2. 2
Table of Contents________________________
Mentor/Associate Verification 3
Design Brief 4
Problem Description and Process 6
Plan of Work Log 8
Research 9
Brainstorms and Ideas 12
Possible Alternate Designs 16
Final Design Description 19
3D Design Drawing/Layers 21
Utilized STEM Concepts 23
Utilized Areas of Technology 24
Reference and Resource Citation 26
Final Design Evaluation 28
3. 3
Mentor and Associates Verification__________
Verifications include the following persons:
Advisor Verification:
Name: Shannon Bunch
Address: 4771 Campus Drive, Irvine CA
Occupation: Science Teacher
Visually Impaired Associate:
*Per request of the associate, we did not include his address.
Name: Hamid Deyhimi
Address: Not Provided
Occupation: Piano Teacher
Mentor Verification:
Name: Mohammed Mohammed
Address: 2 Reunion Street, Irvine CA
Occupation: Self Employed
4. 4
Design Brief_____________________________
Context:
The engineering design competition is structured around aiding disabled people so that they
may become more independent. One such group that we decided to focus on is the blind and
visually impaired. What we want out of this project is to be able to help them navigate with
more ease, and for those affected by our work to feel more independent.
Task:
We will divide our team into two departments so to say; a hardware department that will be
responsible for engineering the design’s hardware and physical aspects and a software
department that will be responsible for all the coding and software needed for our final product
to be successful. After deciding on the design, the hardware department’s task will be to
research what parts are necessary in order for the prototype to work as intended. After the
hardware department finishes wiring everything together, the apparatus will be handed over to
the software department to decide how to make optimal use of the hardware to fit the
personal needs of a visually impaired person.
Restrictions:
The restrictions will be listed below, with a short explication of each one as follows:
Building a “Universal” yet Specified Model: As a model designated to aid impaired
people, the model must be flexible enough in design to accommodate people of varying
body type and forms, but specific enough to help the person whom we are personally
helping.
Cost: We want to be able to create the most efficient model for the most favorable price.
This includes keeping in mind that anyone who needs a product such as this will be able
to obtain it.
Time: With only a certain amount of time to finish a working prototype, time must be
used wisely and efficiently so as to put out the best final model and solution to the
design challenge.
Investigations:
The research involved will include the needs and preferences of the visually impaired, the
different methods that could be used for navigational aid, the use of any and all types of
electronics that can be used in the model-especially of microcontrollers, which are of particular
interest and use for this project-, the programs of code that can be used to control the
hardware elements (electronics), and how to work with electronics for personalized use.
5. 5
Design Brief (cont.)_______________________
Development:
In order to fully develop our project, we would like to make full use of any resources that we
have, including equipment that we already have so that we can cut costs down, enlisting the
help of outside sources, and testing the prototype with someone that the product was designed
for. We will hold six entire group meetings as well to further our progress, planning and
designating new tasks at each meeting. Each member is expected to report progress and
provide ideas.
Production:
By the end of this project, we expect the end result to be a prototype that is able to
navigationally assist a blind or visually impaired person by informing them of incoming
obstacles or directing them toward more favorable paths. We expect that the result will be
both low cost and effective.
Evaluation:
Our final product will be an apparatus that will attain distance information and send it to a
given synchronized smartphone that will, based on the distance data, deliver one of several
messages hinting to the approximate proximity of an obstacle. The microprocessor will mediate
the transfer of distance data between the ultrasonic sensor and the smartphone. The attached
Bluetooth chip will then facilitate the transfer of information from the board to the smartphone
wirelessly. The smartphone application will from there compare the obtained distance
information using a number of if statements and appropriately alert the user through a
Bluetooth headset. We will first split the team into two factions, one to handles hardware, and
the other to implement the software; each faction will conduct the needed research before
proceeding. The final product must be light, user friendly, and as economic as possible.
6. 6
Problem Description and Process____________
People that are visually impaired more often than not require the use of canes in order move
around, whether it be inside their own homes, or outside. This leads to a dependence on
objects, in the case of the cane, that are outmoded and cannot always be relied on to relate
accurate interpretations of the world that allow free movement without hesitation. What we
seek to accomplish is the creation of a model that can be used in conjunction with the cane,
and even without the cane that allows for peace of mind for the person using the model to be
able to move around knowing that the walking path ahead is safe to follow.
The steps that we will be taking to solve the problem at hand are the original steps to solving
any problem, and will progress the entire process of designing and executing the project to
completion.
1. The first thing that we worked through was defining the problem that we wanted to address.
This first step was the problem identification step. Knowing our own capabilities and resources,
we determined that we would be able to address the problems that face the visually impaired
most effectively. These capabilities include the use of hardware such as microcontrollers and
the combined wiring and the use of computer programs. The resources that we had were the
hardware components as well as project encasings and tools that would easily allow us to fit
the person using the model’s form. Another reason we chose to aid the visually impaired is due
to the fact that we are able to create a non-medically invasive solution that can greatly improve
the living conditions of someone visually impaired.
