chapter 1 introduction - civimi“live”. a true robotic kit would make us closer to the...

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CHAPTER 1

INTRODUCTION

1.1 Final Project Background

For centuries the car toys species is always improvised and make people curious to have it. In

my child age I always happy to move the car toys that I have, but I ever to imagine if there is

such a car toy who can move by themselves without having problem to collide with things. My

project is a robot that could move in the open space without collide with things, moreover it

could escape from the maze or labyrinth, this robot just like a car toy but smarter and not make

the user bored. Of course this project could be improved to be a smart robot which can make a

map in the dangerous area or a SAR robot. This project is also inspired by a mice or turtle that

could escape from a house when they are out of their boxes and that often because of our little

sister or brother. This robot could be an alternative for our little sister and brother to make them

still happy.

Figure 1.1 The Turmice robot

1.2 Problem Statement

Until these days, car toys still be a favorite toys for children. A lot of us even imagine how

spectacular if we could be in that car toys. But, many of toys such as moving-robots (car toys,

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dino toys, etc) just can move forward until it stuck to the wall. The children only could feel

upset and play it with a lower imagination when the toys has been stuck to the wall. It is actually

not physically stuck (except the tank robot) because it’s motor still working. Here we could

make the imagination better for children to play with a simple-robot that can sense that accident

using microcontroller and sensor.

The microcontroller function is a brain in the robot, it is could make some logic to the robot.

The logic in this case should consist how to detect obstacle (such as wall), then the robot could

move smoothly to avoid the obstacle. The sensors here are for sensing the obstacles, it is just

like our eyes, because the robot need to see to make the action that are controlled in the

microcontroller.

Here, the robot could solved the stuck-problem without having the children feel upset again.

Figure 1.2 Robot encounter obstacle

1.3 Objective of the Project

The purpose of this project is to modify the current car toys to make the children more have

freedom to imagination and feel excited. It is to make the car toys could sense the thing that

could make them stuck. Then we give the toys sensor (Infra-Red Proximity sensor) that could

see that thing, a brain (microcontroller Arduino UNO) that could decide how to react after it see

the thing that could make it stuck, and two DC Servo Motors to run the robot in the open space.

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This final project focus on controlling the auto-robot that could dodge to stuck in the wall.

Moreover it can escaping on the simple maze in the open space. Which could be achieved by

make the robot following one of the wall (right-side or left-side). This project uses the sensor in

the right and front of the robot to make the robot could only follow the right-side of the wall.

The number of motors that used in this project is 2 (two) and separated to make it could turn

into one direction, and being controlled by motor driver and the microcontroller. The robot also

must have the logic to survive from the obstacles, which are:

a. Measure the distance to obstacle/wall, front and right

b. If the obstacle/wall is too close, the robot must turn left

c. If the wall is acceptably close, keep going forward and

d. If the wall is too far away, turn right

Here the example of how the robot could escape from a maze:

Figure 1.3 Robot escape the maze

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1.4 Scope and Limitation

In the making of this project, there are several limitations and scope that have to be applied.

Here are the scope and limitations for this project:

Scope:

The project is built in scale of laboratorium/home experiment.

Limitation:

Source code for this project is compiled using ATmega328 on Arduino UNO.

The sensor that used is DIY-Analog-Infrared Sensor, which is could only measure 0-15

cm distance (to white object), it also just have the number of decimal logic between 35-

750 (not 0-1024), even with this range we could still fulfill the objective in this project.

The intensity of light in the room must set to 9 lux.

The servo motors that used are 5VDC Motor.

The motor driver module, Arduino Motor Shield, is compatible directly with Arduino

UNO.

The maze is made of the Styrofoam-Rubber Carpet, which is the calibration is precisely

set on this matter.

1.5 Final Project Outline

The final project report consists of five chapters and is outlined as follows:

Chapter 1: Introduction. This chapter consists of problem background, Final Project statement,

Final Project objective, Final Project scope and limitation, and Final Project outline.

Chapter 2: Literature Study. This chapter describes about the component that will be used in

this final project. The description includes characteristic, work mechanism, etc. The

components consist of microcontroller ATmega 328 on Arduino UNO, Infra-Red Proximity

sensor, the 5VDC Servo Motors, Arduino Motor Shield, and LCD. Theory that will be used in

this final project also will be explained in this chapter.

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Chapter 3: Design and Implementation. This chapter delivers conceptual design and real

implementation for software and hardware. This chapter also will explain for circuitry design

and programming.

Chapter 4: Project Result and Analysis. This chapter consists of the analysis of the hardware

and software. Simulation results are examined to finally conclude the strengths and weakness

of the proposed system according to objectives in previous chapter.

Chapter 5: Conclusions and Recommendations. This chapter consists of conclusions obtained

throughout this project and recommendations for future projects.

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CHAPTER 2

LITERATURE STUDY

2.1 Preliminary Remarks

This chapter elaborates main idea and knowledge that required in the research and writing of

this final year project. All of the knowledge regarding to this project will be explain in this

chapter with objective to help reader understand the concept of this project and its supporting

elements. The objective of this project is to control the motors of the robot based on Infra-Red

Proximity Sensor reading and all of the information related to it.

The main hardware that required for this project are microcontroller ATmega328 on Arduino

UNO, Infra-Red Proximity Sensor module, 5VDC servo motor, and Arduino Motor Shield as

the motor driver`s module. The reason behind components choosing is based on availability,

ease of interfacing, and low cost price.

Section 2.2 will explains about understanding robot theory, section 2.3 will mainly explains

about the microcontroller and its features, section 2.4 is about sensor, section 2.5 explains about

the motor, section 2.6 will explains motor driver`s module Arduino Motorshield L293, and final

section; 2.7 explains about LCD LMB162AFC

2.2 Robot

Robotic is an interesting area for a lot of people, it can apply our thinking about organisms

nature to react of the world action. It pulls out our imagination to create something that nearly

“live”. A true robotic kit would make us closer to the understanding how the living-things senses

work, and how many memory (programming) can be used for specific tasks. These are the

differences between robot and a toys, the nearly living-thing with just the thing.

There are a lot of robot-things that actually do not have the robotic skills. We see a lot of robot-

shape-made of the LEGO and the others, but actually we just see the normal toys which could

not react to the specific things, it is not “live”. Things can be a robot with three characteristics:

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Input (sensor or stored in information)

Intelligent (brains – effected by the presence of a central processing unit or controller)

Actuators (output devices such as motor, application, and the other systems that can

react)

Robot would react to the specific things, this could be happen because the brain effected by the

sensor and give the order to the actuator. The brain could be represented by some controller or

in our case microcontroller. This microcontroller could control which act should be done by the

actuator if it is given some specific input of the sensor.

A robot reacts to input by judging its state with its intelligence, and passes commands to its

actuators. For example, a robot can judge where an obstacle is touching it with sensor; the input

is recorded when the sensor is tripped by the obstacle, and passed to the robot`s intelligent

processing system, which decides that hitting an obstacle is a bad idea, and moves the robot by

passing the command to the actuators.

Figure 2.1 Basic control system

2.3 Microcontroller Arduino UNO with ATmega 328

The microcontroller that used in this project is Arduino UNO within the ATmega 328, it has

function as the brain of the device. All the logic and programming is controlled on this hardware,

while it would reacts to some input and output from the others hardware. In this section we

would see how the Arduino UNO works.

