voice assistive smart walking stick for blinds using IR sensor, voice recording module, GPS and GSM Techniques

1. Project Presentation
on
“Voice Assistive Smart Walking Stick for
Blinds using GPS and GSM Techniques”
VTU-Center for Post Graduate Studies, Bengaluru Region Visvesvaraya Institute of
Advanced Technology Muddenahalli, Chickballapur – 562 101
presented by
AMBIKA R
USN: 1VW16LDS01
Under the guidance Of
Dr. SARIKA RAGA
Associate Professor & chairperson
Dept. of DECS
2017-2018

2. CONTENTS
• Abstract
• Introduction
• Objective of the proposed system
• Block Diagram of the proposed system
• Methodology
• Results and discussions
• Advantages and Limitations
• Conclusion and Future scope

3. ABSTRACT
• This project presents a design and implementation of smart walking stick
that helps the blind people to travel individually.
• The proposed hardware system consists of Arduino Nano, IR sensor, voice
playback module, GPS receiver module and the GSM. The Detection of
obstacles is done using an IR sensor.
• The IR sensor detects the presence of an obstacle in front of it and passes
the data to Arduino Nano. The data will be processed and is fed to the voice
playback module which provides voice alert to the blind person through a
speaker in order to avoid the collision between the obstacles.
• The stick is also mounted with the moisture sensor that detects and alerts the
blind if any moisture content is present to avoid slippery paths.
• The GPS receiver has been used for safety purpose to track location of the
user. If the blind people need any help then they can trigger an emergency
button which is mounted on the stick then the GSM will sends the location
information to the predefined contact numbers.
• All effort is being made to make this stick is to be cheaper as well as easy
to use. With all these features the blind people can boost up their navigation
ability and not to depend on anyone while walking in unknown places.

4. INTRODUCTION
• Blindness may be caused due to temporary or permanent injure to any portion of
the eye, the optic nerve, or the area of the brain responsible for vision can lead
to blindness.
• Visually challenged people facing many problems in their everyday life, often
have a difficult time to navigate outside the environment.
• Worldwide, between 300 million and 400 million people are visually challenged
due to various causes . According to world Health Organization (WHO), about
36 million are blind.
• Earlier blind people were totally depended on coached dogs and white canes to
move independently in unknown areas.
• Many electronic devices are came into exist apart from the white cane thus
reduces the problems facing by people who are with disability.
• A simple system has been planned and developed which help the blinds to move
independently.

5. OBJECTIVE OF THE PROJECT
• Object detection: IR sensor which is called as object
detection sensor is used to avoid the collision between the
objects and the blind person, to make the blind person
more convenient to move independently water sensor
which helps in identifying moisture content to avoid
slippery paths.
• Voice feedback upon object detection: To give
notification about the presence of an obstacle, a voice
alert is produced through headphones or speaker by
voice playback module in order to avoid the collision
between the blind person and obstacles.
• Location finding and emergency unit: Emergency
switch has to be implement to send location SMS to the
predefined number using GPS and GSM module in order
to save the blind person from danger.
• The entire system is designed to be small and easy to use
hence it should be cost effective.

6. Block Diagram of the Proposed System

7. System Components
1. Arduino Nano
2. IR Proximity Sensor
3. Moisture sensor
4. APR33a3 voice play back module
5. Speaker
6. GPS module
7. GSM module
8. Emergency switch
9. Liquid Crystal Display

8. METHODOLOGY
Object Detection and voice
alert segment
The system architecture of the object
detection and voice alert segment is shown in
fig below which consist of IR proximity
sensor to detect neighbouring obstacles then
the obtained data is given as input to the
Arduino Nano microcontroller to asses the
situation. The feedback is sent to the user
through voice play back module to alert him
or her from identified obstacles.
 The flow chart of the object detection
and voice alert segment is shown in fig
below The flow starts by powering the
Arduino microcontroller and runs in a
continuous loop.
 sensor sense the near by objects without
stopping until the specified range
reached. If the estimated distance falls
within the ranges, then the user is alerted
by voice notification or else the sensor
will continue to search an object.