2. The second problem solving step that we will now address is the investigation of solution
types, and the ability to apply certain components that we are able to use to help improve the
living conditions of the visually impaired. This investigation includes research on the topic of
how visually impaired individuals get around and the different methods that can be used to
navigationally aid these individuals. Navigational aid is specifically referenced here as helping
visually impaired individuals to walk more freely in open or unfamiliar spaces without hesitation.
In order to achieve this, we will research ideas that we currently have regarding the process of
navigation including distance detection. From there, the investigation will become more narrow
in scope, as we hope to be able to use electrical components such as the aforementioned
microcontrollers and programs of code to work within the model, making it small, easy to use,
and user friendly.
7. 7
Problem Description and Process_(cont.)_____
3. The third and next step we plan to take is to brainstorm how the current ideas we have, such
as the use of microcontrollers, wiring, programming, and navigational distance detection will be
able to be applied into a working model. In this process, we plan to come up with several
solutions that allow for flexibility between specific users of the model, so that anyone will be
able to use it freely. In addition to simply brainstorming, we will be checking resources on the
navigational complaints of blind people(getting from place to place) to stimulate the process.
The brainstorming documentation will be kept as notes and analyses of the ideas from
meetings that we will be held.
4. Having already been divided into two “teams” within the group, the next step in the process
is to begin building the model that we have decided upon after brainstorming all viable options.
Once the most optimal solution has been agreed upon, the hardware team will be allowed to
work with project encasings and wires that will be used, and the software team will program
the specific code that encompasses the solution’s method of aiding navigation. This step will
ultimately be the building and prototype creation step.
5. The final step includes troubleshooting, fixing any hardware issues, and tailoring the model
to fit the personal needs of someone who is visually impaired. The production of a fully
functional prototype without any bugs is key to the efficiency of any design that is created, so
as to minimize any restriction of time and cost. Also included in this step will be the handing
over of the prototype model to a visually impaired person, who will determine how efficient the
prototype is.
8. 8
Plan of Work Log_________________________
Date Task Time
Involved
Team member
responsible
Comments
1.
December
14th, 2013
-Brainstorm ideasand
researchtopics that
pertainto possible
models
-Start design notebook
0.5 hr/day
until next
meeting
All members are
responsible for this
task
-Suggested that microcontrollers be
researched, and infraredandultrasonic
sensing be lookedinto
-Notebookprogress shouldbe updatedevery
week withinformation
2.
December
28th, 2013
-Suggest concrete
models and decide on
one final solution.
-Begingathering
materialsfor the build
0.5 hr/day
during the
weekend
until next
meeting
All members are
responsible for this
task
-Decisionhasbeen made after meetingto
work on a “waistband” model, using the
Arduino microcontroller
-Progress made shouldbe reportedat next
meeting
3. January
11th, 2014
-Beginbuilding the final
solution prototype
-Start programming
microcontroller
0.5-1
hr/day
during
weekends
until
finished
Hardware:
Taymour, Arian, Ali
Software:
Vijay, Tahmid
Notebook + Display:
All members
-Anyprogress made shouldbe reportedat the
next meeting
-The hardware shouldinclude wiring the
controllers and working withthe encasing
(done within1 month)
-Software shouldbe done withinthe same
month
4. January
18th, 2014
-Continue working on
the model
-Start the displayfor
the project
0.5-1
hr/day
during
weekends
until
finished
All members are
responsible for this
task
-All progress made with the notebookand
displayshouldbe reportedat meetings.
-After meeting, hardware andsoftware design
are well underway
5. January
25th, 2014
-Software crewfinish
codingand testing and
hand over board to
hardware crew to finish
encasing it
-Continue displayand
design notebook
1 hr/day
during
weekends
to finish
original
prototype
Software finish:
Vijay, Tahmid
Hardware finish:
Arian, Taymour, Ali
-The product shouldnowbe finishedwithin
about a week, readyto be tested.
-Testing willoccur byhandoffto a blind
associate whohasagreedto pilot the model.
-Displayandnotebook shouldbe finished
soon after prototype
6. February
15th, 2014
-Hardware crewfinish
encasing board
and have the product
readyto test as a whole
-Test product
-Finishdisplayand
design notebook
2+
hours/day
anyday
possible
until
finished
All members are
responsible for this
task, especially
finishingthe display
and notebook
-Get direct feedback from a blind associate
that allows for troubleshooting
-Add finishingtouches to boththe displayand
the design notebook
-Tie up anyloose ends withprototype.
Advisor Signature ________________________
9. 9
Research______________________________
Early in the development phase, we researched the possible disabilities we could address,
taking into account our available resources. We found that we could most effectively help the
visually impaired. There are two distinctions of blind people; there are fully blind people, who
cannot see at all, and legally blind people, people whose vision is poor enough for them to need
help. As such, we reasoned that we could build an apparatus that could help both. Through our
research we found a number of methods with which the blind could get around. This way, we
would know what problems exist that can be addressed by our product and how we could
make a product such that these problems are at least made more subtle. The said methods
include the use of canes, or trained guide dogs or a combination of both. Blind people undergo
a sort of training, labeled Orientation and Mobility Training (O&M), in which they learn to
navigate through their environment using long canes. While canes are relatively economic, they
heavily task the user, since the user is still responsible for navigating on his or her own. On the
other hand, guide dogs can effectively help the blind navigate but are costly to buy and
maintain. Inspired by the disadvantages of the methods of travel we researched, we set out to
create an apparatus that is both economic, fairly easy to maintain and can facilitate blind
navigation all the same.