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2.3.1 Arduino UNO

Figure 2.2 Arduino UNO R3 front & back

Arduino Uno is a microcontroller board based on the ATmega 328 which has 14 digital

input/output pins (6 can be used as PWM outputs), 6 analog inputs, 16 MHz ceramic resonator,

a USB connection, a power jack, an ICSP header, and a reset button. It contains everything

needed to support the microcontroller. The Arduino UNO is the latest in a series of USB Arduino

boards and the reference model for Arduino platform, then if we use this hardware we would be

has some advantages due to the up-to-date information to help we develop some devices.

Here is the features that Arduino UNO has:

Table 2.1 Arduino Features Table

Microcontroller ATmega 328 Operating Voltage 5 V

Input Voltage (recommended) 7-12 V

Input Voltage (limits) 6-20 V

Digital I/O Pins 14 (6 provide PWM output) Analog Input Pins 6

DC Current per I/O Pin 40 mA

DC Current for 3.3V Pin 50 mA

Flash Memory 32 KB (ATmega 328) of which 0.5 KB used by bootloader SRAM 2 KB (ATmega 328)

EEPROM 1 KB (ATmega 328)

Clock Speed 16 MHz

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2.3.1.1 Power sources

The power source of Arduino UNO could come through USB connection or an external power

supply, it is selected automatically. The external power supply could come from AC-to-DC

adapter or battery, the adapter could be connected by plugging a 2.1mm center –positive plug

into the board`s power jack and the battery could be connected by insert in the Gnd and Vin pin

headers of the power connector. The board can operate on an external power supply of 6 to 20

volts. If supplied less than 7V the board might be unstable, and if supplied more than 12V the

voltage regulator would overheat and could damage the board. It is recommended to use the

power sources range from 7 to 12 volts.

The power pins are as follows:

VIN the input voltage to the Arduino UNO board when it`s using an external power

source. We could supply voltage through this pin, or, if supplying voltage via the power

jack, access it through this pin.

5V this pin outputs a regulated 5V from the regulator on the board. The board could

be supplied with power either from the DC power jack (7-12V), the USB connector (5V),

or the VIN pin of the board (7-12V).

3V3 a 3.3V supply generated by the on-board regulator, maximum current draw is

50mA.

GND ground pins.

IOREF this pin on the Arduino board provides the voltage reference with which

microcontroller operates. A properly configured shield can read the IOREF pin voltage

and select the right power source or enable voltage translators on the outputs for working

with 5V or 3.3V.

2.3.1.2 Memory

The Arduino UNO board uses ATmega 328 microcontroller, it has 32 KB (with 0.5 KB used

for bootloader). It also has 2 KB of SRAM and 1 KB of EEPROM (which could be read and

written with the EEPROM library).

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Figure 2.3 Memorize size

2.3.1.3 Input and output

All of the digital pins on the board could be used as an input or output, using pinMode(),

digitalWrite(), and digitalRead() functions. They operate at 5V. Each pin could provide or

receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of

20-50 kOhms. Some pins have specialized functions:

Serial: 0 (RX) and 1 (TX) used to receive (RX) and transmit (TX) TTL serial data.

These pins are connected to the corresponding pins of the ATmega8U2 USB-to-TTL

Serial chip.

External Interrupts: 2 and 3 these pins could be configured to trigger an interrupt

on a low value.

PWM: 3, 5, 6, 9, 10, and 11 provide 8-bit PWM output with the analogWrite()

function.

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK) these pins support SPI

communication using the SPI library.

LED: 13 there is a built-in LED connected to digital pin 13. When the pin is HIGH

value, the LED is on, when the pin is LOW, it`s off.

The Arduino UNO board has 6 analog inputs, labeled A0 through A5, each of which

provide 10 bits resolution (i.e. 1024 different values). By default they measure from

ground to 5 volts, through is it possible to change the upper end of their range using the

AREF pin and the analogReference() function. Additionally, some pins have specialized

functionality:

TWI/I2C: A4 (SDA) and A5 (SCL) support TWI communication using the Wire

library.

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There are a couple of pins on the Arduino UNO board:

AREF reference voltage for the analog inputs, could be used with analogReference().

Reset bring this line LOW to reset the microcontroller.

2.3.1.4 Communication

The Arduino UNO has some of facilities to communicate with a computer, another Arduino, or

other microcontroller. The ATmega 328 has a UART TTL (5V) serial communication, which is

available on the digital pin 0 (RX) and 1 (TX). ATmega 328 on the Arduino UNO board

channels this serial communication over USB and appears as a virtual com port to the software

on the computer. The `16U2 firmware uses the standard USB COM drivers, and no external

driver is needed (even in the Windows a .inf file is required). The Arduino software includes a

serial monitor which allows simple textual data to be sent to and from the Arduino board. The

RX and TX LEDs on the board will flash when data is being transmitted through USB-to-serial

chip and USB connection to the computer (but not for serial communication on pins 0 and 1).

A SoftwareSerial library allows for serial communication on any of the Arduino UNO`s digital

pins.

The ATmega 328 also supports I2C (TWI) and SPI communication, the Arduino software

includes a Wire library to simplify communication via I2C bus and SPI library for SPI

communication.

2.3.1.5 Programming

The Arduino UNO board could be programmed with the Arduino software. The ATmega 328

on the Arduino UNO board comes pre-burned with a boot-loader that allows us to upload new

code without the use of an external hardware programmer, it communicates using the original

STK500 protocol. The Arduino UNO could also bypass the boot-loader and program the

microcontroller through the ICSP (In-Circuit Serial Programming) header.

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Figure 2.4 Example of programming the Arduino UNO with Arduino software

2.3.2 ATmega 328

Atmega328 is a single chip micro-controller created by Atmel and belongs to megaAVR series.

The ATmega 328 on Arduino UNO Board is a low power CMOS 8-bit microcontroller based

on the AVR enhanced RISC architecture, it could execute the powerful instructions in a single

clock cycle. ATmega 328 also could achieves throughputs approaching 1MIPS per MHz which

could allow the system-designer to optimize power consumption versus processing speed.

The packaging of ATmega 328 that used in this project is 28-lead PDIP, it is become the main

microcontroller of Arduino UNO, and the pin mapping of the function is as shown in figure

below.

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Figure 2.5 Arduino UNO & ATmega328 pin mapping

Which Atmega328 pin alternative function are listed in this figure below.

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Figure 2.6 ATmega328’s alternative function

The features of ATmega328 are shown in the table below.

ATmega328P Features

Feature Value

Flash 32k

EEPROM 1k

RAM 2k

I/O Pins 23

Interrupts 26

USARTS 1

USI 0

SPI 1

ADC Channels 6

Timers (8-bit) 2

Timers (16-bit) 1

PWM (8-bit) 4

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PWM (16-bit) 2

Characteristic Value

Power Consumption (approximate) 0.6mA/MHz

Maximum I/O Current (per pin) 40mA

Maximum I/O Current (all ports) 100mA(low)/150mA(high)

Maximum I/O Current (total) 200mA (PDIP)

Maximum I/O Current (total) 400mA (PDIP/QFP/MLF)

Figure 2.7 ATmega328’s features

2.4 Sensor

Sensor on robot is functioning to sense the environment within it, just like a living-thing, sensor

would give the first information to be received by the brains to determine how it should react.

