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I. Introduction
Microcontrollers play a huge role in the electronics world. Electronics
hobbyists, students and enthusiasts alike use microcontrollers for their own
project making. This is because microcontrollers make circuit making easier
since it uses user coded programs. Microcontrollers are even implemented in
schools. For example, in the University of Mindanao, students in the fields of
computer, electrical, electronic engineering and even computing education use
microcontrollers and these play a huge role in the course syllabus. Currently,
students use the Programmable Interface Controller (PICs) made by Microchip
Technologies. It is great but it is becoming outdated due to the demands of
users to include more features. The Arduino is an example of what the users
want. It has a lot of features compared to PICs and has an extensive range of
tutorials online. Due to the popularity of single-board microcontrollers, many
companies have created single-board computers that can what recreate
microcontrollers do and also which have fast computing capabilities. An
example of this is the Raspberry Pi.
The Raspberry Pi is an inexpensive microcomputer and can work
together with the outside world. It can be used to make electronic projects and
users can learn the Python programming language. From what the researchers
learned from a survey of the theses section in the library, out of fifty researches
in 2009-2014, only twenty-eight have used microcontrollers; only two have
used the Arduino platform and no one used the Raspberry Pi. This is due to the
students having little to no knowledge of the Raspberry Pi. The students are not
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exposed to new technology and therefore are lagging behind. The introduction
of Arduino is a good start but it is not enough. If there are new technologies, it
should be slowly implemented.
The student’s education will improve if new technologies are introduced
(Rajadel, 2016). The introduction of Raspberry Pi is a good start. Thus,
developing a laboratory circuit trainer based on Raspberry Pi will not only
widen the knowledge of the students but also help them be more competitive.
II. Objectives of the Study
This study aimed to develop a Raspberry Pi Laboratory Circuit Trainer.
Specifically, the researchers aim to achieve the following objectives:
1. To develop a circuit trainer capable of performing different kinds of
laboratory experiments using the platform of Raspberry Pi.
2. To conduct a function test on various modules and components
included in the trainer in terms of:
a. General-Purpose Input/Output (GPIO)
b. Interfacing
c. Data communications
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III. Significance of the Study
The development of the Raspberry Pi Laboratory circuit trainer is a new
way of introducing an interactive instructional device that will benefit the
students and teachers of the University of Mindanao for courses that involve
programming and circuit design. With this circuit trainer, we won’t be needing
a desktop computer that is bulky. In comparison, the Raspberry Pi is just a
microcomputer comparable to the size of a credit card and which only needs a
low power source. Due to the cheap price of the minicomputer, students won’t
have to worry breaking it during experiments. In the near future, single board
computers will become a hype and will be used by many, so, Raspberry Pi is a
good introduction to create and build educational exercises and projects.
IV. Target Beneficiaries
The researchers aimed to develop a Raspberry Pi laboratory circuit
trainer which can be used in three engineering courses of the University of
Mindanao mainly the computer, electrical and electronics engineering. Through
this, the proposed study should benefit the following:
Students. The circuit trainer will be able to develop student’s technical
and academic expertise when it comes to programming and circuit designing.
While doing some of the laboratory exercises or after its completion, students
will able to build or create other designs or projects which may further develop
their academic skills.
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Professors. Professors will also benefit from this project. Since the
traditional way of teaching is through theory, professors could use the trainers
to demonstrate the theories discussed.
V. Review of Related Literature
This section provides related views and literatures from different
sources like books, magazines, dissertations and journals which have been
helpful in the making of the circuit trainer. The following contents has
connection with the current project being studied by the researchers.
Laboratory trainer
According to Cuzon, et. al. (2014), a laboratory trainer is a training
equipment comprised of several circuit components used to control loads
electronically. It is regularly used in schools to teach the basic principles of the
field of study. Equipment used for teaching electronics can be traced back to
the start of twentieth century. It didn’t take too long before training schools and
creators embedded breadboards into enclosures that contains onboard power
supplies, function and pulse generators, switches, LED indicators, and many
other regularly used apparatus. Currently, single breadboards may be bought
starting at under $10 with training or design kits having embedded generators,
power supplies, and many up-to-date features up to hundreds of dollars.