To determine the hardware that we wanted to use in the model, we consulted several different
information sources that went over materials that could possibly be used, such as the
microcontroller, a sensing mechanism, and energy or power.
Microcontrollers are compact micro-computing system that have been designed for
recreational and or serous uses in industries focusing on cost and space effective technologies.
Some microcontrollers we are looking at include the Arduino Uno, the Raspberry Pi, and the
RFduino. Starting with the Arduino, it is a small microcontroller chip that utilizes between 6 and
20 volts of electricity to run, has a processing speed of 16 MHz, 2 Kb(Kilobytes) of SRAM, 32 Kb
of flash memory, 6 analog input pins, and 14 digital input/output pins. These specifications
allow for the versatile use of a microcontroller such as the Arduino, because of its compact size
and processing capabilities. The Raspberry Pi, another type of micro-computing device, is more
of a computer than the Arduino, though this comes with restrictions. The Pi cannot sustain high
voltage, and needs the assistance of resistors placed in series around it and any attachments so
that the board does not short-circuit. Other than that, the board has a 700 Mhz processor on
chip and contains roughly 256 Mb of RAM. With these processing speeds, the microcontroller is
faster than the Arduino, but this is without taking into factor the partitions of computations and
processing speed that are used for computer-like processes (such as being autonomous,
without the need of an external source of power as an aid). This results in a decrease in speed
used specifically for project related functions. This however, still outmatches the speeds of the
10. 10
Research(Cont.)__________________________
Arduino. The sizes of the two microcontrollers vary in that the Arduino is smaller (about 2.1 mm
X 2.7 mm with a negligible depth), and the Pi larger (85.8 mm X 56 mm X 21 mm). The RFduino
microcontroller is in effect much smaller than either of these, and has processing powers of
about 2.4 MHz, and a size of roughly (15 mm X 15 mm with a negligible depth). The RFduino
requires about 3.6 volts to run, a smaller amount than that of the Arduino.
The sensors that we are looking into include the ultrasonic and the infrared sensors. Ultrasonic
sensors use high frequency ultrasonic waves propagated by a crystal to detect distances of
objects. This would be analogous to sonar. The high frequency sound burst impacts an object
directly ahead, and returns at the same angle to the sensor, where an algorithm determines the
distance from that object based on the time it took to reach the sensor again and the speed of
the sound wave, which is general 343 m/s(meters per second). The ultrasonic sensors that we
plan to use are sensitive to detecting distances of up to 450 cm, or about 17 feet. Infrared
sensors work off of the same principle that the ultrasonic sensors do, but use light sensing, a
much faster and more accurate method of sensing. This sensing involved the reverberations of
a light wave off an obstacle coming back, essentially using the same algorithm, but with the
constant speed as the speed of light. The range of these sensors is up to about 150 cm, or
about 5 feet. The decrease in range from the ultrasonic to the infrared sensors is due to the
cost of infrared sensing, which is considerably higher than ultrasonic, which only goes for an
average price of about 4 or 5 U.S.D, while the price of ultrasonic sensors of the mentioned
range is roughly 18 U.S.D.
The energy that will be predominantly used in this project will be battery power. AAA batteries
provide the same voltage as AA batteries, yet do not hold as much energy as the AA batteries
do. This however is made up by using more of these batteries in series. Because the AAA
batteries are lighter, they are more space and weight efficient.
With regard to hardware, our research now was concerned with analyzing the specifications of
the microprocessor at hand (the Arduino specifically) and how we would interlink all the
separate components. The three people responsible for hardware first researched the
potentials of the Arduino, the central processor that mediates the transfer of information from
the attached ultrasonic sensors to the smartphone that synchronizes with it. Specifically we
looked at what the components of the Arduino we would utilize. We researched how GPIO
(General Purpose Input Output) pins work to get input and send output, how ultrasonic sensors
use ultrasonic waves to calculate its proximity to a given object, and what specifications of the
11. 11
Research(Cont.)__________________________
Arduino we needed to heed while making the apparatus, including its weight, dimensions, and
what voltage it requires to properly function.
After researching and planning out the inner workings of the device, the hardware department
looked into how we could engineer a case to contain the finished device; this research included
what the optimal angle of the sensor would be once the device is integrated into its case,
where the device should be strapped onto the body, and how to maximize comfort. This was
significant because we had to take into account the fact that ultrasound is just another type of
wave; it can be reflected and dispersed by nature. In essence, our goal was to orient the sensor
such that it would be able to receive resonant ultrasound from an object directly in front of it.