Sensor on robot should be the first thing that determine as the input to the controller and one of

the important thing in the control system of the robot. To achieve the objective of traveling in

the open space first, the robot needs to sense of sight or touch, depending on the sensor

technology that we used. The robot need a sensor that could sense the distance to an obstacle, it

could be achieved by Infrared (IR) or Ultrasonic (Sonar) sensors.

Infrared sensors are type of light sensor which could sense the infrared light-level to measure it

as a distance which could be determined by given the light of infrared to the obstacle and receive

it again. Ultrasonic sensors are type of sound sensor which could sense the ultrasonic sound-

level to measure it as a distance which could be determined by given the ultrasonic sound to the

obstacle and receive it again. This phenomena is called proximity or distance detection.

Proximity sensors only detect whether or not an object is within a predetermined range from the

robot, while the distance sensors determine the actual distance between the object and the robot.

In this project the robot would use the Infrared sensors, not the Ultrasonic sensors. The Infrared

sensors much cheaper than the Ultrasonic sensors, the objective of this project also could be

achieved by the Infrared sensors only without using the Ultrasonic sensors or both. Then, on the

next explanation, we just explain about the Infrared sensors.

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2.4.1 Infrared (IR) sensors

Infrared sensor should consist of an infrared transmitter to sends out an invisible beam light into

the environment and an infrared receiver that absorbs the beam of light that is reflected back.

The angle of the reflected beam indicates the proximity of the infrared receiver to the object that

is reflecting the light. The microcontroller of the robot uses the changes in angle to measure/react

the distance of the robot from object ahead. The process of the sensors is drawed in the figure

below.

Figure 2.8 Infrared sensor`s process

2.4.1.1 IR emitter TSAL6100

TSAL6100 is an infrared 940nm emitting diode in GaAlAs/GaAs technology with high radiant

power molded in a plastic package. In this project, the IR Emitter is functioning as the

transmitter in the infrared sensor system. It would transmit the signal with certain wavelength

to be received by the IR Receiver.

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Figure 2.9 IR Transmitter in symbol

Figure 2.10 IR Transmitter in hardware

Based on its datasheet, here is the main specification of TSAL6100:

Table 2.2 TSAL6100 Main Specification

*Note: - Ie is radiant intensity - φ is angle of half intensity

- λp is peak wavelength - tr is rise time

Which the test condition under 25 °C make the characteristic such as:

COMPONENT Ie (mW/sr) φ (deg) λp (nm) tr (ns)

TSAL6100 130 ±10 940 800

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Table 2.3 TSAL6100 Basic Characteristics

PARAMETER TEST

CONDITION

SYMBOL MIN. TYP. MAX. UNIT

Forward

voltage

IF= 100 mA, tp= 20

ms

VF 1.35 1.6 V

IF= 1 A, tp= 100 μs VF 2.6 3 V

Temperature

coefficient of

VF

IF= 1 mA TKVF - 1.8 mV/K

Reverse current VR= 5 V IR 10 μA

Junction

capacitance

VR= 0 V, f = 1 MHz,

E = 0

Cj 25 pF

Radiant

intensity

IF= 100 mA, tp= 20

ms

Ie 80 130 400 mW/sr

IF= 100 mA, tp= 20

ms

Ie 650 1000 mW/sr

Radiant power IF= 100 mA, tp= 20

ms

Фe 35 mW

Temperature

coefficient of

Фe

IF= 20 mA TK Фe - 0.6 %/K

Angle of half

intensity

Φ ± 10 deg

Peak

wavelength

IF= 100 mA λp 940 nm

Spectral

bandwidth

IF= 100 mA ∆λ 50 nm

Temperature

coefficient of λp

IF= 100 mA TK λp 0.2 nm/K

Rise time IF= 100 mA tr 800 ns

Fall time IF= 100 mA tf 800 ns

Virtual source

diameter

Method: 63 %

encircled energy

D 3.7 mm

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Figure 2.11 Relative Radiant Power vs. Wavelength

The sensor has the characteristic of relative radiant power with its wavelength like in the

figure, which has peak wavelenght at 940nm.

2.4.1.2 IR receiver/phototransistor HPTB5-14D-B

HPTB5-14D-B is an infrared receiver/phototransistor, it has sensitivity wavelength between

760-1000nm. In this project, the phototransistor is functioning as the receiver in the infrared

sensor system. It would receive the signal with certain wavelength that transmitted by the IR

Emitter.

Figure 2.12 IR Receiver in hardware

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Figure 2.13 IR Receiver in symbol

Based on its datasheet, here is the main specification of HPTB5-14D-B:

Table 2.4 HPTB5-14D-B Main Specification

*Note: - λ is sensitivity wavelength - φ is angle of half intensity

- λp is peak wavelength - tr is rise time

Which the test condition under 25 °C make the characteristic such as:

Table 2.5 HPTB5-14D-B Basic Characteristics

PARAMETER SYMBOL TEST

CONDITION

MIN TYP MAX UNIT

Angle of Half

Sensitive

Φ 30 deg

Collector-

Emitter

Voltage

Vceo Ic=1mA,

Ee=0mw/cm2

30 V

Emitter-

Collector

Voltage

Veco Ic=100μA,

Ee=0mw/cm2

5 V

COMPONENT LENS

COLOR

φ (deg) λ(nm) λp (nm) tr (μs)

HPTB5-14D-B Black 30 760-1000 940 15

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Collector-

Emitter

Saturation

Voltage

Vces Ic=0.5mA,

Ib=100μA

0.4 V

Collector

Current

(Saturation)

Ic Vce=5V,

Ee=0.5mw/cm2

0.8 3.0 12 mA

Collector

Dark Current

Iceo Vce=20V,

Ee=0mw/cm2

100 nA

Rise Time Tr Vce=5V,

Ic=1mA,

RL=1000Ω

15 μS

Fall Time Tf 15 μS

Peak

Wavelength

Λp 940 nm

Sensitivity

Wavelength

Λ 760 1000 nm

Figure 2.14 Relative sensitive vs. wavelength

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The sensor has the characteristic of relative sensitive with its wavelength like in the figure,

which has range effectiveness between 760-1000nm

2.5 Motor

Two important mechanism things of a mobile robot are its motors and motor controllers. The

process of choosing a motor of a robot is a significant undertaking because the motor

ultimately selected has an impact on many other aspects of the robot. This project uses DC

Motor, which the specifications are listed as follows:

Table 2.6 5VDC Motor Specification

Voltage Ratio Current (max) Speed (max) Torque

5VDC 287:1 100mA 62rpm 3kg.cm

2.6 Arduino Motorshield L293

The motors must have “neuron” to deliver order from the microcontroller, we call this neuron

as motor driver. In this project Arduino Motorshield L293 is a package of neuron that we

need, it is a motor driver’s module that could connect directly into our microcontroller

(Arduino UNO).

Figure 2.15 Arduino Motorshield L293

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This module allows Arduino to drive two channel DC motors. It uses L293B chip which

deliveries output current up to 1A each channel. The speed control is achieved through

conventional PWM which can be obtained from Arduino’s PWM output Pin 5 and 6. The

enable/disable function of the motor control is signaled by Arduino Digital Pin 4 and 7. The

module is powered directly from Arduino.