Nevertheless, these kits are cheaper and take much less bench space than
having each piece of gear. A secondhand analog or digital trainer is a great
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add-on to a hobbyist's bench (Johnson, 2013). Shown in Figure 1 is an example
of a trainer (http://www.electronicproducts.com).
Figure 1. An analog/digital trainer
According to Kadiri et. al. (2014), the development of an inexpensive
and innovated digital electronic training module fabricated using components
found in the local setting had proved that the trainer is useful for experiments in
a starting course in digital logic design, an essential course in most electrical
and computer engineering programs offered in their college, Federal
Polytechnic, Offa of Nigeria. Hacker (2009) also conducted a study on lowcost digital trainer using a parallel printer port as a communication device
between the computer and the circuit board. He concluded that the
implementation of the low-cost trainer he named PortBuffer had significant
benefits in a student’s education. It was explored by the students during the
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author’s Digital Electronic course. The student feedback was significantly
favorable, and strengthened the PortBuffer’s role as a valuable teaching
resource.
Raspberry Pi
The Raspberry Pi are comprised of economical, credit card sized,
microcomputers created by the Raspberry Pi Foundation in the United
Kingdom. The foundation's purpose of making the microcomputer was to
endorse the teaching of basic computer skills in schools. The expansion of the
Raspberry Pi has penetrated the market of embedded systems and research
(Pajankar, 2015). According to Rouse (2012), the Raspberry Pi’s size is
comparable to that of a credit card, has a 32-bit Advanced RISC Machines
(ARM) processor and uses a Raspbian distribution of Linux for its operating
system (OS). Python or any other programming language that will compile for
ARM v6 and v7 can be used in the Raspberry Pi. The Raspberry Pi in principle
is a system-on-a-chip (SoC) minicomputer that has ports. It can be used by
attaching up a USB keyboard and plugging the computer into an HDMI ready
monitor or television.
The introduction of Raspberry Pi has been successful. It has been
introduced mainly in schools to introduce coding and electronic component
manipulation to students. University of Cambridge researchers Dr. Maximilian
Bock and Aftab Jalia were given support by the Raspberry Pi Foundation for a
starting project exploring the potentials of giving computer access and
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education in Indian rural schools. They led two workshops in June 2014 with
the help of local organizations teaching computing using the Raspberry Pi.
Raspberry Pis and peripherals were used in the workshops and were handed
over to the organizations. The Cambridge team’s inexpensive engineering
approach, bringing computing education without the need for complicated
infrastructure, proved very effective in Indian rural schools (Lynn, 2014).
15,000 free microcomputers were given to schools around the UK, with a view
to bringing forth a new generation of computer scientists. The Raspberry Pi
Foundation expects the low cost computers will motivate children to start
coding, this being sponsored by Google. The first simple Raspberry Pi,
launched in 2012, was a huge success (Wakefield and Rich, 2013). Shown in
Figure 2 is a comparison of different Raspberry Pi models compared from
Model A to Model B+ (http://tinkersphere.com).
Figure 2. Different Raspberry Pi Models Compared
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Raspberry Pi 2 Model B
As of 2015, the Raspberry Pi 2 Model B is the most powerful Pi found
in the market. The Raspberry Pi 2 is the one that is most fit for non-experts
(Newell, 2015), and offers a cruical upgrade in functions compared to the
previous versions, and signifies the first time the company has upgraded the
computer’s central processing unit (CPU). The Raspberry Pi 2 is multi-cored,
with a 900 megahertz quad-core processor. It's also has 1 gigabyte of RAM,
double that of its predecesors and USB ports that can now supply up to 1.2A of
current, perfect for more power-hungry components (Bray, 2015). Shown in
Figure 3 is the Raspberry Pi 2 Model B introduced in February 2015
(https://www.raspberrypi.org).