We had to specify what type of gear it would be as well. We first thought about making our
product headwear, but this was quickly eliminated, as the sensor may be too high to detect
obstacles and a person’s head is not static. If we were to make our device headwear, it would
be subject to the angles and movement of the said head, which would disturb the sensor’s
operation. We compromised to make it a sort of strap-on apparatus for the waist after
The two people responsible for software development were responsible for researching the
algorithm needed to interpret the ultrasonic sensor data, understanding the underlying logic
behind this algorithm, and discovering how to implement code that will successfully allow the
Arduino to transfer sensor data to the smartphone. The Arduino has its own programming
language; this was the subject of our research early in the software development phase. We
researched how we could program the board such that it triggers the sensor to fire ultrasounds
in set regular intervals; the sensor has a cycle period of about 25 milliseconds so the Arduino
was programmed to send trigger signals accordingly. After the sensor gets the time data, we
needed a way to convert this data to distance data that the smartphone can use; this is where
our research of the ultrasonic distance algorithm came into play. What we got from the sensor
was the amount of time the ultrasound took to resonate back to the sensor. We used the
distance, speed, time formula to find distance, as we knew the speed of sound and the time.
After coding the board to get and send distance data, we looked into android application
development since we would be utilizing a smartphone application that would work in concert
with a bluetooth headset to communicate distances with the blind user. Specifically, we looked
into java code, the aspects of the android SDK we would have to make use of, and how our
application could communicate with a synchronized smartphone. The android application is
programmed to receive the data in set aforesaid intervals. For this we had to look into the
Andriod API; specifically we looked into the methods and operations relating to Bluetooth and
data transfer that were available in the Android SDK (Self Development Kit).
12. 12
Brainstorms and Ideas___________________
All brainstorming will be kept as a series of journal-type entries in this section. All team
members’ ideas are kept in this section. New ideas are added during team meetings.
December 14th, 2013:
-In order to help the visually impaired, something that aids navigation will be best. This way, the
impaired person is able to feel more independent, more confident, and less hesitant about
moving around on his or her own.
-A device that could help the visually impaired navigate could work like a GPS device, alerting
them as to where they are or to where they are going. (This might be hard to accomplish,
seeing as it requires GPS tracking and that we probably don’t have access to that.)
-A device that is able to detect distances and can relate them to the visually impaired user. (This
sounds promising, but we will have to work out how the device will do this.)
-A device that is able to use cameras to recognize locations, and direct the user around known
spaces. This would include using the device to memorize spaces. (In theory the idea is good, we
will have to work out how we would go about it though, and what kind of work would be put
into memorizing places. New places may be hard to navigate though.)
-With any device that is created the position of the device will have to be noted, and the device
will have to be light, since we are sure it will be a portable and easy to use model.
-The device must be cheap enough for a user of any household to be able to easily be able to
purchase it, and therefore must utilize sturdy but low cost electrical components that allows for
a simple user-interface.
-As for where the device can be help, some ideas include: a wearable item on the head, waist,
arm, around the neck, or held in the pocket.
December 28th, 2013:
-After debate, the GPS idea is being eliminated as it is far too complicated a solution for the
resources, and not beneficial to the user due to a number of discussed reasons at the meeting.
These reasons include a limited access to GPS tracking ability, and the inaccuracy of the
available tracking options available to us. If we can’t accurately track movement, especially with
the lag time between the GPS position tracker and the receiver, then we cannot give correct
minute by minute instructions that would be necessary.
-As a team, we have decided that we will move forward with brainstorming ideas on the
distance detection idea, and that the camera idea would be too slow to catch on for someone
who needs to move about.
13. 13
Brainstorms and Ideas (Cont.)_____________
-Some ideas regarding the distance detection idea include the use of some electrical
components. We have heard of sensing such as sonar and light sensing that determine
distances. These ideas will be assigned to be researched more fully.
-The electrical components that help use the distance detection model have to include
something like a computer, so that the information can be sent along after being processed.
Sensing can only send the information, not process it.
-Looking into microcontrollers such as the raspberry pi and the Arduino will be assigned, the
Arduino is a microcontroller that can process data, and the pi is a small computer.
-The cost must be taken into account, so far all ideas that have come forth are economically
efficient as far as we are concerned, and the size will be compact as well.
-The device design as far as we have come up with could include glasses that can be worn on
the head, a necklace that contains the components, or a belt that can be strapped across the
waist. The benefits of each model will be taken into account.
January 11th, 2014:
-The electrical components that were addressed last meeting that included the Arduino,
raspberry pi, and sensing apparatus have been researched. The Arduino seems to be the better
model, as it needs no voltage regulation, and an application can easily be made to
accommodate communication.
-The different sensing techniques include infrared sensing, a type of light sensing, and
ultrasonic sensing, a type of sound sensing, are now being considered.
-The sensors can be placed ahead of the model as a whole, facing away from the user so that
they can detect objects ahead. This eliminates the pocket idea for the model.
-Infrared sensing can be used for shorter distances, and as we now think is faster and more
accurate than the ultrasonic sensing. Ultrasonic sensing can be used for greater distances, and
is less costly than the infrared sensing. These two method can be further researched.
-As for the placing of the device, the designs stand as glasses, a necklace, or a belt. Some ideas
that are conflicting with the glasses include that they may be too high to detect much for
certain users. The necklace idea may hold the same height problem. The belt idea however
seems low enough for most users to be able to detect distances without issue.
-For the electrical components, power must be supplied. Ideas regarding that include battery
packs. The number of batteries we estimate at this time is 3-4 AA batteries.
