Bluetooth Enabled
Lightsaber
Team # 32
Team Members:
Shayna Kapadia
Tulika Gupta
Kushal Majmundar
TA:
Chi Zheng
Table of Contents
Introduction 4
Problem Background 4
Solution Overview 5
Visual Aid 7
High Level Requirements 8
Design 9
Block Diagram 9
Physical Design 10
Sensor Subsystem 12
Snap Switches 12
Processing Subsystem 13
Microcontroller 13
Power Subsystem 14
Lithium Ion Battery 14
Voltage Regulator 1 15
Voltage Regulator 2 15
Audio Visual Subsystem 16
LCD Screen 16
Programmable LEDs 16
Speaker 17
Buttons 18
Schematics 19
Tolerance Analysis 21
Differences 24
Overview 24
Analysis 25
Cost Analysis 27
2
1. Introduction
1.1. Problem Background
The toy industry is extremely large, reaching $90.4 billion dollars
[6]
a year
in global revenue. On average, parents will spend around $250
[6]
on toys
every year for each child. With technology advancing, there comes the
opportunity to create toys that are more interactive; however as toys
become more innovative with added technology, they lose their
affordability. Interactive entertainment for children needs to be more
affordable while also maintaining the benefits that added technology can
provide, such as customization. We also need these toys to be portable
without an excessive number of add-ons, since they would increase the
prices and also reduce the portability.
In Spring 2019, Project #8 : Wirelessly synchronizing LED Mickey Mouse
Ears sought to create affordable and entertaining devices for families to
use to enjoy with customizable light patterns.
We strive to create a different solution to the problem that the project we
were inspired by was trying to solve. Our solution is to create Star Wars
Lightsabers which can be programmed to connect to each other and with
several characteristics to make them more customizable to the player.
The lightsaber toys sold by Disney fail to provide an interactive
experience. While they do light up and play sounds, they do not interact
with each other, and they are not customizable
[7]
. In terms of affordability,
while they do have options that are fairly priced at $32.99, these options
do not provide any customization. Our product allows a user to not only
interact with other users through gameplay, but also to customize their
own experience by choosing a character, allowing their lightsabers to show
varied light and audio displays that are not limited to one color or one
sound.
4
1.2. Solution Overview
We strive to create a different solution to the affordable entertainment
problem that the project we were inspired by was trying to solve.
Our solution is to create Star Wars Lightsabers which can be programmed
to connect to each other and with several characteristics to make them
more customizable to the player.
Each Lightsaber will allow the user to choose a character, and each
character has a corresponding set of effects. Whenever the lightsabers
collide, they will produce a light sequence and a clashing sound effect.
Both the light and sound effects will be different for each character
available.
Before gameplay, the Lightsabers will pair with each other through
Bluetooth so both players cannot have the same character and so the
lightsabers can be synchronized.
During game play, the Lightsaber detects a hit due to the switches present
around the base connecting the top of the sword to the hilt. These
switches have longer triggers and are arranged in a circular manner around
the base. (Fig. 3) Since the material of the sword is a light plastic, it would
move into the trigger during the hit, and trigger the switch, which would
send in a signal registering a hit. This hit signal is sent to the next
Lightsaber via Bluetooth.
If both lightsabers register a hit signal within a certain time frame, then we
know that the lightsabers have had a saber-to-saber collision, and neither
player is awarded a hit point.
However, if only one of the lightsabers registers a hit within the time
frame, it will register as a saber-to-person hit; and a hit point will be
rewarded. The game ends after one player has reached 100 points, with
each hit giving the player 10 points.
5
In order to keep the game affordable and to not overly complicate the
gameplay, we plan on having some basic rules for playing. While there
may be a different way to check if the users are making contact with each
other, such as a specific target on the players, we choose to implement the
following rules instead, for the sake of portability and avoiding having too
many parts. This will ensure the players can have fun and stay safe while
playing the game.
Rules of gameplay:
●Parental supervision is required for children under the age of 10 to
prevent safety hazards.
●Players must touch each other and not random objects to gain points.
●Players must wear full sleeves and long pants.
The physical design of the lightsaber will be made of a lightweight plastic,
similar to plastics that are used in many toys. This will prevent any serious
injuries that could come along with having a heavier material.
