Final Write Up_1

7/27/2019 Final Write Up_1

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ABSTRACT

Our group made this device to help and developed miniaturized, wearable sensor device

that will enhance the safety of persons who are visually impaired. The device warns the users

when they are about to hit an obstacle at head level and on their path. The sensor which uses two

ultrasonic transducers for obstacle localization which is attached at the users cup and the other

sensor can be worn at the wrist.

Care of each developer was performed in making this device to optimize the functionality

of the work in terms of accuracy and detection.


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CHAPTER I

INTRODUCTION

This project deals with creating a device that will help visually impaired people so that

they will have an additional security and comfort in doing their everyday task. This device is

made of ultrasonic transducers, dc vibrating motor that will give signals when there is a possible

collision and an arduino compatible board.

The ultrasonic sensor releases short burst of ultrasonic sound wave and then outputs a

pulse as soon as a returning echo is detected. The distance range detectable by the ultrasonicsensor (US-100) is 2cm350cm but we have set this to 100cm or 1m. As soon as an obstacle is

detected the ultrasonic sensor will send signals to the arduino board and this will read the data

and will drive the dc vibrating motor to vibrate and to the buzzer to give signal to the visually

impaired user that he/she is about to hit an obstacle.

1.1BACKGROUND OF STUDY

It is estimated that half a million of people in the Philippines are blind and this is number

is very surprising. By far, the leading cause of blindness among adults in the Philippines is

cataract accounting for around 400,000 cases. The treatment for cataract is simple and effective

but it is not readily available and affordable for those who are living in some rural areas and

remote places.

One hundred children lose their sight every week and almost half of these are either

treatable or preventable. Poor nutrition, measles and premature birth are the leading causes of

blindness of children.


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This are certain facts that presents the state and numbers of visually impaired individuals

in the Philippines and even it is treatable by the help of modern technology and medicine, not all

individuals have the ability to have their proper treatment.

Some untreated visually impaired individuals uses canes, dog guide and some are just

handled and guided by their relative. But the two things mentioned have certain limitations in

preventing collisions. Using canes does not protect individuals in obstacles at head level while

some dog guide users experience traumatic incidences.

Being visually impaired is a difficult situation, so our group developed this device as an

additional help to those who are visually impaired and to give them the assurance of secured

walk outside and to protect them from head level obstacles.

1.2DESCRIPTION OF THE PROJECT

This device will protect individuals with head level obstacles and obstacles on their path.

With respect to existing Electronic Travel Aids, this device is minimalistic and can be

comfortably worn by individuals. This device adds protection to individuals who uses canes

because cane cannot protect blind users against head level obstacles such as tree branches, etc.

The device will be worn using cup and the other sensor is attached to the individuals

wrist and the circuit board can be attached to the users arm. As opposed to Electronic Travel

Aids using ultrasonic sensors, infrared lights and GPS technology, this device provides a

feedback just enough to ensure that the user can avoid a potentially painful collision. ETAs

using infrared lights is cheap but not that accurate specially when walking outside with the

presence of lights. GPS technology was also used in other travel aids but this is too expensive for

individuals who are living in remote places.

The device we made is affordable by the individuals in rural and remote places but the

accuracy and functionality of the device is same with some existing travel aids.


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1.3FUNCTIONS

The main function of the device is to give signal to the visually impaired users when an

obstacle is on their path. The sensor is attached to the users cup to protect the wearers head

against collision.

The device we made is divided into two systems that work like human body. The heart of

the device us the ultrasonic sensor that would be used as a distance detector, the sensor releases

sound waves and then sends a pulse as soon as a returning echo is detected. As the returning

echo was detected, it will be sent to the arduino compatible board. The arduino compatible board

is primarily made up of Atmel Mega 328, and this serves as the brain of the system. The arduino

reads the data sent by the sensor and when the sensor detects a possible obstacle, this will send

enough signals to energize the dc vibrating motor and buzzer to give an alarm to the user.