-With the belt model in place, ideas of how to hold the entire apparatus include a buckle-on
belt strap, and the model will be light enough to stay on.
14. 14
Brainstorms and Ideas (Cont.)
-The encasing of the model can include a plastic encasing that is pre-made and then shaped to
fit our needs for the model, or can be a 3D printed model made to our specifications.
-The coding for the Arduino using either type of sensor can detect in several different fashions.
These include simply sensing objects a certain distance away or sensing a change in distance
between the user and an object ahead.
January 18th, 2014:
-We have established that the sensing mechanism should be ultrasonic. Ultrasonic sensing is in
fact not slower than infrared, contrary to previous ideas, and is still cheaper.
-The ultrasonic sensor can be utilized in a number of ways that were considered last meeting.
These include using it to sense concrete distances or distance changes. The distance changes
ideas is better, due to the fact that objects that remain at a constant but close distance will not
“spam” the user with unnecessary messages.
-The batteries that were mentioned last meeting can be included in a compact battery pack,
which makes them more safely stored, and more compact.
-The type of batteries can be either AA or AAA, depending on the voltage necessity of the
microprocessor(Arduino). The amount remains at either 3 or 4 batteries for now until further
changes are made.
-A small encasing was found, and due to the cost of 3D printed, it was decided against. To get
the encasing onto the belt, the belt may have to be run through the back, or something
attached to the backside of the encasing so that the belt stays on.
January 25th, 2014:
-A battery pack has been found to house the batteries. 4 AAA batteries are now the standard
source of energy, and will be placed into the encasing.
-The space within the encasing is limited, and packing all components will require extra thought.
The items that must fit within the casing are the Arduino, the battery pack, the sensor, and a
switch to regulate the on/off capabilities of the model and to preserve battery.
-Since the items will not all fit on the bottom, we are suggesting that either the Arduino or the
battery pack is raised, or both are raised above the side of the box encasing. This will also allow
for easier exchange of used batteries.
-As for the actual putting together of the model, we have suggested several ideas, which
include putting the switch on the side, and the sensor out in the front, able to be moved slightly
around its opening.
15. 15
Brainstorms and Ideas (Cont.)
-As for the coding that has occurred up until this meeting, the work was done in creating an
application on the android interface that allows for easy communication with the device.
-The idea for the encoding was suggested as sensitive to changes in distance, which is
calculated using an algorithm that we used from the ultrasonic distance calculations.
February 15th, 2014:
-Any new ideas occurring at this meeting will be thought of as finishing touches to the entire
process as the model is finished.
-Handing the model off to the associate will allows us to troubleshoot for any flaws in the
design, and to accommodate requests as necessary.
-It is suggested that everyone looks over the areas that they handled and fixes any issues after
the device is back within our possession.
16. 16
Possible Alternate Designs_________________
Arduino Model:
The model here specifically utilizes the Arduino microcontroller, which is used to process
incoming information in the digital form. The model is part of the more general “waistband”
model that attaches to the waist via a belt. The processor and other electronic components
would be held within an encasing.
Advantages:
. The Arduino does not need a high voltage, and is rather voltage tolerant, allowing it to
use the ultrasonic sensor safely and efficiently.
. The low height of the waistband model used allows for detection of lower objects,
allowing the user to avoid object having been placed more near the ground.
. The processing power combined with the use of a Bluetooth shield allows the Arduino
to easily communicate with the user.
Disadvantages:
. The size of the Arduino microcontroller and microprocessor is not fully space efficient,
and although small still takes up space around the user’s waist.
. The voltage necessity of the Arduino model requires a greater number of batteries to
power the model, resulting in a slightly larger weight for the overall model.
Glasses (General) Model:
One alternative design was to attach the Arduino directly to a pair of glasses prescribed for the
user. This design would have included the sensors on the right handle of the glasses. In addition,
it would have included the batteries and the computer chip on the left handle of the glasses.
The glasses could have been sunglasses or clear glasses, depending on the user’s preference.
Advantages:
. The design of the glasses makes them more wearable, and results in an overall easier
user experience with this model.
. The user will not have to refrain from wearing certain types of clothes that may
obstruct some of the other models. The heights of the model on the user allows for this.
. The distance of the model from the ears results in a faster and more time efficient
model, giving alerts and updating quicker.
Disadvantages:
. The glasses themselves, due to the addition of electronic components, may be too
heavy for the user to wear on the head.
. The size and weight of the model could result in an uncomfortable experience for the
user of the glasses model.
17. 17
Possible Alternate Designs_(cont.)___________
. Fitting the electronic components on the model would may difficult, and the risk of
malfunctions could result in injury to the user, which is not permissible.
. The sensors would be subject to the person’s head movements. This could disrupt the
sensor’s readings by frequently altering its angle, and not allowing the device to pick up
the correct signal.
. The user may be too tall, leading to no sensing at the lower levels, where most of the
obstacles may occur to begin with.
Raspberry Pi Model
This alternative model involves the Raspberry Pi computer chip instead of an Arduino chip. This
design would not have affected the hardware of the device but it would have affected the
software and the coding procedure. This model is also part of the “waistband” model
mentioned in the Arduino section, with its electronic components placed in the same fashion.