Table 2.7 Arduino Motorshield Pin Use

Pin Function

Digital 4 Motor 2 Direction control

Digital 5 Motor 2 PWM control

Digital 6 Motor 1 PWM control

Digital 7 Motor 1 Direction control

2.6.1 L293B chip

Arduino Motorshield 293 uses L293B chip as the main driver, it is quad push-pull drivers that

capable of delivering output curents to1A per channel. Each channel is controlled by a TTL-

compatible logic input and each pair of drivers (a full bridge) is equipped with an inhibit input

which turns off all four transistors. L293B is package in 16-pin plastic DIP.

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Figure 2.16 L293B Chip

The absolute maximum ratings of L293B listed as below:

Table 2.8 Absolute Maximum Ratings of L293B

Symbol Parameter Value Unit

Vs Supply Voltage 36 V

Vss Logic Supply Voltage 36 V

Vi Input Voltage 7 V

Vinh Inhibit Voltage 7 V

Iout Peak Output Current (non-repetitive t = 5ms) 2 A

Ptot Total Power Dissipation at Tground-pins = 80 ̊C 5 W

Tstg. Tj Storage and Junction Temperature -40 to +150 ̊C

The electrical characteristics for each channel, Vs = 24V, Vss = 5V, Tamb = 25 ̊ C, unless

otherwise specified:

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Table 2.9 Electrical Characteristics of L293B

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Vs Supply Voltage Vss 36 V

Vss Logic Supply Voltage 4.5 36 V

Is Total Quiescent Supply Current

Vi = L Io = 0 Vinh = H

2 6

mA Vi = H Io = 0 Vinh =

H 16 24

Vinh = L

4

Iss Total Quiescent Logic Supply

Current

Vi = L Io = 0 Vinh = H

44 60

mA Vi = H Io = 0 Vinh =

H 16 22

Vinh = L

16 24

VIL Input Low Voltage -0.3 1.5 V

VIH Input High Voltage Vss < = 7V 2.3

Vss

V Vss > 7V 2.3 7

IIL Low Voltage Input Current VIL = 1.5V -10 µA

IIH High Voltage Input Current 2.3V 30 100 µA

VinhL Inhibit Low Voltage -0.3 1.5 V

VinhH Inhibit High Voltage Vss < = 7V 2.3

Vss

V Vss > 7V 2.3 7

IinhL Low Voltage Inhibit Current VinhL = 1.5V -30 -100 µA

IinhH High Voltage Inhibit Current 2.3V < = VinhH < = Vss – 0.6V ±10 µA

VCEsatH Source Output Saturation Voltage Io = -1A 1.4 1.8 V

VCEsatL Sink Output Saturation Voltage Io = 1A 1.2 1.8 V

tr Rise Time 0.1 to 0.9 Vo (*) 250 ns

tf Fall Time 0.9 to 0.1 Vo (*) 250 ns

ton Turn-on Delat 0.5 Vi to 0.5 Vo (*) 750 ns

toff Turn-off Delay 0.5 Vi to 0.5 Vo (*) 200 ns

Note: (*) See Figure 2.17

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Figure 2.17 Switching Timers

2.7 LCD LMB162AFC

LCD LMB 162AFC means it has 16 characters length and 2 rows. The LCD used in this project

is LMB 162AFC manufactured by TOPWAY. RS is high when it requires to send text data that

should be displayed on LCD, e.g printing a word; it is low for commanding instruction data,

such as clear screen, move cursor, and etc. E line is high, which tells it to receive data; first it

sets to low, then decide the value of RW and RS, after that bring E high logic to tells it that data

is sent, then give low logic again to E.

Here is the block diagram:

Figure 2.18 LCD Block Diagram

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This LCD consist of 16 pins which are:

Table 2.10 LCD Pin Description

Pin No. Pin name I/O Description

1 VSS Power Ground

2 VDD Power Positive power supply

3 V0 Power LCD contrast reference supply

4 RS Input Register Select

RS=HIGH: transferring display data

RS=LOW: transferring instruction data

5 R/W Input Read/Write Control bus

R/W=HIGH: read mode selected

R/W=LOW: write mode selected

6 E Input Data enable

7 DB0

I/O

Bi-directional tri-state Data bus

In 8-bit mode, DB0 ~ DB7 are in use

In 4-bit mode, DB4 ~ DB7 are in use, DB0 ~ DB3 leave open

: :

14 DB7

15 BLA Power Backlight positive supply

16 BLK Power Backlight negative supply

There are also commonly used commands and instructions for LCD, such as:

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Table 2.11 LCD Instructions

No. Instructions

Code

Function

RS

R/W

DB

7

DB

6

DB

5

DB

4

DB

3

DB

2

DB

1

DB

0

1 Clear Display 0 0 0 0 0 0 0 0 0 1 Write “20h” to DDRAM and set

DDRAM Address (AC) to “00h”

2 Return Home 0 0 0 0 0 0 0 0 1 X

Set DDRAM Address (AC) to “00h” and

return cursor to its original position if

shifted (DDRAM content are not change)

3 Entry Mode

Set 0 0 0 0 0 0 0 1 I/D S

Set cursor moving direction and specify

display shift, during data read and write

of DDRAM and CGRAM

4 Display

ON/OFF 0 0 0 0 0 0 1 D C B

D=1, display on; D=0, display off

C=1, cursor on; C=1, cursor off

B=1, cursor blinking on; B=0, cursor

blinking off

5 Cursor or

Display Shift 0 0 0 0 0 1 S/C R/L X X Move the cursor or shift the display

6 Function Set 0 0 0 0 1 DL N F X X

DL=1, 8-bit; DL=0, 4-bit

N=1, 2-line; N=0, 1-line

F=1, 5x11 dots; F=0, 5x8 dots

7 Set CGRAM

Address 0 0 0 1 AC5 AC4 AC3 AC2 AC1 AC0 Set CGRAM Address in address counter

8 Set DDRAM

Address 0 0 1 AC6 AC5 AC4 AC3 AC2 AC1 AC0 Set DDRAM Address in address counter

9

Read Busy

Flag &

Address

0 1 BF AC6 AC5 AC4 AC3 AC2 AC1 AC0

Check the system status and get the

address counter content (AC6 ~ AC0).

BF=1, busy; BF=0, ready

10 Write data to

RAM 1 0 D7 D6 D5 D4 D3 D2 D1 D0

Write the data into internal RAM, where

the address counter pointing at.

11 Read data

from RAM 1 1 D7 D6 D5 D4 D3 D2 D1 D0

Read the data from internal RAM, where

the address counter pointing at.

29

CHAPTER 3

DESIGN AND IMPLEMENTATION


These chapters will mainly talks about implementation and design of the desired project. All of

the designs written in this chapter are based on theories and knowledge that been gathered by

the author. The designs that will be elaborated in this chapter are circuitries of motor driver’s

module (Arduino Motorshield L293), sensors, and LCD to the microcontroller.

3.2 Hardware Design

The main hardware consisting of microcontroller unit, motor driver’s module, sensor, LCD, and

motor. The overall of the project is pictured in figure below.

Figure 3.1 Final project block diagram

Microcontroller acts as processor that will compile the inputs and give outputs regarding to

several perimeters set for this project.

30

Firstly 9V battery is converted into 5Vdc by the Arduino, then 5Vdc powers the entire hardware

(sensors, driver motor’s module, motors and LCD). The arduino also convert the analog signal

from sensors into the digital signal (like ADC), so it can be read in the microcontroller. Since

Arduino UNO have internal ADC, then external ADC is not required to fulfill the purpose of

the project. By converting the analog signal becomes digital, LCD can display the sensor

measurement through ADC. The value of this ADC later on will be divided into few ranges to

determine different motor’s speed with respect to sensor reading.

