Final Mini Project Documentation

8/2/2019 Final Mini Project Documentation

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Chapter 1

INTRODUCTION

The line following robot is programmed to follow a white line on a black background and

detect turns or deviations and modify the motors appropriately. The optical sensor is an array of

commercially available IR reflective type sensors.

The core of the robot is the AT89C2051 microcontroller. The speed control of the motors

is achieved by the two PWM modules in the microcontrollers. The direction control is provided

by 2 I/O pins. The H-Bridge motor driving/control chip takes these signals and translates it into

current direction entering the motor armature. The motors require separate supply for operation.

The differential steering system is used to turn the robot. In this system, each back wheel

has a dedicated motor while the front wheels are free to rotate. To move in a straight line, both

the motors are given the same voltage (same polarity). To manage a turn of different sharpness,

the motor on the side of the turn required is given lesser voltage. To take a sharp turn, its polarity

is reversed.

The sensor is an array IR LED-Phototransistor pairs arranged in the form of an inverted

V. The output of each sensor is fed into an analog comparator with the threshold voltage (used to

calibrate the intensity level difference of the line with respect to the surface). These 7 signals

(from each photo-reflective sensor) is given to a priority encoder, the output of which to the

microcontroller.

The control has 6 modes of operation, turn left/right, move left/right, and drift left/right.

The actual action is caused by controlling the direction/speed of the two motors (the two back

wheels), thus causing a turn. The actual implementation is a behavior based (neural) control with

the sensors providing the inputs. The robot can also be programmed to find the line by pseudo-

random movement in case no line is detected by the optical sensor.


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What is a line follower?

Line follower is a machine that can follow a path. The path can be visible like a black

line on a white surface (or vice-versa) or it can be invisible like a magnetic field.

Why build a line follower?

Sensing a line and maneuvering the robot to stay on course, while constantly correction

wrong moves using feedback mechanism forms a simple yet effective closed loop system.

We have seen how ants always travel in a line, following an invisible route in search

of food, or back home. How on roads we follow lanes to avoid accidents and traffic jams.

Programming intelligence into a robot (or computer) is a difficult task and one that

has not been very successful to date even when supercomputers are used. This is not to say

that robots cannot be programmed to perform very useful, detailed, and difficult tasks; t h e y

ar e. Some t as ks a re impossible for hu ma ns t o pe r fo rm qu i ck l y an d productively.

For instance, imagine trying to solder 28 filament wires to a 1/4in square sliver of silicon in

2 s to make an integrated circuit chip. Its not very likely that a human would be able to

accomplish this task without a machine. But machine task performance, as impressive as it is,isnt intelligence.

1.1 PROBLEM DEFINITION

In the industry carriers are required to carry products from one manufacturing plant

to another which are usually in different buildings or separate blocks.

Conventionally, cars or trucks w e r e u se d w i t h human drivers. Unreliability and

inefficiency in this part of the assembly line formed the weakest link. The project is toautomate this sector, using carts to follow a line instead of laying railway tracks which are both

costly and an inconvenience.


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1.2 OBJECTIVES OF THE STUDY

The robot must be capable of following a line. It must be prepared of a situation that it runs into a territory which has no line to

follow. (Barren land syndrome) The robot must also be capable of following a line even if it has breaks.

The robot must be insensitive to environmental factors such as lighting and noise.

It m ust allow calibration of the lines darkness threshold.

The robot must be reliable

Scalability must be a primary concern in the design.

The color of the line must not be a factor as long as it is darker than the

surroundings.


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Chapter 2

BLOCK DIAGRAM & CIRCUIT DIAGRAM

2.1 BLOCK DIAGRAM

The infrared sensors are used to sense the line. When the infrared signal falls on the white

surface, it gets reflected and if it falls on the black surface, it is not reflected this principle is used

to scan the Lines for the Robot. The microcontroller AT89C51 is used to control the motors. It

gets the signals from the infrared sensors and it drives the motors according to the sensor inputs.