Advantages:
. The device would be phone application independent due to the Raspberry Pi’s ability
to deliver sound via an audio port, which the Arduino lacks
. The device would be cheaper due to the fact that it doesn't need an independent
Bluetooth chip.
Disadvantages:
. The Raspberry Pi is of larger size than the Arduino microcontroller is, and will therefore
cause the product to be slightly larger and heavier.
. It cannot be updated over time as more issues are resolved unless the creator has
access to the device. This limited access to the device is a reason for its disuse in the
project.
. Unlike the Arduino, the Raspberry Pi can be fried if too much voltage is applied through
its power port. Resistors would be necessary to prevent this and the circuitry will
become more complex than need be, and adding to the overall cost of the model as well.
. The Raspberry Pi also has less memory(RAM), which limits the number of operations
possible at one time and the speed with which the Raspberry Pi can process.
RFduino
This is a smaller alternative that has the microprocessor and bluetooth chip built into it. The
model works off of the smaller RFduino chip, that has less processing capability but allows for
more compact storage. This model is again part of the “waistband” models that includes the RPi
and Arduino models.
18. 18
Possible Alternate Designs_(cont.)___________
Advantages:
. The RFduino is very compact and much smaller than the Arduino allowing for a more
efficient model in terms of space taken up. The model would in this case also be much
less intrusive.
. The RFduino is very light and it doesn’t also need as much power as the Arduino does,
making the overall device lighter, since the bulk of the weight comes from the
microprocessor board. A lower power need means more efficient energy usage.
Disadvantages:
. The model would need an accommodating case that would require extra time to be
spent in creating. The case would be less resourceful and harder to manage, not as
reliable as the current case.
. Less voltage necessity also means that the RFduino can short circuit much more easily,
being that it can only take up to certain voltages, and that it may not be able to sustain
the ultrasonic sensor on such a low voltage per unit time.
*The illustrations for each of these alternative models will not be numbered, but will be
included under the heading of pgs. 16-18 of the notebook.
19. 19
Final Design Description___________________
Our Arduino based model utilizes an ultrasonic sensor to input distance information, a
Bluetooth chip to communicate with a given smartphone, and a battery pack to provide energy
to power the machine.
Sensor: The ultrasonic sensor has a range of operation between 2 and 500 centimeters and 4
pins; VCC, Ground, Echo and Trigger. The VCC and Ground pins are used to complete the circuit
the sensor forms with the microprocessor. The Trigger pin receives input from the board itself
via a GPIO output pin and, upon receiving a signal, will trigger the sensor to send out a blast of
ultrasound. The sensor has a cycle period of about 50 milliseconds so the Arduino is
programmed to trigger the sensor accordingly. Once the ultrasound resonates and returns to
the source, the sensor uses its Echo pin to output the time data to the Arduino via a GPIO input
pin.
Software: The Arduino is programmed to take the data it gets from the GPIO input pin and
convert it to a distance by using the ultrasonic distance equation. After calculating the distance,
the Arduino sends the data to the smartphone via its Bluetooth chip. The smartphone’s android
app will then take the data and conduct several checks. The code involves a number of if
statements that check if the distance is in a certain range.
Hardware: The hardware included in the final design includes the aforementioned sensor, the
Arduino, a voltage switch, a battery pack, and a Bluetooth chip. The Arduino itself is main
processing unit as has been mentioned in this and above sections. It will take in the information
and process it, sending it onto the phone, which interprets the digital message. The voltage that
the Arduino handles is between 6 and 20 volts. This voltage is then supplied to the
microcontroller itself and the ultrasonic sensor, which takes 5 volts by the battery pack that we
used, which takes 4 AAA batteries (1.5 volts each) in series and supplies 6 volts of electricity to
both modules. This meets the voltage necessities of both. To control the flow of voltage that
would allow us to toggle between on and off states of the model, we included a switch that is
attached to both the Arduino microcontroller and the battery pack. This switch controls the
flow of voltage from the battery pack to the Arduino by attaching to the USB and ground slots
on the Arduino, and to the battery pack directly. The Bluetooth chip simply allows for
communication with the phone and other Bluetooth capable devices.
To create to final model, we carried out the following procedure:
20. 20
Final Design Description(Cont.)_____________
Steps of Operation:
-First, we cut a hole in the side of the encasing for the switch that we used, diagrammed in the
design drawing section. The switch was then slid into the hole, and held firmly by the encasing.
-After taking care of the switch, the sensor was handled. Two holes were bore into the front
side of the encasing to allow the sensor to protrude out, and an aluminum holder was
fashioned on the inside of the encasing to hold it in position with the holes.
-So that there is no interference with the sensor, a thin aluminum plate was fashioned to raise
the rest of the components above the sensor. The Arduino is securely bolted to this aluminum
plate with screws and rubber washer. The washers provide electrical insulation between the
metal bottom of the Arduino microcontroller and the aluminum in case of a short-circuit.
-After bolting the Arduino down, the wires were hooked up with professional wire fasteners so
that they would be more manageable, be more space efficient, and would protect against any
short-circuits(there is repetition here to emphasize the importance of user safety). These
fasteners were clamped with a tool and their ends went toward making the switch more safe as
well.