Figure 3. The Raspberry Pi 2 Model B
The microcomputer uses the same VideoCore IV 3D graphics processor,
the same with its predecesors, with full 1080p video output capabilities. The
Raspberry Pi 2 contains an Ethernet port, a 3.5mm combined audio and video
jack, a micro-SD card slot and an HDMI port. Users will be grateful for the 40
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GPIO pins (Model B had 24), camera serial interface (CSI) and digital serial
interface (DSI) connectors for straight through connections to expansion
boards, displays, and others (Chacos, 2015). Even with the huge upgrade in
capabilities, the Raspberry Pi 2 remains backwards compatible with earlier
Raspberry Pi hardware and software projects, so for upgraders, the shift will
not be difficult. Most users will only want to download a new Raspbian OS that
is ARMv7 compatible (Bray, 2015).
Raspberry Pi (General Purpose Input/Output) GPIO
One of the powerful features of the Raspberry Pi is the GPIO. These are
usually represented by pinheaders or pins. These pins link Raspberry Pi to the
external world (sensors, motors, etc). Raspberry Pi Models A and B have 26
pins while models B+ and B2 have 40 pins. The models B+ and B2’s pins are
backwards compatible with models A and B (Prasad, 2014). Users can turn on
or off LEDs, make a motor spin, or read a pressed button because of the
Raspberry Pi’s biderectional GPIO. Driving the Raspberry Pi’s I/O lines
requires a bit of programming (Lindblom and Taylor, 2015).
According to Dee (2015), the Raspberry Pi GPIO operates at 3.3 volts,
which is unusual since many devices (such as sensors, logic and functional
chips) run on 5 volts. A lot of Raspberry Pi support forums recommend the use
of dividers and level shifters when interfacing 5 volt devices with the
Raspberry Pi. Also, according to geeks3d.com (2015), users have to take note
of the max current intensity that can be sent by the pins. This is crucial if users
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don’t want to damage the Raspberry Pi board. Also, the 3.3V power supply can
only send up to 50mA (or 0.165W which is really low). 50mA is the total
current intensity for all pins all together. A single pin can send from 2mA to
16mA. It’s not suggested to use a lot of current from the pins. The Raspberry Pi
GPIO wasn’t developed to have a large power output and should only be used
to send or receive information. Meaning, users have to connect the GPIO and
the final device through an amplifer. Users, for example, should not control a
small motor with a GPIO pin directly. To control a small motor, users should
use some transistors and resistors or use drivers. The usual rule is to maximize
the current to the lowest probable value (3mA or lower). Shown in Figure 4 are
the Raspberry Pi Model A and B’s physical pins and pin configuration
(http://elinux.org). Shown in Figure 5 are the Raspberry Pi Model A+, B+ and
2’s physical pins and pin configuration (http://elinux.org).
Figure 4. Raspberry Pi A and B Pin Configuration
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Figure 5. Raspberry Pi A+, B+ and 2 Pin Configuration
Raspbian (Operating System)
Raspbian has been the default distribution (distro) for the Raspberry Pi
since its launch in 2012 (Pounder, 2016). According to Thomas (2014),
Raspbian is based on Debian, which is a Linux distribution. It’s called
Raspbian because it’s a portmanteau of Raspberry and Debian. Shown in
Figure 6 is the Raspbian desktop (http://www.mbtechworks.com).
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Figure 6. Raspbian Desktop Environment
The Raspbian operating system is one of the most popular operating
system that Raspberry Pi uses. Raspbian is an unofficial variant of Debian
Wheezy that is compiled to run on Raspberry Pi computers. Raspbian is more
than a pure operating system. It contains over thirty-five thousand (35,000)
packages and precompiled software compatible with the Raspberry Pi
(Pajankar, 2015). According to Calin (2015), Raspbian is an operating system
that is simple to use and has a lot of support around the world. The Raspbian
OS is simple and common. Also, it is the greatest platform for teaching novices
to work with the Raspberry Pi. Once the user becomes familiar with the
operating, it will be like riding a bike; users will not forget how to do it. The
Raspbian features include multimedia and graphics packages as primary
software, and if users need more for the Raspberry Pi, they can add additional
software like browsers, messaging apps, office software, etc.