The ADC value would be processed in the program of the arduino regarding to sensor reading;

in certain value range, the arduino and driver motor’s module will response whether to makes

the motor working on full, half, or less power. The robot working is done by software/ program

that will be explained in this chapter.

3.2.1 Infrared-sensor`s module

Infrared-sensor`s module is a circuitry that will read and write signal to the microcontroller so

the microcontroller could choose the action in the programs. This project use a pair (two)

Infrared-sensor`s module to fulfill the objective, the sensors location are in the right-side and

front-side of the robot. This sensor has 3 pins; Vcc, Gnd, and Vout pins, where the Vcc and Gnd

are connected to the Vcc and Gnd pins of microcontroller, and Vout pin is connected to the

analog input pins (0, 1) in the microcontroller.

Figure 3.2 Infrared-sensor`s module circuitry

31

The IR Emitter TSAL 6100 (D1) transmit the signal to the wall/obstacles, the wall/obstacles

reflect the signal back and the signal is received by IR Receiver/Phototransistor HPTB5-14D-

B (T1). The IR Emitter has the characteristic of relative radiant intensity with angular

displacement like in the figure, which has the most effective radiance at 0° (perpendicular),

while the IR Receiver sensor has the characteristic of relative radiant sensitivity with angular

displacement like in the figure, which has the most sensitive radiance at -15° until 15°

(30deg).

.

Figure 3.3 Relative Radiant Intensity vs. Angular Displacement IR Transmitter & Receiver

After the IR Receiver receives the analog signal, the signal is converted to digital in the Arduino

UNO, so it could be read and processed in the microcontroller.

3.2.2 Arduino Motorshield L293

Arduino Motorshield L293 consist the L293B chip, the driver means it is working to drive the

current to control the movement of the motors, it consist H-Bridge circuit as the basic circuit.

The speed control is achieved through conventional PWM which can be obtained from

Arduino’s PWM output Pin 5 and 6. The enable/disable function of the motor control is signalled

32

by Arduino Digital Pin 4 and 7. The driver receive the command from Arduino to react as the

program written. The code/program would be explained in the software session.

Figure 3.4 L293B Block Diagram

3.2.2.1 H-Bridge circuit

The H-Bridge circuit is commonly used to control DC Motors, the idea is that five electrical

The L293B works as the figure and table below:

Figure 3.5 DC motor controls

33

Table 3.1 DC Motor Controls Description

Inputs Function

Vinh = H C = H; D = L Turn Right

C = L; D = H Turn Left

C = D Fast Motor Stop

Vinh = L C = X; D = X Free Running Motor Stop

*Note: H = High, L = Low, X = Don’t Care

3.2.3 LCD LMB162AFC

This project use LCD LMB162AFC, it is in 4-bit mode, because the characters that the author

used just alphabet and numerical. The LCD has 16X2 characters to displays value of ADC

relating to sensor reading. It is useful to provide that information, since the controller works at

certain ranges of ADC value. By displaying it, it will make the observation easier.

The connection of the LCD is assembled this way:

Table 3.2 LCD Pin Description

LCD Pins Arduino Pins Potentiometer Pins Function

1 Gnd Gnd Logic

2 Vcc Vcc

3 Vout Contrast

4 8

Register Select (RS) *Microcontroller tells the LCD whether it wants to display the data

5 Gnd Not used

6 13

Enable (E) *Microcontroller tells the LCD when data is ready for reading

11 9 DB4

12 10 DB5 Data Pins

13 11 DB6

14 12 DB7

15 Vcc Backlight

16 Gnd

34

3.3 Software Design

For programming purpose, this project use Arduino language, which has the C language as the

basic. The Arduino language compiler that’s used is Arduino IDE. This sub-chapter will

explains the usage of the software to utilize components, such as imported library, declaration

of variable, setting up of the variable, and the looping programs that required to fulfill the

objective of this project.

3.3.1 Imported library

The library is used quite common when creating Arduino based device. It is usually used to

make it easier to develop the program. The library that used in this project is LiquidCrystal, the

function is to make it easier to connect the LCD to Arduino board, the imported library is written

this way:

// include the library code:

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins

LiquidCrystal lcd(13, 8, 9, 10, 11, 12);

This part of program means pins 8, 9, 10, 11, 12, and 13 of the LCD are used to connect to the

Arduino board.

3.3.2 Declaration of variable

This part of program means pins 4, 5, 6, and 7 of the Arduino are used to connect to the Arduino

Motorshield L293. This part used int as the declaration, because the variable consists of

numerical data, the declaration is written this way:

int motorright = 6; // the PWM pin

int motorleft = 5; // the PWM pin

int arahmotorleft = 4; //direction control pin

35

int arahmotorright = 7; //direction control pin

The pin 5 and 6 are PWM pins, it means the Arduino board receive the analog signal (numerical)

in these pins. The signal that’s received by Arduino board is used to control the speed of the

motors; which pin 5 is connected to right-side motor, and pin 6 is connected to the left-side

motor. The pin 4 and 7 are digital pins, it means the Arduino board receive the digital signal in

these pins. The signal that’s received by Arduino board is used to control the direction of the

motors (H-bridge circuit); which pin 4 controls the left-side motor, and pin 7 controls the right-

side motor.

3.3.3 Setting-up the variables

This part is used to set up the variables, so the program could identify the variables that are used.

To enables this set up there must be a function (main) called void setup, the set-up is written as:

void setup() {

// initialize the Arduino Motorshield L293 pin as an output:

pinMode(motorleft, OUTPUT);

pinMode(motorright, OUTPUT);

pinMode(arahmotorleft, OUTPUT);

pinMode(arahmotorright, OUTPUT);

}

The pinMode is a function to set the variables in the current pin as inputs or outputs, where

OUTPUT is a declaration to the program that the variable is set as an output.

3.3.4 The looping/main programs

This looping part in the program is signed by void loop, the function means that the program is

always looping until it is stopped (by power or program).

void loop(){

36

// read the state of the pushbutton value:

PrintLCD();

Fuzzy();

delay(100);

}

The function above will be called in the main program. Before command and data function can

be use, the following initialization for command and data should be done like that. PrintLCD

and Fuzzy are the variables that will looping in this program. The delay function is to limit the

looping (not too fast and slow), which is set to 100ms.

3.3.4.1 PrintLCD program

This part of looping is to set the display in the LCD based on the sensor signals that received by

the Arduino board. The basic is to set void to PrintLCD, which means the LCD start to printing.

The program should be done as:

void PrintLCD(){

// lcd printing

String stringfront = String (analogRead(0));

String stringright = String (analogRead(1));

lcd.begin (16, 2); //initiate the LCD 16×2

lcd.print ("SENSOR F = " + stringfront);

lcd.setCursor (0, 1); //change the cursor line

lcd.print ("SENSOR R = " + stringright);

delay(100);

}

37

String is a function to declare an array of type char and null-terminate it, this function also could

print the data into the LCD, but it could not consist the variables that would be used as equation

(for example: m*n). The method that used by this function is reading subsequent bytes of

memory continuously, string+x would be a formula in this function. The analogRead function

is to read the analog signal input in the Arduino board, which are given by analog pin 0 and 1

and has a value from 0-1023 (ADC). The algorithm of LCD in this project is:

Set the PrintLCD as a part of looping program

Select the variable that’s used in String function.