-The battery pack was left at the very top of the design for easier access and changes to dead
batteries that need to be made.
-Finally, the encasing top was closed with screws so that everything fits securely in, and the
model is complete.
23. 23
Utilized STEM Concepts___________________
We namely utilized the concept of determining the distance between the source and a given
object using ultrasonic waves. Ultrasonic waves are sound waves that exceed the maximum
frequency humans can detect (20 kHz) by at least 1980 kHz and can travel through and medium
that is not a vacuum, including air and water. When these sound waves encounter a solid object,
they resonate. At some point this resonance will return to the source of the ultrasound
assuming the ultrasound is not deflected elsewhere first due to angle. This concept is utilized by
an ultrasonic sensor to detect distances. The sound will travel a certain distance d, which
represents the distance between the source and the object. Upon encountering the object, it
will travel a distance d back to the source. In essence, the sound waves will have traveled a
distance of 2d before returning to the source. The sensor records the time t required for
resonance to return to the source. We know that the speed of sound s is approximately 343
meters per second. Using this information and the basic equation relating distance, speed and
time, we can determine the distance d by taking the product of t and s and dividing it by 2.
A technological aspect of the project includes
the Arduino, a small microcontroller board that
we used as an electrical component to
calculate and process the distance information,
then communicate with an open source
application created for the Arduino to relay
information to the user. An electrical signal
sent down the ultrasonic sensor is converted
into a voltage across the Arduino, which is sent
through the microprocessor on board and then
sends another electrical signal via a bluetooth
adapter on the Arduino to the application,
which warns the user of an obstacle ahead.
24. 24
Utilized Areas of Technology_______________
Information and Communication:
Information and communication in today’s day and age is an integral part of society. With the
visually impaired having little to no access to visual information and communication systems
used by many streets, work areas, and even homes, it is hard for them to be able to function as
effectively as other people.
Some of the technology and related ideas that were utilized from this section are bluetooth
communication, cellular communication, distance information, obstacle information, and
navigational information. Bluetooth communication was used as a part of the electronic
components in the model that we chose to create. This model used a bluetooth “shield” for the
Arduino microcontroller that would allow for easy communication between the model and a
cellular device. Again, the bluetooth communication can be seen if the user chooses to have the
phone communicate with a specifically designed bluetooth-receiving headset. This cascade of
communication coming from the model to the user is an integral part of how the project seeks
to help the user, and the visually impaired community in general. The communication that is
directly between the cellular device or phone and the user is an example of the cellular
communication that we used. The information side of the model focuses on providing the
visually impaired user knowledge about the pathway they choose to take, allowing them to
make navigational decisions with ease. The information previously mentioned about distance is
the result of the sensor passing on information, just as the human eye would, to the user about
the length between him or her and an object directly ahead. This also applies to obstacle
information, or information about a course which a person desires to follow. The information
here and with the distance is crucial in understanding how to navigate around any area, and
allows the visually impaired user more free access to areas where he or she may not have been
previously comfortable. The combination of these two information systems is the navigational
information aspect, which integrates all communication and information scenarios into one
discrete unit, allowing the user to easily navigate. With the summation of all the information,
and the correct communication systems in place, our project has been designed to ultimately
lead to this, the provision of navigational knowledge of the world that updates in real time in
order to more easily help the user move about.
Transportation:
Transportation has become engraved in society today and has connected people all over the
world. Unfortunately the visually impaired have difficulties using these transportation systems
because these transportation systems, such as cars and airplanes mainly utilize visual cues to
communicate with the passengers. The device that we have created helps the visually impaired
use transportation systems with more ease.
Using the ultrasonic sensor we have made it easier for the visually impaired to get in and out of
these transportation systems by avoiding collisions. The sensor itself provides the information
regarding distances, providing the user with a vision-like depth perception utilized by the eyes.
Since transportation involves movement, and transportation with ease involves a fluid
25. 25
Utilized Areas of Technology(Cont.)__________
movement that we are defining as obstruction free movement, the visually impaired are not
able most times to transport with such ease. The Arduino works as a sort of transportation
brain that determines whether the user is on what we call a fluid path of movement, leading to
fluid transportation.
In its entirety, the model has been designed for this specific reason transportation, and we
want to call to attention that all electronic components used were to maximize the
transportation abilities of a visually impaired user. The ultrasonic sensor was chosen for its high
distance update rate and its long field of detection. The Arduino was chosen for the processing
power that it possesses and its uses in such things as autonomous devices. These technologies
culminate to our navigational aid system, that was specifically designed for, and is to be used
for, transportation.
Energy and Power:
As an indirect concept in this project, energy is still very important considering the electronic
components that comprise the model we have created. The energy we used is in the form of
batteries, 4 AAA batteries that, in series, provide a total voltage of about 6 volts to the entire
system. The system the feeds off of the voltage, powering both the Arduino microcontroller
and the ultrasonic sensor.