6
1.3. Visual Aid
Figure 1: Game Setup
Figure 2: Lightsaber-Lightsaber Collision (+0 Points)
Figure 3: Successful “Hit” to Right Player (+10 Points)
7
1.4. High Level Requirements
1. The switches must trigger upon hit and have an error rate of less than
10%
2. Once a hit is registered on one or both devices, the other should detect
the hit within 10ms for the score update to be instantaneous.
3. The light and sound effects should begin within 1 second of the
collision and should correspond to the character.
8
2. Design
2.1. Block Diagram
Figure 4: Block Diagram
9
2.2. Physical Design
Figure 5: Upper View Lightsaber Internals
10
Figure 6: Internals of Outer Handle
11
2.3. Sensor Subsystem
The sensor subsystem is responsible for detecting when the lightsaber has
made contact with another object. This is accomplished via a set of
switches surrounding the base of the lightsaber blade. When the lightsaber
blade makes contact with another object, the blade will be slightly pushed
due to the impact, this will cause the base of the blade to trigger one or
more of the surrounding switches. Therefore, whenever the lightsaber
makes contact with another object a switch will be triggered; thus
detecting when the lightsaber has made contact. The buttons will then
send the detection signals to the processing subsystem.
2.3.1. Snap Switches
There will be four snap switches surrounding the base of the
lightsaber blade as seen in figure 3.
Requirement
Verification
The switches should only trigger after the
lightsaber has had an impact.
1. Once the switches are connected
to the microcontroller we can
monitor if they are detecting
impact.
2. Hit the lightsaber against an object
from six different angles to see if
the switch gets triggered from an
impact.
3. Swing the lightsaber around in all
directions without hitting
anything, and ensure sure the
switches do not get triggered
without an impact.
4. Verify that the switches only
trigger from an impact.
Table 1: Snap Switch R&V
12
2.4. Processing Subsystem
The Processing Subsystem is tasked with
(1) receiving hit signals from the Sensor Subsystem,
(2) sending and receiving bluetooth signals to/from the paired lightsaber
(3) instructing the Audio Visual System on what to display and what
sound and lights to produce
2.4.1. Microcontroller
We will be using an ESP32 WROOM-32D as our microcontroller.
We will be using its bluetooth capabilities to send and receive
signals from the other paired lightsaber. It will also send signals to
the peripherals to instruct them on what to do.
Requirement
Verification
1. A hit signal should be
able to be sent from one
processing system to the
other in 10 ms.
2. Can send and receive
data successfully from
multiple sources and
destinations
1.
a. Connect ESP-32 to power and
upload arduino program to send a 30
byte packet to computer
b. Set rate to be 38400 bps
c. Confirm packets received on
computer end
2.
a. Connect microcontroller to LCD
Screen and Buttons
b. Confirm that information can be
received from buttons and changes are
reflected in LCD Screen
c. Connect microcontroller to LED
Strips next and confirm information
of LCD Screen changes LED colors.
Table 2: Microcontroller R&V
13
2.5. Power Subsystem
The power subsystem is responsible for providing and regulating power
for the Microcontroller (ESP32), LCD Screen, Programmable LEDs, and
Speaker. The power subsystem consists of a 7.2V lithium-ion battery
attached to two voltage regulator circuits. The LED strips, switches, and
speaker require a consistent voltage of 5 V, while the LCD Screen and ESP
32 require 3.3 V. Thus we need two voltage regulator circuits, one that
outputs a steady 5 V and one that outputs a steady 3.3 V. The total
current draw for all the components needing power falls into the range
603.16 - 603.22 mA . These calculations are based on the power
consumption of the ESP-32 (500 mA), LED Strips (1 µA), LCD Screen
(160-220 μA), Speaker (100mA), and Switches (3mA) datasheets. Since
the battery has a wattage of 3350 mAh, we can calculate the hours of
battery life our product can sustain, which would be 5.55 hours.
2.5.1. Lithium Ion Battery
A 7.2V lithium-ion battery will be used to supply power for all of
the components.
Requirement
Verification
1. The 7.2V lithium-ion battery
should last at least 5 hours
1. Connect battery to a voltmeter
2. Plot voltage over span of 5 hours
3. Ensure voltage levels do not drop
below 5 V over this timeframe
Table 3: Battery R&V
14
2.5.2. Voltage Regulator 1
A voltage regulator will be attached to the lithium-ion battery in
order to regulate the supply voltage and ensure that it never exceeds
5V.