Two stepper motors are used to drive the robot. The block diagram as shown in figure 2.1

Figure -2.1 Block diagram of Line Following Robot

The Comparator present after the sensor array will help in the noticing the line that is

sensed, i.e. it will compare the sensed line with the needed one. This will indeed result in the

proper functioning of the microprocessor to give instructions to the motor. The working of the

robot involves the movement of the wheels. If the IR sensor senses the line, both the wheels are

in motion. However, when there is a case when a line in not sensed, i.e. during the turnings then

the microcontroller controls the wheels in such a fashion that when there is a right turn, the left

wheel will rotate while the right one is motion-less so that the total body will turn to the right and

vice-versa.


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2.2 CIRCUIT DIAGRAM

The schematic of the Line Following R obot is shown in the figure 2.2. The main

component is the AT89C51 microcontroller. The schematic is divided into two sections; one

the Sensor Array Board, and the other the motor-control or main board.

The main features incorporated into the circuit are given below

The at89c51 microcontroller

The voltage regulator

Crystal oscillator (4MHz)

The H-bridge motor control IC (L293D)

Motors, with coupled reduction gears.

The LM324 quad comparator IC

A POT to calibrate the reference voltage.


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Figure 2.2 Circuit Diagram of Line Tracking Robot

The motors are connected to port-1 of micro-controller using motor driver L293D and the sensor

array is connected to port-3.


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Figure 2.3 Sensor Circuit with Comparator IC LM324


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CHAPTER 3

HARDWARE DESCRIPTION

3.1. ATMEL 89C51 MICRO CONTROLLER

3.1.1. Introduction

The AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcontroller with

2K bytes of Flash programmable and erasable read-only memory (PEROM). The device is

manufactured using Atmels high -density nonvolatile memory technology and is compatible with

the industry-standard MCS-51 instruction set. By combining a versatile 8-bit CPU with Flash on

a monolithic chip, the Atmel AT89C2051 is a powerful microcomputer which provides a highly-

flexible and cost-effective solution to many embedded control applications.

The AT89C2051 provides the following standard features: 2K bytes of Flash, 128 bytes

of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a

full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In

addition, the AT89C2051 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 hardware reset.

3.1.2. Features

Compatible with MCS-51Products

2K Bytes of Reprogrammable Flash Memory Endurance: 10,000 Write/Erase Cycles

2.7V to 6V Operating Range

Fully Static Operation: 0 Hz to 24 MHz


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Two-level Program Memory Lock

128 x 8-bit Internal RAM 15 Programmable I/O Lines

Two 16-bit Timer/Counters

Six Interrupt Sources

Programmable Serial UART Channel

Direct LED Drive Outputs On-chip Analog Comparator

Low-power Idle and Power-down Modes

Green (Pb/Halide-free) Packaging Option

3.1.3 Pin Diagram & Description

Figure - 3.1 Pin Diagram


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VCC:

Supply voltage.

GND:

Ground.

Port 0:

Port 0 is an 8-bit open drain bi-directional 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 bi-directional 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. 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 table 3.1.1. Port 1 also receives the low-order address bytes

during Flash programming and verification.

Port 2:



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 memory

that uses 16-bit addresses (MOVX @DPTR).

In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses

to external data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of


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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:



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 also serves the functions of various

special features of the AT89C51, as shown in table 3.1.2. Port 3 also receives some control

signals for Flash programming and verification.

Port Pin Alternate Functions

P3.0 RXD (Serial input port)

P3.1 TXD (Serial output port)

P3.2 INT0 (external interrupt 0)

P3.3 INT1 (external interrupt 1)

P3.4 T0 (timer 0external interrupt)

P3.5 T1 (timer 1 external input)

P3.6 WR (external data memory write strobe)P3.7 RD (external data memory read strobe)

Table - 3.1 Alternate Functions of Port 3

RST:

Reset input. A high on this pin for two machine cycles while the oscillator is runningresets the device.

