitals - To Maintain Sterile Environment.
vi. Industrial Automated Equipment Carriers.
vii. Tour Guides in Museums and Other Similar Applications.
7.2 ADVANTAGES
i. Circuit is very simple.
ii. Components used are economical.
iii. Compact, Power Efficient.
iv. No Manual Interpretation Required.
v. Accuracy Is Very High.
vi. Can Be Used In All Kinds Of Environment.
vii. Robots never get sick or need to rest, so they can work 24 hours a day, 7 days a week.
viii. When the task required would be dangerous for a person, they can do the work instead.
ix. Robots don't get bored, so work that is repetitive and unrewarding is no problem for a robot.
CHAPTER 8
FUTURE ENHANCEMENTS
i. Distance sensing and position logging & transmission
ii. Use of solar power
iii. Multiple sensors like thermal etc
iv. Radar Implementation.
v. Equipped with Missiles
vi. Night vision
CONCLUSION
A defence surveillance robot was designed in the project. Using the RF remote control and sensors to sense the path and obstacles, controller program was designed so as to enable the microcontroller to control robot, using RF remote and movement of the robot and move when there is no obstacle in the following path. The program could also read data from sensors and produce the controlling actions respectively. The motor drivers are used to drive the motor. Obstacle sensors are used to change the movement of robot when the robot faces an obstacle on the path.
The project has been accomplished with the help of KEIL C compiler and ATMEL programmer. The project has been tested successfully and has been approved by the concerned project guides.
BIBLIOGRAPHY
REFERENCE BOOKS
[1] Muhammad Ali Mazidi “THE 8051 MICROCONTROLLER AND EMBEDDED SYSTEMS, Pearson education,
[2] Ayala- INTRODUCTION TO 8051 MICROCONTROLLER
SOFTWARES
[1] Keil C51 compiler user guide (Keil Software V3.60)
WEB LINKS

[1] 8052.com
[2] google.com
[3] robotroom.com
[4] roboticsindia.com
[5] wekipedia.org
[6] keil.com
[7] datasheetarchive.com
[8] atmel.com
[9] 8051projects.info
[10] 8051projects.net
[11] rentron.com
APPENDIX