Select the analog signal input in the String function , in this case is analog pin 0 and 1.

Initiate the LCD 16X2, signed by lcd.begin (16, 2);

Read the value of analog signal in pin 0 and 1 in analog pin so it could printed in the

LCD, the function is analogRead.

Print the value of sensor front (analog pin 0) continuously in the first line (0), signed by


Change the cursor line from (0) to (1) to print the next variable, signed by lcd.setCursor

(0, 1);

Print the value of sensor right (analog pin 1) continuously in the second line (1), signed

by lcd.print ("SENSOR R = " + stringright);

Wait 100ms to response to the next signal value, signed by delay(100);.

The value range of this ADC that printed in the LCD is from 0-1024 (0-15cm).

3.3.4.2 Fuzzy program

The other looping variable is fuzzy, which is signed by void Fuzzy. In this part the program

would set and give logic in the Arduino board to the Arduino Motorshield and motors. The

program consist the code of fuzzy logic to fulfill the objective in this project, which are how to

avoid the obstacle and always move smoothly in the right-side. This code also require the analog

signal from the sensors as the input in the Arduino board. The code is written as follows,

void Fuzzy(){

int sensorStatefront = analogRead(0); // variable for reading the pushbutton status

38

int sensorStateright = analogRead(1);

digitalWrite(arahmotorleft, HIGH);

digitalWrite(arahmotorright, HIGH);

}

if (sensorStatefront > 700){ //undetect, turn to the right-side

if (sensorStateright > 680){

analogWrite(motorright, 30);

analogWrite(motorleft, 90);

}

if (sensorStateright < 650){



}




}




}




}

}

if (sensorStatefront < 750){ //obstacle on the front, turn left


39


}

if (sensorStatefront < 730){



}




}

}

}

This part uses the int function as a declaration that the input variable is numerical and should be

read in the analog pin 0 and 1 (automatically convert to digital, like ADC), signed by analogRead

function. This function could consist an equation variables (for example: m*n). The variables

are sensorStatefront (0) and sensorStateright (1). This part of program also consist the

digitalWrite to command that the variables should be written in any state; HIGH and LOW,

while the HIGH state means the output would has 5V voltage. The algorithm of this part of

programs should be:

Set the Fuzzy variable as a part of looping program.

Declare the variables that are used in this Fuzzy part, it get the inputs from analog pin 0

and 1, signed by int sensorStatefront = analogRead(0); and int sensorStateright =

analogRead(1);

Set the variables digitally of arahmotorleft and arahmotorright into HIGH, signed by

digitalWrite(arahmotorleft, HIGH); and digitalWrite(arahmotorright, HIGH);

Set the condition and command in the program using if function as the condition and

analogWrite as the command to set the speed of motors.

The if function is read the condition from the input of signals (ADC) that are read by

sensors (sensorStatefront & sensorStateright), the range of ADC is from 0 to 1023

40

because the ADC has 10-bit resolution (based on the ATMega328 datasheet), it represent

the distance to the object (0-15cm).

The analogWrite function is commanding the right-side and left-side motors depends on

the condition the robot is faced, the range of speed value in the program is 0-255 because

the Arduino Motorshield use PWM pin and the PWM output of the Arduino UNO is 8-

bit and has a 980Hz frequency (pin 5 and 6), it represent the speed of the motor (stop,

slow, fast).

The code that is used to fulfill the objective of this project is written as:





}




}




}




}




}

}

41

if (sensorStatefront < 750){ //obstacle on the front, turn left



}




}




}

}

}

The code above is get by research on the commanding function based on the trial-error.

This program works in certain condition such as the intensity of the light (it effecting

much), the color and basic material of the obstacle (in this project author uses light-green

Semi-Styrofoam carpet), and stale power supply (full charge 9V battery rechargeable).

42

3.3.5 Project algorithm

Here is the flow chart of project algorithm:

Figure 3.6 Flow chart of the project

Firstly, initialization is done by software as explained above. Then the sensors send the data to

microcontroller, the analog signal is converted into digital in the microcontroller automatically.

43

After that the LCD would show the value of ADC on the front-side and right-side of the sensors.

Function void loop(), always loop the Fuzzy and PrintLCD variables, while PrintLCD and

Fuzzy always processed linearly. The Fuzzy program is the main program to control the motors

through motor driver, it would check the condition by the if function and give the command

based on the condition by the analogWrite function. The objective in this program is to make

the robot follow the right-side of the maze and escape it. The end of the process is when the

robot made a move by the program, then the process is returned to check and converting ADC

value again.

44

CHAPTER 4

PROJECT RESULT AND ANALYSIS


This chapter contains final result of the project, and analysis from author’s point of view during

working on this project.

4.2 Project Result

The figures shown below are the appearance of the device.

Figure 4.1 The right-side of the device part 1

45

Figure 4.2 The right-side of the device part 2

Figure 4.3 The up-side of the device

46

Figure 4.4 The Infrared sensors

Figure 4.5 LCD shows ADC value

47

Figure 4.6 Arduino Motorshield as the motor driver’s module

Figure 4.7 The simple maze

48

The project is tested in the room that has 9 lux light intensity, because the infrared sensor is very

sensitive to the change of light, the author should tested it in the space that has stable lightness.

The light intensity is measured by an application called CPU-Z, it is one of the android

application that reads the sensors on the smartphone Sony Xperia V.

Figure 4.8 Light intensity test

The LCD would read the ADC data in the sensors, it makes the author easier to read and observes

to make sure the project is fulfill the objective. The ADC data that author`s tested are limited at

0 to 15 cm (min-max) and in the room that has 9 lux light intensity. Theoretically, the ADC

values versus distance would make a linear graph, but the author has facing a differences of

value while tested and here are the result:

Table 4.1 ADC of Front-Side Sensor

Distance (cm) ADC Tested ADC Theoretically

0 35 0

1 45 68.2

2 55 136.4

3 175 204.6

4 435 272.8

5 550 341

6 625 409.2

7 665 477.4

8 705 545.6

49

9 735 613.8

10 750 682

11 755 750.2

12 775 818.4

13 780 886.6

14 785 954.8

15 790 1023

From table above, the following graph can be obtained:

Figure 4.9 Front-side sensor`s ADC comparison

The right-side sensor has different result as follows:

Table 4.2 ADC of Right-Side Sensor

Distance (cm) ADC Tested ADC Theoretically

0 35 0

1 45 68.2

2 50 136.4

3 210 204.6

4 440 272.8

5 545 341

6 590 409.2

50

7 645 477.4

8 660 545.6

9 690 613.8

10 700 682

11 710 750.2

12 720 818.4

13 725 886.6

14 730 954.8

15 740 1023

The graph also has different result:

Figure 4.10 Right-side sensor’s ADC comparison

The value of ADC could be obtained theoretically from this calculation:

�� = ��(��)

�� × �� (��. �� ) (4.1)

51

The voltage in the sensors are the input of ADC, the voltage data that author`s tested are limited

at 0 to 15 cm (min-max) and in the room that has 9 lux light intensity. Theoretically, the voltage

values versus distance would make a linear graph, but the author has facing a differences of

value while tested and here are the result:

Table 4.3 Front-Side Sensor’s Voltage

Distance (cm) Voltage Tested (Voltage) Voltage Theoretically (Voltage)

0 0.17 0.00

1 0.22 0.33

2 0.27 0.67

3 0.86 1.00

4 2.13 1.33

5 2.69 1.67

6 3.05 2.00

7 3.25 2.33

8 3.45 2.67

9 3.59 3.00

10 3.67 3.33

11 3.69 3.67

12 3.79 4.00

13 3.81 4.33

14 3.84 4.67

15 3.86 5.00

From table above, the following graph can be obtained:

52

Figure 4.11 Front-side sensor`s voltage comparison

The right-side sensor has different result as follows:

Table 4.4 Right-Side Sensor’s Voltage

Distance (cm) Voltage Tested (Volt) Voltage Theoretically (Volt)

0 0.17 0.00

1 0.22 0.33

2 0.24 0.67

3 1.03 1.00

4 2.15 1.33

5 2.66 1.67

6 2.88 2.00

7 3.15 2.33

8 3.23 2.67

9 3.37 3.00

10 3.42 3.33

11 3.47 3.67

12 3.52 4.00

13 3.54 4.33

14 3.57 4.67

53

15 3.62 5.00

The graph also has different result:

Figure 4.12 Right-side sensor’s voltage comparison

The voltage values could be obtained theoretically from this calculation:

� = ��(��)

��(�� . ��) × �� (4.2)

After the ADC is read by the microcontroller, it would trigger the command to PWM to control

the movement of the device. The PWM (Pulse-width modulation) controls the speed of the

motors, which could cause the device to move straight forward, turn right, and turn left. Briefly,

a PWM signal is a digital square wave, where the frequency is constant, but that fraction of the

time of the signal is on (duty cycle) can be varied between 0 and 100% depends on the PWM

signal that is written on the motor driver. The PWM signal’s range in the Arduino IDE is

between 0 and 255, it is linearly to the duty cycle of its PWM. Here is the data that collected

during the test:

0.00

1.00

2.00

3.00

4.00

5.00

6.00

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Vo

ltag

e

Distance (cm)

Data Comparison

Voltage (tested) Voltage (theoretically)

54

Figure 4.13 PWM read in oscilloscope

The PWM test using oscilloscope in the channel 1 with 0.1ms time/division and 5 volts/division.

After collecting some data of PWM, the duty cycle could be read from the oscilloscope. The

way to read it is seeing the width of HIGH pulse then divided it by 10 (the full duty cycle in this

PWM read) and multiply it by 100%.

Table 4.5 Duty Cycle Data

ADC PWM Duty Cycle Tested (%) Duty Cycle Theoretically (%)

Front Right Left Right Left Right Left Right

0-679 X 0 75 0 30 0.00 29.41

680-729 X 15 70 3 25 5.88 27.45

730-749 X 30 80 11 30 11.76 31.37

>750

0-379 60 80 22 26 23.53 31.37

380-489 70 70 25 25 27.45 27.45

490-559 70 50 26 18 27.45 19.61

600-649 80 40 29 14 31.37 15.69

>650 90 30 32 12 35.29 11.76

The table above shows all of the data that connected with PWM data (ADC as the input, then

the PWM, and duty cycle of the PWM itself). There is such differences results while the author’s

tested with the results by calculation. The differences could see in the figure below:

55

Figure 4.14 Left-side motor`s duty cycle comparison

Figure 4.15 Right-side motor`s duty cycle comparison

The duty cycle could be measured from reading the wave in the oscilloscope, but theoretically

the duty cycle values could be obtained from this calculation:

�� =��

�� (�� ) × ��% (4.3)

56

The differences could be showed like in the table below:

Table 4.6 Differences of the Duty Cycles on the Left Motor (Pin 5)

Duty Cycle Left Tested Duty Cycle Left Theoretically Differences (%)

0 0.00 0.00

3 5.88 49.00

11 11.76 6.50

22 23.53 6.50

25 27.45 8.93

26 27.45 5.29

29 31.37 7.56

32 35.29 9.33

Table 4.7 Differences of the Duty Cycles on the Right Motor (Pin6)

Duty Cycle Right Tested Duty Cycle Right Theoretically Differences

(%)

30 29.41 2.00

25 27.45 8.93

30 31.37 4.38

26 31.37 17.13

25 27.45 8.93

18 19.61 8.20

14 15.69 10.75

12 11.76 2.00

The data above is come from below equation:

�� = �� − ��

�� × ��% (4.4)

The fuzzy-part of the program contain delay, the delay has an effect to the success rate of the

results. The part of the program is written as:

57

void loop(){ // the function to loop the variables in the program

PrintLCD();

Fuzzy();

delay(100); // the looping delay that effecting Fuzzy and PrintLCD function

}

This part of the program is set the variables that would looping, one of the variable is Fuzzy

function which is contain the command to set PWM to the motor driver based on the ADC

condition. In the end of this part of the program, there is delay function, it has function to give

a break between the looping code/program. The number of the delay above is 100 which means

there will be a 100ms delay time before the looping program is starting again. In fact, the delay

value is give such an effect to the success rate of the result while on the site. By testing each of

delay for 9 times, here are the average of result:

Table 4.8 Fuzzy Delay vs Success Rate

Fuzzy Delay (ms) Result Success Rate (%) Note

100 √ 100 Stable & Success

200 √ 100 Stable & Success

300 √ 66.66 Unstable & Success

400 × 33.33 Unstable & Fail

500 × 0 Fail

600 × 0 Fail

700 × 0 Fail

The device could fulfill the objective with stable movement at 100 and 200 millisecond delay,

at 300 millisecond it still success but not stable (above 50%), while at the point of 400

millisecond the device start to fail, it means the success rate is below 50%.

From the above table, the graph could be obtained:

58

Figure 4.16 Fuzzy delay and success rate graph

4.3 Analysis

As can be seen in data above, slight differences can occur and possible because of several

aspects:

Changes of the light intensity

Misreading the measurement devices (oscilloscope).

Error tollerance from measurement devices, and electrical components itself.

Several approaches are done during the making of this project.

Number correction.

4.4 Discussion

When working on this project, author find several problems. To overcome the problems, author

seek aid from final project supervisor, and also other reliable references. The major problems

that faced by author will be elaborated below.

Infrared sensors are produce different ADC value in the meantime, it possibly because the light

intensity of the room is changing while the author tested it. Since the environment on the tested

59

site just has a stable light intensity in the night, then the author should tested it after 6 pm. Even

though sometimes the problem still occur but not as intense as in the noon.

The ADC shows different value while tested with the calculation. It shows 35 when it must be

0 at 0 centimeters (minimal value), it also shows 740 and 790 when it must be 1023 at 15

centimeters (maximal value). It means the sensors has a little voltage at minimum distance and

less than expected voltage at maximum distance, like in the Figure 4.7 until 4.10.

The duty cycle of PWM reading on the oscilloscope also shows little differences with the

theoretical calculation results. It shows the differences is below 10 percent except 3 values, it

could be caused by misreading of the oscilloscope or the device itself.

The oscillator the author`s used is an analog one, it is could cause misreading because there is

no numerical value on the display (not like the digital one). It also old and not calibrated yet

(said the lab assistant), because the lab would calibrate it in the next week or month. Then the

reading process of the oscilloscope could cause some differences value than the author`s

expected.