ALE/PROG :

Address Latch Enable, 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 that one ALE pulse is


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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 is the read strobe to external program memory. When the

AT89C51 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 12volt 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.


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3.1.4. Architecture of AT89C51

Program Counter and Data Pointer:-

Figure - 3.2 Internal Architecture of AT89C51

The 89C51 contains two 16-bit registers: the Program Counter (PC) and the data pointer

(DPTR). Each is used to hold the address of a byte in memory. The PC is the only register thatdoes not have an internal address. The DPTR is under the control of program instructions and

can be specified by its 16-bit name, DPTR, or by each individual byte name, DPH and DPL.

DPTR does not have a single internal address; DPH and DPL are each assigned an address.


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A & B Registers:

The 89C51 contains 34 general purpose working registers. Two of these registers A and

B, hold results of many instructions, particularly math and logical operations of the 89C51 CPU.

The other 32 are arranged as part of internal RAM in four banks, B0-B3 of eight registers. The A

register is also used for all data transfers between the 89C51 and any external memory. The B

register is used with the A register for multiplication and division operations.

The Stack and Stack Pointer:

The stack refers to an area of internal RAM that is used in conjunction with certain

opcodes to store and retrieve data quickly. The 8-bit stack pointer register is used by the 89C51

to hold an internal RAM address that is called the top of the stack. The address held in the SP

register is the location in internal RAM where the last byte of data was stored by a stack operation. When data is to be placed on the stack, the SP is incremented before storing data on

the stack. As data is retrieved from the stack, the SP decrements to point to the next available

byte of stored data.

Program Status Word (PSW):

Flags may be conveniently addressed, they are grouped inside the program status word

(PSW) and the power control (PCON) registers. The 89C51 has four math flags that respond

automatically to the outcomes of math operations and three general-purpose user flags that can

be set to 1 or cleared to 0 by the programmer as desired. The math flags include Carry (C),

Auxiliary Carry (AC), Overflow (OV), and Parity (P).

Timers:

Timer 0 and 1:

Timer 0 and Timer 1 in the AT89C51 operate the same way as Timer 0 and Timer 1 in

the AT89C51.

3.2 D.C MOTORS

DC motors are widely used, inexpensive, small and powerful for their size.

Reduction gearboxes are often required to reduce the speed and increase the torque output of


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the motor.

Several characteristics are important when selecting DC motors and these can be split

into two specific categories. The first category is associated with the input ratings of the motor

and specifies its electrical requirements, like operating voltage and current. The second

category is related to the motors output characteristics and specifies the physical limitations

of the motor in terms of speed, torque and power.

Example specifications of the motors used are given below in table 3.2

Characteristic Value

Operating Voltage: 6V to 12V

Operating Current: 2A Max. (Stall)

Speed: 2400 rpm

Torque: 30 gm-cm

Table - 3.2 Specifications of Motor

As noticed, the torque provided can hardly move 30gm of weight around with wheel

diameter of about 2cm. This is a fairly a huge drawback as the robot could easily weigh

about a kg. This is accomplished by gears which reduce the speed (2400 rpm is highly

impractical) and effectively increase the torque. If the speed is reduced by using a gear

system by a factor of t hen the torque is increased by the same factor. For

example, if the speed is reduced from 2400 rpm, to 30 rpm, then the torque is increased by a

factor of (2400/30 = 80) in other words the torque becomes 30 80 2400 gm-cm or

2.4 kg-cm which is more than sufficient.

3.3 H-BRIDGE MOTOR CONTROL

DC motors are generally bi-directional motors. That is, their direction of rotation can

be changed by just reversing the polarity. But once the motors are fixed, control becomes


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tricky. This is done using the H-Bridge. The table 3.4 shows the H-Bridge operation

Table - 3.3 H-Bridge action

Figure 3.3 H-Bridge Using Relays.