9. Location Finding and Emergency Segment
• The GPS and GSM play a main role in the emergency
segment. The use of the GSM module is to allow the
user to send an SMS to the emergency preset contact
number for help.
• The GPS is able to fetch the latitude and longitude of
the location and sends the coordinates through GSM for
tracking the user. The architecture of location finding
and emergency segment is shown in figure.
• In case of any emergency help need by the blind person
then the user can press the emergency button, once it is
triggered the Arduino sends a location coordinates which
are accessed by the GPS to the predefined contact
number.

10. Arduino Nano
• Arduino Nano Board is an open source hardware as well as software hence this is
very similar to the computer.
• All the components used in this project are interfaced with the microcontroller
ATmega328 which processes the signals coming from different components or
sensors.
• Arduino Nano can be programmed with the Arduino software called Arduino IDE.
• The ATmega328 comes pre-burned with a boot loader that allows to upload new
code to it without the use of an external Hardware programmer.
 Small in size
 Operating voltage (logic level):5V
 Input voltage:7-12V
 Digital I/O pins: 14 out
of which 6 provide PWM output
 Analog input pins: 8
 DC current per I/O pin: 40mA
 Flash memory 32KB
 SRAM: 2 KB
 EEPROM: 1 KB
 Clock speed: 16MHZ

11. IR proximity sensor
 5V DC operating voltage.
 IR Transmitter and Receiver
 Range: Up to 0-20cm.
 Adjustable detecting range.
 Built-in Surrounding Light Sensor.
 200mA supply power.
 Sensor as mounting opening.
 Small, Cheap and low power consumption.
 The IR sensor contains a pair of transmitter LED and receiver
photodiode. The transmitter continuously emits infrared
radiations, when the signals hit by an object some of the rays
reflected and is received by the photodiode.

12.  The received continuous signals are fed to the positive input of comparator
op-amp IC LM358 and are compared with the reference voltage at the other
input.
 When the strength of the transmitter led is high, more energy will be
received by the photodiode, the voltage across the photodiode drops, and
the voltage across the positive input gets higher than the negative input of
the comparator, then the output becomes high and led turns ON which
indicates the presence of an object.
 Similarly when there is emission of IR rays towards photodiode then the
output of comparator is LOW and led turns OFF which indicates the
absence of an object.

13. Moisture sensor
 The moisture sensor is a
straightforward moisture discovery
circuit which consists of two probes
those allow the current to pass
through the soil and then it gets the
resistance value to measure the
moisture content.
 Its output turns out to be high when
input is low that is the reason it is
known as inverter IC.
 At the point when there is no
moisture in soil probe 1 of IC7404
turns out to be low a result of this
yield stick 2 goes high.
 At the point when adequate measure
of water is there then it will wind up
damp and stick 1 of IC7404 goes
high which make stick 2 of IC7404
low.

14. APR33a3 voice playback module
 APR33a3 voice record and playback board
is used as a voice guidance system to the
blind person, which is interfaced with
the microcontroller;
 It gives voice alert to the blind person through
speaker or Headphones when an object is
sensed by the IR sensor.
 It has 8 channels each having 1.3 minutes of
recording length.
 The APR33a3 series are the Analog-to-digital converter which means converts
the speech signals picked up by the microphone into a digital signal and passes
the same to the APR33a3 IC where the voice signals will be stored in the non –
volatile flash memory.
 The APR33a3 series are a fully integrated solution offering high performance
and unparalleled integration with analog input, digital processing and analog
output functionality.

15. Single Chip, High Quality Audio/Voice Recording
& Playback Solution.
Operating Voltage Range: 3V ~ 6.5V DC.
680 sec.(11 Minutes at 8 KHz Sampling
rate) Voice Recording Length in APR33A3.
Powerful 16-Bits Digital Audio Processor.
Non-volatile Flash Memory Technology . No
Battery Backup Required
Very Low Standby Current: 1uA . Low Power-
Down Current: 15uA
Supports Power-Down Mode for Power Saving .
Built-in Audio-Recording Microphone Amplifier
High Quality Analog to Digital and PWM module
Resolution up to 16-bits
Up-to 8 voice messages record & playback