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Sensors
Sensors are complex devices that are regularly used to sense and reply to
electrical or optical signals (engineersgarage.com, 2011). In essence, a sensor
takes a physical property like temperature and changes it to an electrical signal
that controllers can interpret. Robotics rely on sensors mainly on two reasons.
First, robots are more autonomous because of how now it can perceive its own
environment and make decisions through programming based on what it
perceived. Second, sensors can be used to control a robot remotely through the
remote user's ability of seeing what is going on and control the robot on what it
should do next. (Stansbury, 2002). Shown in Figure 7 are different kinds of
sensors (http://www.engineersgarage.com).
Figure 7. Different kinds of sensors
There are specific features one has to think through when choosing a
sensor. These are accuracy, environmental condition, ranges, calibration,
resolution, cost, and the repeatability of the sensors. It can be determined
according to the power or energy supply requirement. Active sensors must have
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a power supply before use while passive sensors do not require a power supply
(engineersgarage.com, 2011). Sensors are either immediate showing (e.g., a
mercury thermometer or electrical meter) or matched with a pointer perhaps by
implication through a simple computerized Analog to Digital converter (A/D),
and a Personal Computer (PC). Sensors are utilized in different applications
such as in pharmaceutics, industry, and mechanical autonomy. With the
specialized advancement, more sensors are fabricated with Micro-ElectronicsMechanic-Systems (MEMS) innovation. This regularly offers the capability of
coming to a much higher affectability (Li, 2008).
Radio Frequency Identification (RFID)
According to Violino (2005), an RFID is a general term to describe a
system that broadcasts a unique serial number of a certain thing or a human
being wirelessly, using radio waves. RFID technology has resemblance to the
bar code identification systems that people see in retail stores every day.
However, one huge difference between the RFID and the bar code technology
is that RFID does not depend on the line-of-sight reading that bar code
scanning needs to function (Beal, 2005).
Well-known in today's society is the use of RFID. It is found almost in
every market including the government, transportation, consumables, hospitals,
retail, and manufacturing, RFID is used to track vehicles, cattle, shipping
containers, tools, and even employees. In some cases, RFID provides
information about the tracked object's condition such as temperature, humidity,
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and precise location. RFID systems involves data-collecting readers and dataproviding transponders, or tags, which are attached to the physical objects to be
tracked. RFID tags are can be purchased as strips, chips, capsules, and can be
embedded in hardware like screws for attachment to nearly any object
(Evanczuk, 2012). Each tag is attached to an antenna that retrieves
electromagnetic energy sent at it from a reader. When it receives the energy,
the tag replies its one-of-a-kind identification number to the reader, allowing
the item to be remotely identified (McIntyre and Albrecht, 2003). Shown in
Figure 8 is an example of an RFID reader and tags (http://www.14core.com).
Figure 8. An RFID reader and tags
VI. Scope and Delimitations
This study aimed to develop a Raspberry Pi laboratory circuit trainer to
help the students of the University of Mindanao in performing laboratory
experiments on general purpose input/output (GPIO), interfacing and data
communications. The study also targets a number of engineering courses
specifically, computer engineering, electronics engineering and electrical
engineering.
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The main single-board computer is the Raspberry Pi 2 model B. In terms
of the GPIO, the pins can only tolerate 3.3 volts compared to Arduino Uno
which can accept 5 volts from various outside devices. Aside from the voltage
tolerance, the Raspberry Pi 2 model B has only 1 PWM output. The Raspberry
Pi 2 excludes an analog-to-digital converter (ADC) which purchased
separately.