If A & D are turned on, then the current flows in the direction shown in the figure 3.4

A B C D ACTION

1 0 0 1 CLOCKWISE

0 1 1 0 COUNTER-CLOCKWISE

0/1 0/1 1/0 1/0 BRAKE

ANY OTHER STATE FORBIDDEN


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Figure - 3.4 Clockwise Rotation

If B & C are turned on, then the motor rotates in counter clockwise direction as shown in

figure 3.5

Figure - 3.5 Counter-Clockwise Rotation


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3.4. POWER SUPPLY

A power supply can be broken down into a series of blocks, each of which performs a

particular function as shown below.

For example a 5V regulated supply

Figure 3.6 Block Diagram of Regulated Power Supply

The Transformer steps down high voltage AC mains to low voltage AC. The Rectifier is

used to convert AC to DC, but the DC output is varying. The Smoothing filter smoothes the DC

from varying greatly to a small ripple. The Regulator eliminates ripple by setting DC output to a

fixed voltage. The blocks of power supply unit are as shown in figure 3.7

Figure - 3.7 Block diagram of power supply unit

The regulated DC output is very smooth with no ripple. It is suitable for all electronic

circuits.
http://www.kpsec.freeuk.com/powersup.htm#transformerhttp://www.kpsec.freeuk.com/powersup.htm#transformer


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3.5. VOLTAGE REGULATOR

It has been shown that practically all electronic devices need DC supply. A direct

voltage of constant magnitude requires to be supplied, for the smooth and efficient

functioning of these devices. A properly designed voltage regulator ensures that,

irrespective of change in supply voltage, load impedance or temperature, the DC supply is

maintained at a constant level. This is achieved by incorporating some type of feedback in the

regulator circuit.

An IC voltage regulator unit contains all the circuitry required in a single IC. Thus there

are no discrete components and the circuitry needed for the reference source, the comparator

and control elements are fabricated on a single chip. Even the over load and short-circuit

protection mechanism is integrated into the IC. IC voltage regulators are designed to provide

either a fixed positive or negative voltage, or an adjustable voltage which can be set for any

value ranging between two voltage levels.

Figure - 3.8 Voltage Regulator

The circuit requires two voltage sources, one for the digital ICs (+5V) and a+12V to

the motors. The motor is supplied 12V unregulated supply directly from the battery as

regulation would be difficult and unnecessary; whereas the digital ICs and the microcontroller


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require a perfect ripple free +5V to function properly. The L7805C is a5V voltage regulator

IC. The capacitors added to the input of the voltage regulator are to isolate the spikes generated

by the motor from the input and to reduce noise. The 10 F capacitor at the output is to

maintain stability and improve regulation. These are standard values. The 0.1 F capacitor is

used at the input because of the fact that high value capacitors have poor high frequency

response.

IC Voltage Regulator:

Voltage regulator ICs are available with fixed (typically 5, 12 and 15V) or variable

output voltages. They are also rated by the maximum current they can pass. Negative voltage

regulators are available, mainly for use in dual supplies. Most regulators include some automatic

protection from excessive current ('overload protection') and overheating ('thermal protection').

Many of sthe fixed voltage regulator ICs have 3 leads and 7805 +5V 1A regulator shown in the

figure 3.9

Figure - 3.9 Regulator

3.6 D.C Motors

The D.C. motors have a speed of 2400rpm and a torque of 15gm-cm. The gears

decrease the speed to 30rpm at 6V and thus considerably increasing the torque so that the robotcan carry the load of its frame and the lead-acid battery. Two such motors are used in the rear

of the robot, and a dummy castor is fixed to the front to stabilize the robot.


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3.7. THE H-BRIDGE CONTROL HARDWARE

Figure 3.10 Motor Control .


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The entire motor control circuitry is shown in the above figure 3.7.1 along with the

internal circuitry of the L293D motor control IC. The table below clearly indicated the operation

of the IC.