The power supply (9V battery rechargeable) is run out quickly. It is could give some effect to

the device since the current and voltage could not stable while it is running out, the effect is the

motor’s speed is decreased much and the sensors also has unstable output.

60

CHAPTER 5

CONCLUSION AND RECOMMENDATIONS

5.1 Conclusion

This project provides a robot that could escape a simple maze in the open space by read and

follows the right-side of the maze`s wall. The inputs are come from ADC value of Infrared

Proximity sensors which is set on the right-side and front-side of the robot. The sensors could

give a stable output (ADC) where the space has stable light, the light also must has 9 lux light

intensity. The result of this project is showing that the car toys could be modified into an

automatic robot, not just by remote control. This project could be improved a lot to make a SAR

robot, or map making robot by adding some sensors and function again.

5.2 Recommendations

This project is met its objective, which is escape the simple maze in the open space. However,

this project can be improved and expanded further by:

Replace the sensors to the ultrasonic/sonar sensors to make the ADC is more stable and

not effected by the light intensity.

Adding several sensors to get more function.

Replace the power supply or in this case battery that is not running out quickly.

Replace all of the wiring into full PCB or at least always minimize wire usage, to avoid

project malfunctioning caused by defected cable/wire.

That are some of the possible suggestions to make this project better.

61

REFERENCES

[1] Saul Ribai A.P., “Wall Following Robot,” Bachelor of Electrical Engineering. Project

report, Dept. Elect. Eng., Kolej Univ. Tek. Kebangsaan Malaysia. 2006.

[2] R.E. Kalman., On The General Theory of Control Systems, 1960, pp. 481-492.

[3] F. Schubert. Arduino UNO. [Online]. Available: www.googledocs.com [Oct 10, 2012].

[4] Wikipedia.com. “Control Theory” Available :

http://www.wikipedia.com/control-theory.htm, 2000 [December 2013]

[5] Robotwiki.com. “Arduino Motorshield L293” Available :

http://www.robotwiki.com/arduino-motor-shield-l293.htm, 2009 [December 2013]

[6] Adafruit.com. “Overview Character LCD” Available :

http://www.adafruit.com/overview-character-lcd.htm. 2009 [Desember 2013]

[7] Arduino.cc. “Arduino UNO Schematic” Available :

http://arduino.cc/en/arduino-uno-schematic.php, [January 2012]

[8] Atmel.com. “ATMega328 data sheet” Available :

http://atmel.com/datasheet/ATMega328.pdf, 2009 [January 2013]

[9] Vishay.com. “TSAL6100 data sheet” Available :

http://vishay.com/datasheet/TSAL6100.pdf, [October 2012]

[10] Hueyjann.com. “HPTB5-14D-B data sheet” Available :

http://hueyjann.com/datasheet/hptb5-14d-b.pdf, 2010 [February 2013]

[11] Sgsthomson.com. “L239B data sheet” Available :

http://sgsthomson.com/microelectronics/L293B.pdf, 1994 [January 2013]

[12] Topwaysz.com. “LMB162AFC Manual Rev0.1.” Available :

http://topwaysz.com/manual/LMB162AFC-manual-rev.pdf, 2002 [December 2012]

[13] Digiware.com. “TOPWAY 16x2 LCD data sheet.” Available :

https://docs.google.com/file/d/0BzkNNhuEnaF-

MjYxMTIxNzYtNmQ2Yi00MzM4LWJhNGUtNzNjOWRlY2FiZGI5/edit?pli=1&hl=

en#, [January 2013]

[14] Arduino.cc. “AnalogRead” Available :

http://arduino.cc/learn/function/analog-read.htm, 2010 [March 2013]

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[15] Arduino.cc. “AnalogWrite” Available :

http://arduino.cc/learn/function/analog-write.htm, 2010 [March 2013]

[16] Arduino.cc. “DigitalWrite” Available :

http://arduino.cc/learn/function/digital-write.htm, 2010 [March 2013]

[17] Arduino.cc. “LiquidCrystalBegin” Available :

http://arduino.cc/learn/function/liquid-crystal-begin.htm, 2010 [March 2013]

[18] Arduino.cc. “LiquidCrystalSetCursor” Available :

http://arduino.cc/learn/liquid-crystal-set-cursor.htm, 2010 [March 2013]

[19] Arduino.cc. “PWM” Available :

http://arduino.cc/learn/function/PWM.htm, 2010 [March 2013]

[20] Arduino.cc. “SecretsOfArduinoPWM” Available :

http://arduino.cc/learn/function/secrets-of-arduino-pwm.htm, 2010 [March 2013]

[21] Arduino.cc. “String” Available :

http://arduino.cc/learn/function/String.htm, 2010 [March 2013]

[22] Wikipedia.com. “H-Bridge” Available :

http://wikipedia.com/h-bridge.htm, 2012 [March 2013]

63

APPENDIX A

SOURCE CODE

// include the library code:

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins

LiquidCrystal lcd(13, 8, 9, 10, 11, 12);

int motorright = 6; // the PWM pin

int motorleft = 5; // the PWM pin

int arahmotorleft = 4; //direction control pin

int arahmotorright = 7; //direction control pin

void setup() {

// initialize the Arduino Motorshield L293 pin as an output:

pinMode(motorleft, OUTPUT);

pinMode(motorright, OUTPUT);

pinMode(arahmotorleft, OUTPUT);

Appendix A: Source code

64

pinMode(arahmotorright, OUTPUT);

}

void loop(){

// read the state of the pushbutton value:

PrintLCD();

Fuzzy();

delay(100);

}

void PrintLCD(){

// lcd printing

String stringfront = String (analogRead(0));

String stringright = String (analogRead(1));

lcd.begin (16, 2); //inisialisasi LCD 16×2


65

lcd.setCursor (0, 1); //pindah kursor

lcd.print ("SENSOR R = " + stringright);

delay(100);

}

void Fuzzy(){

int sensorStatefront = analogRead(0); // variable for reading the pushbutton status

int sensorStateright = analogRead(1);

digitalWrite(arahmotorleft, HIGH);

digitalWrite(arahmotorright, HIGH);





}



66


}




}




}




}

}




67

}




}




}

}

68

APPENDIX B

DATA COLLECTION

Table B.1 Data collection after 9 times observation

Fuzzy

Delay (ms)

Result Success

Rate (%) Note

1st 2nd 3rd 4th 5th 6th 7th 8th 9th

100 √ √ √ √ √ √ √ √ √ 100 Stable & Success

200 √ √ √ √ √ √ √ √ √ 100 Stable & Success

300 √ √ √ √ √ √ × × × 66.66 Unstable & Success

400 √ √ √ × × × × × × 33.33 Unstable & Fail

500 × × × × × × × × × 0 Fail

600 × × × × × × × × × 0 Fail

700 × × × × × × × × × 0 Fail

Figure B.1 Motor left (5) PWM read (0-679, X)

Appendix B: Data collection

69

Figure B.2 Motor right (6) PWM read (0-679, X)


70



71


Figure B.7 Motor left (5) PWM read (>700, 0-379)

72

Figure B.8 Motor right (6) PWM read (>700, 0-379)


73



74



75


Figure B.15 Motor left (5) PWM read (>700, >650)

Figure B.16 Motor right (6) PWM read (>700, >650)

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