Requirement
Verification
1. Voltage supply should be
maintained at 5 0.2 V±
1.
a. Connect the voltage
regulator circuit to a power
supply at 7.2V to mimic the
battery.
b. Use a voltmeter to monitor
the voltage.
c. Ensure the output voltage
remains around 4.8 - 5.2 V
Table 4: Voltage Regulator 1 R&V
2.5.3. Voltage Regulator 2
A voltage regulator will be attached to the lithium-ion battery in
order to regulate the supply voltage and ensure that it never exceeds
3.3V.
Requirement
Verification
1. Voltage supply should be
maintained at 3.3 0.2 V±
1.
a. Connect the voltage
regulator circuit to a power
supply at 7.2V to mimic the
battery.
b. Use a voltmeter to monitor
the voltage.
c. Ensure the output voltage
remains around 3.1 - 3.5 V
Table 5: Voltage Regulator 2 R&V
15
2.6. Audio Visual Subsystem
The audio visual subsystem provides the interactive elements for the user.
We begin with the LCD Screen and the buttons. The LCD Screen will
consist of text options to let the user choose their character as well as
display the score. There will be buttons below the screen to allow the user
to choose said character or to restart the game.
Upon the selection of the character, the information will be sent to the
processing subsystem. Now upon a hit, since a character has been
registered, the programmable LEDs and speakers will react accordingly
with the pre-assigned sound and light sequences.
2.6.1. LCD Screen
A simple LCD screen capable of showing two lines of text, the first
with the character name and scrolling arrows on either side, and the
next to display the score. It will be connected to the buttons and to
the processing subsystem.
Requirement
Verification
1. No inconsistencies in display,
should display text completely
upto maximum character limit (16
characters).
2. Change in values must be
registered and displayed.
1. Send in a 16 character word,
ensure proper display.
2. Send data in a loop, changing
values every 1 second. Ensure that
changing values are observed.
[5]
Table 6: LCD Screen R&V
2.6.2. Programmable LEDs
LED strips are convenient since light sequences can be well
programmed and every LED is programmable. As a result, we will
be able to provide quality entertainment with multicolor LED
strips and lighting patterns. The LEDs will be connected to the
processing subsystem as well as the power subsystem.
16
Requirement
Verification
1. LED strips must be able to display
a sequence of lights.
2. LEDs must respond to a hit within
a delay of 1 second.
1.
a. Connect the strips to a
microcontroller and send in
a changing color pattern.
b. Observe fading and overall
pleasant viewing and make
sure there is no rapid or
inconsistent blinking of
lights.
2.
a. Provide test code and print
time delay from receiving
value till change in LED.
Table 7: LEDs R&V
2.6.3. Speaker
A speaker should be able to play sounds as soon as a hit is registered.
It will also be connected to both the processing and the power
subsystem.
Requirement
Verification
1. To be able to play a small tune
upon hit.
1. Create a code to provide
pre-selected notes and ensure they
can be played in a sequence.
Table 8: Speaker R&V
2.6.4. Buttons
We require 2 push buttons, one to scroll to the right to choose a
character, and another to start/restart the game. These will be
connected to the processing subsystem.
17
Requirement
Verification
1. The push of a button should be
registered by the processing
subsystem.
1.
a. Verify button connections
by connecting to any
microcontroller and
receiving confirmation.
b. Connect to a working
processing subsystem and
print when pressed.
Table 9: Buttons R&V
2.7. Schematics
Figure 7: LCD Display Schematic
18
Figure 8: Microcontroller Schematic
Figure 9: 3.3V Voltage Regulator Schematic
19
2.8. Tolerance Analysis
The snap switches we are using have an operating force of 1.47 N. This
means it requires 1.47 N of force to trigger the switch, and in our case,
send a signal to the processing subsystem that there has been a collision.
Using Newton’s laws of physics, we can calculate what acceleration is
needed to produce enough force to trigger the switch without a collision.
Knowing that the base of the lightsaber is heavier than the blade, and that
the blade is made of a thinner and lighter plastic material, we estimate the
weight of the blade to be 0.03 kg.