Table 3.4 Motor Movement

Figure 3.11 Motor Driver L293D Pin Diagram

IN1 IN2 IN3 IN4 OPERATION

1 0 1 0 BOTH MOTORS FORWARD

(MOVE FORWARD)

0 1 0 1 BOTH MOTORS BACKWARD

(MOVE BACKWARD)1 0 0 1 RIGHT MOTOR BACKWARD

LEFT MOTOR FORWARD

(TURN RIGHT)

0 1 1 0 RIGHT MOTOR FORWARD

LEFT MOTOR BACKWARD

(TURN LEFT)


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3.10 THE IR SENSORS

The MOC7811 consists of an infrared emitting diode ( = 950nm) and an NPN

silicon phototransistor mounted to face each other on a converging optical axis in a black

plastic housing. The photo-transistor responds to radiation from the emitting diode only when

no object is present within its field of view. This sensor is physically modified so that the

emitter and detector face the same direction and thus the modified sensor serves the purpose

of an optical-reflective sensor. The sensor has a focal length of 8mm, thus the surface must be

at an optimum distance of 1.6cm.

Figure - 3.12 Sensors Working

If a reflective (white) surface is present at the optimal distance (d = 1.6cm) then the

reflected waves will strike the detector which on radiation will start to conduct. The circuit

diagram is shown in the figure 3.13

Figure - 3.13 The Sensor


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The drop across the emitter when forward biased is around 1.4V. According to the data

sheets, to have sustained radiation, a max of 40mA must flow through to avoid damage. A

safe margin is allowed and a current of 16mA is considered for the design.

R = Vcc Vd

Ic

for, Vcc = 5V Vd

= 1.4V

Ic = 16mA

R is calculated to be approximately 220 .

For the emitter, the collector resistor was determined experimentally on a trial and error

basis. It was decided to use a value of 56 k . For this value, the potential across the detector is

normally 4.6V, when an object reflects the rays towards the detector, then the potential drops

to 0.6V. The output is obviously analog in nature.

3.10. COMPARATOR

A comparator is a circuit which compares a signal voltage applied at one input of an

op-amp with a known reference voltage at the other input, and produces either a high or a

low output voltage, depending on which input is higher. The input / output

characteristics of a comparator is as shown.

Figure - 3.14 Comparator transfer characteristics.


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Figure 3.15 Comparator LM324 Pin Diagram

The reference voltage is generated by the 20k POT and given to all the

comparators to the non-inverting input. When the respective sensor is on the line, theemitted light is absorbed by the line and the transistor is the cut-off mode, thus a potential of

4.6V is given to the inverting input which is greater than V ref (which is chosen to be 2.5V),

thus the output of the comparator goes low. When the sensor is not on the line the potential

across the detector is usually 0.6V. Thus the output of the comparator goes high. Thus the

output of the comparator goes low only when the sensor is over the line. The comparator is

open collector, and hence a pull-up resistor of 10 k is required at the output.

3.11. SENSOR ARRAY

The resistance of the sensor decreases when IR light falls on it. A good sensor will have near zero

resistance in presence of light and a very large resistance in absence of light. The schematic of a single

sensor is shown in figure 3.16


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Figure - 3.16 Schematic of a Single Sensor

We have used this property of the sensor to form a potential divider. The potential at point 2 isRsensor / (Rsensor + R1). Again, a good sensor circuit should give maximum

change in potential at point 2 for no-light and bright-light conditions. This is especially

important if you plan to use an ADC in place of the comparator .

To get a good voltage swing, the value of R1 must be carefully chosen. If Rsensor = a

when no light falls on it and Rsensor = b when light falls on it . The transfer characteristics of

a resistance and voltage swing in shown in figure 3.17

Figure 3.17 transfer characteristics of Resistance and Voltage swing


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The difference in the two potentials is

Vcc * {a/ (a+R1) - b/ (b+R1)}

Relative voltage swing = Actual Voltage Swing / Vcc

= Vcc * {a/ (a+R1) - b/ (b+R1)} / Vcc

= a/(a+R1) - b/(b+R1)

The sensor used has a= 930 K and b= 36 K.If we plot a curve of the voltage swing over a

range of values of R1 we can see that the maximum swing is obtained at R1= 150 K. There is a

catch though, with such high resistance, the current is very small and hence susceptible to bedistorted by noise. The solution is to strike a balance between sensitivity and noise immunity.