16. GPS Module
 The global positioning system is a space-based
navigation system that provides location and
time information in all weather conditions ,
anywhere on or near the Earth where there is an
unobstructed line of sight to four or more GPS
satellites.
 The GPS system contains three sections
1. space segment: satellite constellations consist
of 24 satellites which are setup on six orbital
planes each contains 4 satellites around the
earth.
2. control segment: The control segment
monitors the performance, transmission and
condition of the satellite.
3. user segment: In the user segment the GPS can
contribute services to an infinite number of
users. It allows one-way time of interval
ranging.
 The system uses only two frequencies L1
(1,575.42MHz) and L2(1,227.6MHz).

17. GSM module
 GSM acronym stands for Global System for Mobile
communication which is acts as communication two
persons.
 In this project we are using SIM900 GSM module built
with dual Band GSM/GPRS engine-SIM900A which
works on frequencies of 850/900/1800/1900MHz.
 This module can be connected to the microcontroller
which allows the GSM module to communicate with
the mobile network by sending or receiving messages.
 In this project the GSM is used to send a SMS about
location information to the parents using an extended
AT command set to the contact number which is linked
with GSM system.
 The location message will be sent through the module
by connecting Tx , Rx and GND with the
microcontroller.
 When an emergency switch is pressed by the blind
person the location message will be sent to the
predefined contact number.

18. RESULTS & DISCUSSION
1. Object Detection
Objects may be present on the lower surface in the route
of the blind or high level objects in front of him. A variety
of objects at varying distances and heights are placed,
and later the sensor is linked to oscilloscope to know the
received signal variation. We get result as no signal, If there
is no obstacle on the lower surface or in front of sensor.
The environmental noise show on the oscilloscope as a very
weak signal as shown in above Fig. If an obstacle present in
front of sensor a obtained signal by sensor with amplitude
greater than that received signal by disposed sensor.
2. Voice feedback upon obstacle detection
We also checked the voice notification using the
voice playback warning module and it is able to provide
the correct instruction to the user through speaker and
the obtained data is listed in the Table 1.
(1) No object
(2) object in front of the blind

19. 3. Location finding and Emergency Unit
 The emergency button used in the smart walking stick to
send the location message to the preset contact number.
 To make GSM to be trigger the microcontroller has to detect the interrupt for once.
 Sequences of 20 tests were performed, 60% of all SMS was sent within one minute. 70% of SMS was
sent under 2 minutes and 80% of the messages were sent within 3 minutes. Finally 90% of the messages
were sent within 4 minutes and the remaining are failed to send an SMS after 5 minutes.
Screenshot of SMS Received by predefined number and LCD Display and location access
on Google map

20. complete prototype representation of walking stick

21. ADVANTAGES
• Helps blind to easily walk to destination without collision to the
obstacles.
• Detects obstacles and alerts the blind person through speech
output
• Blind person’s location can be tracked whenever needed which
will ensure additional safety.
• Easy to use and low cost
• Even extendable in future.
• Very low power consumption
LIMITATIONS
• Minimization in cost leads to compensation in performance.
• Detection of exact object cannot be obtained flickered due to
sunlight.
• The GPS may not provide proper location if it is very cloudy

22. CONCLUSION
 The main goal of our research is to provide a smart walking stick
to the blinds to navigate around the environment without any interaction
with sighted people and that should be very cost effective and ease of
use.
 The hardware implemented using Arduino Nano hence the system is
small in size also comfortable to carry along.
 The voice playback module is comfortable to give instructions by using
any language so that the system can be used by worldwide.
 The GPS and GSM modules are successfully operate in sending the
location SMS within 2 minutes hence the work of sending message has
successfully completed.
FUTURE SCOPE
 The system can be modified by adding flame detector sensor to
alert them to escape from the fire accidents.
 The principles of radar can be used to detect the long ranging target
objects. By identifying the color of tablet box a blind person can intake
the tablet for his health issues this can be achieved by implementing the
Color recognition sensor technique so that the medication problem for
visually impaired can be avoid.

24. THANK YOU