1.4ON OUR FIRST PROJECT

This project deals with creating a device that will help visually impaired people so that

they will have an additional security and comfort in doing their everyday task. This device is

made of ultrasonic transducers, op amp, decade counter and earphone that will give signals

when there is a possible collision at head and eye level obstacles.

The ultrasonic sensor releases short burst of ultrasonic sound wave and then outputs a

pulse as soon as a returning echo is detected. The distance range detectable by the device is 2cm

350cm. As soon as an obstacle is detected the ultrasonic sensor will send signals to the receiver

transducer. The 40 kHz ultrasonic signal are converted into 40 kHz electric signals by the

receiver and amplified by transistor T3 and T4. The device have a decade counter IC4017 to

make 40 kHz be converted to 4 kHz signal which is fed to op-amp IC741 which is wired as an

earphone amplifier to give signal to the visually impaired user.


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The main function of the device is to give signal to the visually impaired users when an

obstacle is on their path. The sensor is attached to the users eyeglass to protect individuals head

and eye against collision.

The main part of the device is the ultrasonic sensor (US-100), this works at the frequency

of 40 kHz and it is temperature compensated so it gives an accurate signal even there is a change

with the environment temperature. The ultrasonic sensor is divided into two parts the transmitter

which emits 40 kHz sound and receiver which receives 40 kHz sound and converts it into

electrical variation of the same frequency.

The device also has certain transistors T1 and T2 which serves as a 40 kHz oscillator.

When there is an obstruction detected in front of ultrasonic transmitter, some signals will be

reflected back and sensed by the ultrasonic receiver. This 40 kHz ultrasonic signal will be

converted into 40 kHz electrical signals by the receiver and then amplified by transistors T3 and

T4.

To make an audible sound out of 40 kHz electric signal, we put a decade counter IC4017

(IC1) which is a frequency divider which is connected at the output of the amplifier. This

CMOS IC4017 divides the input frequency by 10 so the 40 kHz signal becomes 4 kHz, which is

enough to have an audible range of sound. This 4 kHz signals are then fed to op-amp IC741

(IC2), which is wired as an earphone amplifier.

This device is powered with a 9V DC rechargeable battery which is also attached to a

case together with the circuit board. With this device it can give an enough signal that will enable

the user to avoid head and eye level obstructions.

Due to the unwanted results because we cannot set the detected area the ultrasonic sensor

continuously sends data to the decade counter and op-amp which results for a continuous output

of sound alarm that might irritates the user. So we have decided to make some research to make

this device a more user-friendly. Then we come up to the idea of using microcontroller to make

this a user friendly and more accurate device.


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1.5INNOVATIONS ADDED

The innovation added to this device is the usage of two ultrasonic sensors instead of

using one to help protect the user more. We also make an arduino compatible board instead of

buying a kit which causes for almost Php1000.00+ (the original arduino board) though there are

available compatible boards in the market like the Gizduino which causes Php 600.00+ it is still

not that good for us because we want to make this device affordable so we have decided to make

one compatible board for this project since there are lot of references and sources on the net

showing tutorials on making compatible boards.

We have use an arduino compatible board to minimize the use of other components and

to maintain the minimalistic look of the device so that the device will be small and more

comfortable to wear by the user. Arduino board is use not just to drive with the latest technology

but to explore its ability in this project.

On the first project, which is composed of some capacitors, transistors and integrated

circuit this is eliminated with our second project, so that we could make this device more

minimalist.

With the sensor used, we created this device using Ultrasonic Sensor also known as sonar

instead of concentrating on Infrared LED lights though it is cheaper but we do not want to

sacrifice the accuracy of the distance range. Infrared LED lights has a smaller scale of detectable

distance and not so accurate specially when walking outside with the presence of lights.

The device is composed of two sensors with different alarm signals to help the user easily

determine where the obstacle is. The first sensors alarm is a dc vibrating motor; we got one from

our scrap Nokia 5310 phone. This is attached to the users wrist with the ultrasonic sensor.

The second sensor uses a buzzer as alarm. We have use a buzzer because our major focus

on making this device is to protect head level injuries. And this alarm signal will easily detected

by the user since it has an audible sound output. We have also attached two LED lights just to


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determine if the device really works. The green LED indicates a power on the device and the red

LED lights when an obstruction is detected at head level.