___(2.8.1 Eq1)F = m × a
___(2.8.2 Eq2).47 N 0.029kg a1 = ×
___(2.8.2 Eq3)0.7 m/s a5
2
=
In order to trigger the switches without a collision, a person would need to
swing the lightsaber with an acceleration of at least 50.7 m/s
2
. A person of
height 4’10’’ weighing in around 40 kg (similar to a young child), can
move their arm at an average rate of 5.74m/s
2
(according to our trials
noted below). As a player moves around, swinging the lightsaber, but not
hitting anything, there should not be enough force to trigger the switches
unless there is a physical collision that provides the extra force needed to
exceed 1.47 N.
Now we will calculate the force exerted on a lightsaber during a collision.
Firstly, we know that the work done by the lightsaber will be equal to the
kinetic energy. For this calculation, we will assume that the lightsaber is
swung horizontally.
___(2.8.2 Eq4) EW = K
___(2.8.2 Eq5) W = F × d
We also know that:
20
___(2.8.2 Eq6)E mv K =
2
1
2
Thus, we can say that:
___(2.8.2 Eq7)F mv × d =
2
1
2
___(2.8.2 Eq8)
√
m
2F d
= v
We assume that upon collision, the lightsabers will move between 5-15 cm
(0.05 m- 0.15 m)from the position of the original collision. We also
assume that the lightsaber will be colliding with an unmoving target.
We know that the force needed must exceed 1.47 N. Now let’s calculate
the velocity needed in order to provide that force.
___(2.8.2 Eq9)
.25 m/s v =
√
0.029
2(1.47N)(0.05 m)
= 2
__(2.8.2 Eq10)
.89 m/s v =
√
0.029
2(1.47N)(0.15 m)
= 3
This means, in order to provide the force necessary to trigger the switches
on collision, the lightsaber would need to be moving around 0.76 - 1.33
m/s at a minimum. Seeing that the average acceleration of a swinging arm
is 5.74 m/s
2
, It would only take a user at least 0.39-0.68 s to accelerate to
that speed, which is a reasonable amount of time to make a swing.
___(2.8.2 Eq11)tv = a
___(2.8.2 Eq12)
v
a
= t
___(2.8.2 Eq13).39 s
2.25 m/s
5.74 m/s
2
= 0
___(2.8.2 Eq14).68 s
3.89 m/s
5.74 m/s
2
= 0
In reality, a user may go into a collision at a much higher velocity, so it is
reasonable to assume that upon any intended collision, a user will in fact
trigger the switches, and this a hit signal.
…
In order to provide some data on the force at which an average child can
swing their arm, we conducted some trials in our apartment. Since we are
quarantined, and we do not have access to proper tools, we made do with
21
a measuring tape and a timer to measure and calculate the average
acceleration a child-sized person can swing their arm. Because Tulika is
child sized, she served as an ideal subject for these trials.
___(2.8.2 Eq13) v at x =
0
+
2
1
2
Since we started each trail with an initial velocity of 0 m/s. This equation
reduces to:
___(2.8.2 Eq14) x at =
2
1
2
Thus, ___(2.8.2 Eq15)
t
2
2x
= a
Trial #
Distance
Time
Acceleration
1
1.22 m
0.89 s
3.08 m/s
2
2
1.22 m
0.53 s
8.68 m/ s
2
3
1.22 m
0.62 s
6.34 m/ s
2
4
1.22 m
0.71 s
4.84 m/ s
2
Average
5.74 m/ s
2
Table 10: Trials for average acceleration
22
3. Differences
3.1. Overview
The problem statement itself was a broad opportunity to create an
entertaining and interactive device.
The project before us, Mickey Mouse Ears, aimed to create a wearable set
of headbands with mickey mouse ears on them. These ears could be
programmed by an app on the user’s phone and would then light up
according to the user’s choice of lights. In addition, these lights could
synchronize with the rest and all the headbands would go through the
light patterns synchronously.
The Lightsaber improves on the Mickey Mouse Ears in many ways.
Our project aims to create an interactive game with a set of lightsabers.
These lightsabers interact with each other to keep track of who has been
hit, and what the scores are so far. In addition, the user can select a
character and the other user can choose a different character. Each
character comes with a personalized light and sound sequence, which will
be chosen with reference to Disney’s Star Wars movies.
The Lightsabers have added entertainment values by the sound effects, the
interactivity as they come in the form of a game, and in providing the user
an option for the users to choose characters they are familiar with.
The largest trade off is that Mickey mouse ears do provide more
entertainment to children who are less than 10 years old, as it has less
safety requirements. On the other hand, to children above 10 years of age,
a game they can interact and run around with might prove to be more
enjoyable, and when the rules are followed, provides no risk.