VII. Methodology
In this section are contained procedures undertaken for the development
of the device. It includes the research design, consideration of multiple designs
and constraints, design standards, and procedures.
Research Design
The research study was outlined using the structure of applied research.
It involved the application of basic principles about circuits and basic concepts
of computers. The design structure was proven essential for the development of
the trainer.
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Conceptual Framework
The researchers designed a number of laboratory exercises in using the
trainer based on minimum requirements of CHED and the course syllabus as
shown in Figure 1. This is followed by the computer engineering program in
implementing programming and circuit design subjects. Topics covered by the
device are cross-referenced with these guidelines. The researchers designed a
trainer and constructed the main board that contained various circuit modules
suited for the laboratory exercises.
Input
Process
Experiment gathering
from various sources
based on the course
syllabus and or the
CHED Memorandum
Order 13 Series of
2008



GPIO
Interfacing
Data
Communications
Design Constraints




Hardware development


Hardware
Output



Component
gathering
Create circuit
corresponding to
the component
Test functionality
Make into printed
circuit board
Embed into an
enclosure
Raspberry Pi
Laboratory circuit
trainer
Economic
Environmental
Manufacturability
Sustainability
Figure 9. Conceptual framework of the study
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Multiple designs
The researchers considered two designs, Design A and Design B. Both
designs had the same modules and components. Components like resistors, and
transistors were soldered directly into the board. The main difference was
found in the circuit board. In Design A, the components were soldered directly
into the circuit board while in Design B had female pinheaders soldered and the
components were attached later. See Figure 9 for Design A and Figure 10 for
Design B.
Figure 10. Design A
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Figure 11. Design B
The researchers considered the following realistic constraints of the two
proposed designs:
Design Constraints
Economic constraint. Based on the cost analysis shown in Table 1,
Design A and Design B’s cost are almost comparable. However, in the long run
if ever there will be damages to some components, Design A will have to be
dismantled and remade while Design B can be easily replaced with new
components, thus making the latter more economical.
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Table 1.
Costing
Design A
Main Components
1 PCB 15x12
1 Raspberry Pi Kit
10 Female Pinheader
Total
Price
PHP 180
PHP 2,678
PHP 80
PHP 2938
Design B
Main Components
2 PCB 9.5x6.5
1 Raspberry Pi Kit
30 Female Pinheader
Total
Price
PHP 123.5
PHP 2,678.04
PHP 240
PHP 2942
Environmental Constraint. Both designs A and B had a Raspberry Pi 2
Model B as the main computer. Considering that the Raspberry Pi only used 5
volts, 2 amperes direct current electricity, this consumes less electricity
compared to a typical desktop computer. With this, the research helped lessen
the consumption of electricity and led to less use of fossil fuels. Also, the
researchers used little to no hazardous materials in making the circuit trainer.
Manufacturability Constraints. The researchers considered many things
to complete the trainer. This included the physical dimensions, circuit design,
and time consumed. With design A, the circuit components were soldered
directly to the circuit board while design B had pin headers that will be used to
insert the components. Both designs are easy to manufacture but design B is
preferable because of easy component replacement.
Sustainability Constraints. Design A was hard to sustain since all is
wasted when a single component was busted. Since the trainer is to be used by
a lot of students, there is a possibility of items wearing down. The researchers
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came up with a design to make replacement easy. Design B was more
sustainable because of easy component replacement. Since the trainer is to be
used by a lot of students, there is a possibility of items wearing down. The
researchers came with a design that will make replacement easy.
Trade-offs
Table 2.
Constraints summary per design
Constraints
Economical
Environmental
Design A
Somewhat not economical
in the long run because of
non-replaceable
components.
Uses 5 volts 2 amperes
power source.
Manufacturability
Components are directly
soldered to the circuit
board.
Sustainability
Less sustainable in the
long run
Design B
Economical in the long run
because of replaceable
components.
Uses 5 volts 2 amperes
power source.
Components are
removable because of
soldered female
pinheaders.