This device is supplied with a 9V rechargeable battery attached to the case together with

the circuit board. With this device we believe that it can help visually impaired people lessen

their worries walking outside and doing their everyday task.


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CHAPTER II

SCHEMATIC DIAGRAMS

FIRST PROJECT

ORIGINAL CIRCUIT

ORIGINAL DEVICE


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INNOVATED DEVICE

Block Diagram

Ultrasonic Sensor (US-100)

Innovated Circuit

40KHz

OSCILLATOR

40KHz

AMPLIFIER

FREQUENCY

DIVIDER

AF

AMPLIFIER

EAR

PHONE

TX

1

RX

1


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SECOND PROJECT

ORIGINAL CIRCUIT

DIY ARDUINO BOARD

- Source: Gizduino facebook page


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ORIGINAL DEVICE

DC Vibrating Motor with Arduino

Original Program Sketch

- Source: M ake Magazine


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INNOVATED CIRCUIT

Arduino Compatible Board


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INNOVATED DEVICE

- Two Ultrasonic Sensor, Vibrating Motor, LED and Buzzer connection with ArduinoCompatible Board


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PROGRAM SKETCH


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2.1 COMPARISON OF ORIGINAL AND INNOVATED DEVICE

On the first project we have done, we change the infrared LED to ultrasonic

sensor to make this more accurate. Infrared LED is cheaper but detects a shortdistance unlike ultrasonic sensor although Infrared is used in obstacle detection it

is not recommended to use as proximity detection with exact range. The ultrasonicsensor (US -100) is temperature compensated therefore it is accurate even the

temperature outside changes.

The alarm signal could be hear through an earphone we didnt use buzzer

with this application because we think that it is more applicable to use outside so

that other people wont be affected with the noise given by the buzzer.

But because of the inconsistencies of this device, we have come up to the

idea that we need to upgrade this device through the use of microcontrollers. Wehave use arduino compatible board with ATMega 328, two ultrasonic sensor, dcvibrating motor and buzzer.

The original device with arduino is just a vibrating motor and the other

diagram shows an ultrasonic sensor interface with arduino. We have used this twoto develop our device.

This resulted to make our device more efficient, accurate and user friendly.

The device gives an alarm to the user once it detects an obstacle with a range of

100cm (1m). The two ultrasonic sensor is connected to the buzzer and vibratingmotor to give an alarm. While the two LED lights mounted at the casing indicatesthat the sensor at the users cup functions green LED light indicates that the sensor

work and the RED indicates that an obstacle of 1m is detected.


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CHAPTER III

DIAGRAM AND COMPONENT LIST

FIRST PROJECT

3.1 PCB LAYOUT

3.2 PCB COMPONENT PLACEMENT GUIDE


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3.3 COMPONENT LIST

3.4 COMPONENT PRICE LIST


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SECOND PROJECT

3.1 PCB LAYOUT

3.2 PCB COMPONENT PLACEMENT GUIDE


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3.3 COMPONENT LIST

3.4 COMPONENT PRICE LIST


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CHAPTER IV

DOCUMENTATIONS

ON OUR FIRST PROJECT


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ON OUR SECOND PROJECT


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FINISH PROJECT WITH CASING


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CHAPTER V

CONCLUSION AND RECOMMENDATIONS

We are thankful that our project was finished after the trial and errors that we have taken.

With this project we learned a lot of things about electronics; applications of decade counter and

op-amps, how does ultrasonic sensor functions, what is atmega328 and arduino. We have learned

also that the C language/programming we have could be applied in a lot of things.

Therefore our group concludes that these two devices could really help visually impaired

individuals to lessen their worries about walking outside and in doing their everyday task. The

second device is minimalistic and functional in all aspects.

This device could still be developed and be more functional. They can still add someadditional features like GPS to locate blind people and a lot more. And if this device be

developed more we could say that this device will really help and make the life of visually

impaired people easier.

Documents

Final Write Up_1