23
3.2. Analysis
The core problem to be solved was a lack of quality entertainment. We
break this down into a set of qualities: interactiveness, affordability and
portability. Based on these qualifications, the previous project provided
light effects on a headband, where the light effects were customizable.
We chose to improve the factor of interactiveness, where we shaped the
product to be a game so the users can enjoy themselves, with added LCD
screens and light and sounds and characters. The following table
highlights the features offered by each of the solutions. This table serves to
show that the interactivity of the Bluetooth Enabled Lightsabers is far
higher.
Feature
Bluetooth Enabled
Lightsabers
Mickey Mouse Ears
Inter-device
connectability
Yes
Yes
Customizable Light
Patterns
Yes
Yes
Customizable Sound
Effects
Yes
No
App based
interactivity with user
No
Yes
Character
customization
Yes
No
Score keeping
Yes
No
Interactive on-device
screen
Yes
No
Table 11: Feature list for original and new projects
24
Both projects are extremely portable. The Bluetooth Enabled Lightsaber
weighs 0.25 kg (Lightsaber frame: 0.0816 kg, battery: 0.1 kg and LEDs:
0.068 kg), while the Mickey Mouse Ears weight 0.16 kg
[8]
(Mentioned: 52
g for battery and 120 g for headband). Since each has a different use, the
weights are not entirely comparable. Both these weights are easily held by a
child of about 10 years old.
In terms of affordability, the cost of making the Mickey Mouse Ears
would come up to $97
[8]
and the Bluetooth Enabled Lightsaber would
cost about $96, and thus these are very comparable. Buying the
components in bulk would reduce these prices to less than half the price.
In this case, the prices of the original Lightsabers would be within $10 of
the Bluetooth Enabled Lightsabers, which is acceptable since they are
made up for in the additions in the number of features.
25
4. Cost Analysis
4.1. Labor
● Labor: (For each partner in the project)
○ A Computer Engineering Major from the University of Illinois at Urbana
Champaign makes an average salary of $84,250 a year
[4]
○ This is about $40.5 per hour, which is our chosen labor cost
○ Estimated work time is 5 hours/week for 15 weeks, which is 75 hours to
complete.
○ With the given equation, cost per hour x 2.5 x hours to complete =
TOTAL:
■ $40.5/hour x 2.5 x 75 hours = $ 7593.7
● Labor for all the partners in the project:
○ $ 7593.7/partner x 3 partners = $22,781.25
● So, our final estimated cost of labor is $22,781.25
26
4.2. Parts
Part
Manufacturer
Part #
Quantity
Total Cost ($)
Snap Switch
Omron
Electronics
Inc-EMC Div
SW1046TR-N
D
4
$8.04
ESP32 WiFi
Module
Espressif
Systems
1904-1025-1-N
D
1
$4.50
LCD Screen
Seeed
Technology
Co., Ltd
1597-1040202
08-ND
1
$3.98
Speaker
CUI Devices
102-3851-ND
1
$3.61
Programmable
LED Strips
HKBAYI
WS2812B
1
$22.99
Lightsaber
Disney
B2915AS0
1
$19.99
Battery
Jauch Quartz
1908-1346-ND
1
$28.08
Total:
$91.19
Table 12: Cost Analysis
4.3. Total Costs
● Total Costs
= Labor + Parts
= $22,781.25 + $95.69
= $22,876.94
27
5. Schedule
Week
Kushal
Shayna
Tulika
1.
Place order for parts
Research and understand
PCB design requirements
and specifications
Research and understand
PCB design requirements
and specifications
2.
Talk to Machine Shop
about modifying
lightsaber to fit our
components
Design the PCB layout for
the Processing Subsystem
Design the PCB layout for
the Sensor Subsystem
3.
Design the PCB layout
for the Power Subsystem
Design the PCB layout for
the Audio/Visual Subsystem
Design the PCB layout for
the Audio/Visual Subsystem
4.
Test for confirmation of
sensor subsystem r/v
Test for confirmation of
A/V subsystem r/v
Finalize PCB Layout and put
in order request for PCB
5.
Program microcontroller
to send hit signal upon
triggering of switch
Begin fitting parts into the
handle base
Once the PCB arries, begin
soldering the components
onto it
6.