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CHAPTER5

SOURCE CODE

THE SOFTWARES USED

5.1 KEIL VISION 4: KEIL implemented the first C compiler designed from the ground up specifically for

8051 microcontroller. Keil provides broad range of development tools like ANSI C Compiler,

macro assembler, debuggers and simulators, linkers, IDE library managers, real time operating

system & evaluation boards for 8051 & ARM families. It is used to write programs for an

application. The programs can be written in embedded C or in assembly language. The program

thus written is dumped into the microcontroller using flash magic software.

5.2 FLASH MAGIC SOFTWARE :

The FLASH MAGIC software is one of the best known microcontroller programs

dumping software. It has the compatibility with the KEIL software. The HEX file generated by

the KEIL is used by the FLASH MAGIC to program the microcontroller. The software uses the

computer serial port to transmit data into microcontroller.

To dump the code program first the FLASH MAGIC has to be provided with necessary

information about the target, the baud rate supported, the clock frequency, etc, then the software

checks for the device connected to the computer serial port. If the target is not connected, an

error is generated.

The software then checks for the available memory and the size of file to be dumped.

Then it checks whether the target (microcontroller) is in ISP (In system programming) mode or

not. If everything is fine then, it starts writing into the microcontroller using the serial data

transfer pins Txd and Rxd pins on the microcontroller.


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THE SOURCE CODE AS FOLLOWS:

sbit ir1=p1^0;

sbit ir2=p1^1;

sfr dcmotors=0x80;

void sensors (void);

void delay (unsigned char value)

{

int i, j;

for (I=0, i


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{

if (ir1==0)

{

dcmotors=0x04;

delay (2);

}

if (ir2==0)

{

dcmotors=0x01;

}

if (ir1==0&&ir2==0)

{

dcmotors=0x0A;

delay (100);

dcmotors=0x00;

}

}


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APPLICATIONS & CONCLUSION

APPLICATIONS AND LIMITATIONS

APPLICATIONS Industrial automated equipment carriers

Entertainment and small household applications.

Automated cars.

Tour guides in museums and other similar applications.

Second wave robotic reconnaissance operations.

LIMITATIONS Choice of line is made in the hardware abstraction and cannot be changed by

software.

Calibration is difficult, and it is not easy to set a perfect value.

The steering mechanism is not easily implemented in huge vehicles and

impossible for non-electric vehicles (petrol powered).

Few curves are not made efficiently, and must be avoided.

Lack of a four wheel drive, makes it not suitable for a rough terrain.

1.3.SCOPE OF STUDY

The robot can be further enhanced to let the user decide whether it is a dark line on a

white background or a white line on a dark background. The robot can also be programmed

to decide what kind of line it is, instead of a user interface. The motor control could be


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modified to steer a convectional vehicle, and not require a differential steering system. The

robot could be modified to be a four wheel drive. Extra sensors could be attached to allow

the robot to detect obstacles, and if possible bypass it and get back to the line. In other

words, it must be capable predicting the line beyond the obstacle. Speed control could also be

incorporated


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BIBLIOGRAPHY

PICmicro Mid-Range MCU Family Reference Manualby

MICROCHIP

Digital logic and computer design

by M. Morris Mano - Prentice Hall of India PVT limited

Digital Systems Principles & applications

by Ronald J. Tocci Sixth Edition - Prentice Hall of India PVT limited

Kenneth J. Ayala, The 8051Microcontroller, West Publishing Company, 1991.

Muhammad Ali Mazidi,The 8051 Microcontroller and Embedded Systems, second

edition, Prentice Hall, 2005.

http://www.electrotech.com
http://www.electrotech.com/http://www.electrotech.com/http://www.electrotech.com/

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Final Mini Project Documentation