Another key aspect of the energy area of technology here is not just the usage of batteries to
supply a voltage to electronic components within the system itself, but regulation of that
electricity flow. The flow is regulated at the switch, where the circuit from the batteries to
power the Arduino and ultrasonic sensor(which feeds off of the Arduino’s voltage) is either cut
off or continued, allowed the free flow of electricity throughout the system. This is important to
the project as a whole, because it allows to the user freedom to turn the model on and off
whenever he or she no longer needs it, or when he or she no longer wants notifications from
the model. This puts more power into the hand of the user, which has been another key aspect
of what this project has been detailed to do.
26. 26
Reference and Resource Citations___________
"Arduino - FAQ." Arduino. 04 Jan. 2014. <http://Arduino.cc/en/Main/FAQ#.Uwqt3PRdVs8>.
"Arduino - Ping Ultrasonic Range Finder." Arduino - Ping Ultrasonic Range Finder. 04 Jan.
2014.<http://Arduino.cc/en/Tutorial/Ping?from=Tutorial.UltrasoundSensor#.UwlOLPmI
Cm4>.
"Arduino - Products." Arduino. 04 Jan. 2014.
<http://Arduino.cc/en/Main/Products#.UwqtwfRdVs8>.
"Blindness Statistics." NFB. 26 Dec. 2014.
<https://nfb.org/blindness-statistics>.
"Bluetooth API." Android Developers. 11 Jan. 2014.
<https://developer.android.com/guide/topics/connectivity/bluetooth.html>.
"Connecting Devices Wirelessly." Android Developers. 11 Jan. 2014.
<https://developer.android.com/training/connect-devices-wirelessly/index.html>.
"FAQs | Raspberry Pi." Raspberry Pi. 10 Jan. 2014. <http://www.raspberrypi.org/faqs>.
Hawkins, Matt. "Ultrasonic Distance Measurement Using Python." Raspberry Pi Spy. 11 Jan.
2014 <http://www.raspberrypi-spy.co.uk/?s=Ultrasonic>.
Hub, Andreas, TimHartter, and Thomas Ertl. "Interactive Tracking of Movable Objects for the
Blind on the Basis of Environment Models and Perception-Oriented Object Recognition
Methods." ACM. 12 Jan. 2014. <http://dl.acm.org/citation.cfm?id=1169007&dl=acm&
coll=>.
“Microsoft Kinect Teardown." IFixit. 25 Dec. 2014.
<http://www.ifixit.com/Teardown/Microsoft%2BKinect%2BTeardown/4066>.
"Python/C API Reference Manual." Python.org. 05 Jan. 2014 <http://docs.python.org/2/c-api/>.
"Raspberry Pi." Xively. 10 Jan. 2014 <https://xively.com/dev/tutorials/pi/>.
"RPi Hardware." ELinux.org. 10 Jan. 2014 <http://elinux.org/RPi_Hardware>.
27. 27
"Statistical Snapshots from the American Foundation for the Blind." AFB.org. American
Foundation for the Blind. 26 Dec. 2014. <http://www.afb.org/info/blindness-
statistics/2>.
"UCSB Personal Guidance System." UCSB Personal Guidance System. 04 Mar. 2014.
<http://www.geog.ucsb.edu/pgs/main.htm>.
"Ultrasonic and Infrared Sensor Comparison." Raspberry Pi. 04 Jan. 2014
<http://www.raspberrypi.org/phpBB3/viewtopic.php?f=37&t=59709>.
"Ultrasonic Sensors." Ultrasonic Sensors. 04 Jan. 2014.
<http://learn.cs2n.org/solt/lessons/nvt2.0/content/resources/helpers/nxt_sensors/ultr
asonic.html>.
28. 28
Final Design Evaluation___________________
This design is able to detect how far the nearest object is to the user and report it to a
smartphone, which relays the information to a headset. It is simple, but very powerful because
it provides a solution that is both useful and affordable.
An advantage to this design is that it integrates the use of a smartphone, an everyday device
that has great functionality. Through a smartphone, we can deliver updates to the app and add
features without directly changing the device itself.
A downside to the use of the smartphone though is that it creates a dependency not only on
the smartphone but also on another person. This is especially problematic to a blind person so
we designed another solution using the raspberry pi. Although it is bigger and does not have
the capabilities of a smartphone, the raspberry pi can do all the basic functionality by itself, that
is, without the need for an external device.
Indubitably, our design is not perfect and can be improved in many ways. Using graphical
analysis tools and an added camera, we could have added functionality to distinguish between
the types of objects and determine which side objects are detected and issue an alert
appropriately. We could also potentially distinguish between humans or other animals and
inanimate objects using an infrared sensor. The Arduino offers limitless possibilities to
connecting the real world with technology, but since this is a prototype we decided to focus on
the basics, one of which was making a system that can accurately measure and convey
distances to the nearest object. A current update that we plan on attending to is the addition of
a feature that accounts for the Doppler effect, and a feature that increases battery life and
decreases energy consumption of the system.
This design is not intended to revolutionize the way blind people live their lives or go about
from place to place. Rather it is supposed to be a cost-efficient supplement to what they
already use in their daily routine. The apparatus is meant to be used in concert with blind canes.
This would allow for the user to feel more secure by extending his or her range of sensitivity.
Allowing the user to feel more comfortable moving around is the sole purpose and drive of this
project, and it has been throughout the creation process.