Program game logic onto
microcontroller
Fit PCB and rest of
components into the
lightsaber
Begin initial test for
confirmation of processing
subsystem r/v
7.
Fit PCB and rest of
components into the
lightsaber
Fit PCB and rest of
components into the
lightsaber
Program peripheral control
onto the microcontroller (lcd
display, speaker, and leds)
8.
Refine and test, catch up
if fallen behind schedule
Refine and test, catch up if
fallen behind schedule
Refine and test, catch up if
fallen behind schedule
9.
Final Demo, work on
final presentation
Final Demo, work on final
presentation
Final Demo, work on final
presentation
10.
Final Presentation
Final Presentation
Final Presentation
Table 13: Schedule
28
6. Ethics and Safety
6.1. Ethics
We do believe our product is both ethical and safe to use, if used properly
under the conditions we have stated in our background section. One
ethical consideration we do have would be players intentions for playing
this game. IEEE Code of Ethics number 9 states that we should “avoid
injuring others, their property, reputation, or employment by false or
malicious action.” While our game is a mock fighting game, it is not
intended to facilitate violence or injury. We aim to make the lightsaber out
of a lightweight plastic so that it cannot be used to seriously injure any of
the participants. Though we understand that young children often do not
know these limits, and that is why we have put an age restriction and also
advise parental guidance. This can ensure that young children do not
injure each other while playing this game. All other codes in the IEEE
Code of Ethics we believe we comply fully with.
6.2. Safety
In terms of safety, we have similar concerns mainly with the intent of the
players and also the age. While we cannot control the intent of the players,
we have placed restrictions on age and parental supervision for young
people who will likely accidentally cause harm to themselves or the other
player. We have also said that we will make the lightsaber very lightweight
so that it cannot cause much physical injury. Another safety concern we
have is with the battery If the battery were to fail or overheat, this would
result in “thermal runaway which is a reaction within the battery causing
internal temperature and pressure to rise at a quicker rate then can be
dissipated”. Once a battery goes into thermal runway, it can cause enough
heat to induce thermal runway in other batteries ultimately resulting in a
fire. These fires are more difficult to put out and thus make this uniquely
dangerous
[2]
. Other safety concerns could arise from open or uncovered
wires that could potentially cause electric shock to the wearer of the
device
[3]
. This is why our design will have all wires covered and away from
29
the handle of the lightsaber; thus adhering to the first rule of the IEEE
code of ethics
[1]
by ensuring the safety of the user.
30
7. Risk Analysis
Of all our subsystems, the processing subsystem possesses the highest risk. The
processing subsystem is charged with receiving the signals from the trigger
switches and immediately sending output signals to the audio visual subsystem
all within a very small delay. It also has to send a hit signal via bluetooth to the
other lightsaber, so it can also send a signal to its own audio visual subsystem.
This bluetooth communication is where our highest risk lies. If the
communication fails, if the pairing drops, or if the signal is not sent fast enough,
there will be audible and visual delays in the sound and light effects that will
negatively impact the performance of the product and also customer satisfaction.
31
8. Citations
[1] “IEEE Code of Ethics”, ieee.org. 2020. [Online]. Available:
https://www.ieee.org/about/corporate/governance/p7-8.html.[Accessed: 17-
April- 2020]
[2] “Lithium Ion Battery Safety for Consumers,” Lithium Ion Battery Safety for
Consumers. NFPA, 2017. Available:
https://www.nfpa.org/-/media/Files/Public-Education/Resources/Safety-tip-sh
eets/LithiumIonBatterySafety.ashx [Accessed: 17- April- 2020]
[3] “The Hazards of Lithium Batteries”, Viceprovost.tufts.edu.(2020). [Online].
Available:
https://viceprovost.tufts.edu//ehs/files/The-Hazards-of-Lithium-Batteries.pdf
[Accessed: 17- April- 2020].
[4] E. I. T. S. Services, “Salary Averages,” Salary Averages :: ECE ILLINOIS.
[Online]. Available:
https://ece.illinois.edu/admissions/why-ece/salary-averages.asp. [Accessed: 17-
April- 2020].
[5] Basic Character LCD Hookup Guide. Sparkfun. [Online] Available:
https://learn.sparkfun.com/tutorials/basic-character-lcd-hookup-guide.
[Accessed April 17, 2020. ]
[6] E. Duncan, “Topic: Toy Industry,” www.statista.com. [Online]. Available:
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