Easier to sustain because
of easy component
replacement.
Design A was discarded by the researchers since it is not economical
and not easy to sustain as mentioned above. Design B was chosen as it is more
economical and has potential for sustainability.
Design Standards
After, considering the realistic constraints, the researchers opted to pursue
design B and the following industry standards were followed:
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IPC-2221 (Generic Standard on Printed Board Design). This standard
sets up the general needs for the design of organic printed circuit boards (PCBs)
and other forms of part mounting or connecting structures, including personal
computer card form factors. The organic materials may be same, secured, or used
in combination with inert materials; the connections may be on its own, paired, or
with multiple layers.
IPC-6011(Generic Performance Specification for Printed Boards).
This description sets up the general needs for printed circuit boards (PCBs) and
the quality and consistent assurance requirements that must happen for their
acquirement. The purpose of this requirement is to allow the PCB handler and
provider elasticity to create the best processes for the creation and obtaining of
PCBs.
Research Procedure
The study focused on creating a circuit trainer using the Raspberry Pi.
1. At the early stage of the research, the proponents gathered electronic
components that are applicable to the said circuit trainer.
2. Next, they created a circuit corresponding to the component and then
test the functionality.
3. After the functionality test, the circuits were made into a printed
circuit board and the researchers embedded it in a presentable
enclosure. Shown in Figure 12 is the process flow of how the circuit
trainer was made.
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The circuit trainer had several different laboratory exercises followed by
observational questions in order to evaluate student’s progress and learning
regarding the type of experiment performed. The Raspberry laboratory circuit
trainer consisted of 26 electronic components. The researchers had conducted
15 trials per component.
Figure 12. Process Flow for the Development of the Trainer
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Testing Procedure:
1. A sample Python program was generated to be run by the Raspberry
Pi.
2. The component was connected according to correct pinning to the
GPIO pins of the Raspberry Pi.
3. Output was observed and data was collected.
VIII - Findings of the Study
In this section is contained the final design of the trainer and the results
and findings attained from the series of tests conducted to serve the purpose of
the study.
Raspberry Pi Circuit Trainer
Shown in Figure 13 is the enclosure layout of the trainer with base
dimensions of 16 inches by 12.8 inches by 3.9 inches and cover dimension of
15.73 inches by 12.92 inches.
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Figure 13. Trainer enclosure layout and dimensions
Shown in Figure 14 is the schematic designs of all the components in
the trainer.
Figure 14. Schematic designs of the trainer components of the trainer
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Shown in Figure 15 is the final design of the trainer. The researchers
designed a trainer with easy replaceable parts in case a component will not
work. The dimensions of the enclosure of the trainer are 16 inches by 13 inches
by 4 inches with cover of dimensions 16 inches by 13 inches. A 7-inch monitor
is the main display of the circuit trainer.
Figure 15. Final Trainer
Shown in Figure 16 is the back part of the trainer with the AC socket
and the switch for turning on the trainer.
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Figure 16. Final Trainer (Back)
There are two circuit boards as shown in Figure 17. The dimensions of
each board are 9.5 inches by 6.5 inches. The trainer consisted of components
from basic electronics to complicated components like motors and sensors.
Figure 17. Printed Circuit Board
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The trainer has 26 components. It consists of components such as LEDs,
buttons, active buzzer, passive buzzer, 7-segment display, 4-bit 7-segmen
display, RGB LED, dot-matrix display, 74HC595, 16x2 LCD, LED bar graph,
DC motor, servo motor, stepper motor, relay, passive infrared sensor, tilt
switch, photoresistor, thermistor, DHT11, potentiometer, joystick, matrix
keypad, ADXL345 accelerometer and RFID MFRC522. A breadboard, a GPIO
expansion board and an expansion cable were also used. Shown in Figure 18
are the components found in the circuit trainer.
Figure 18. Components of the Trainer
Functionality Test Results
Shown in Table 3 are the results of the test procedures conducted for the
LED display. The objective was to ensure that the lights emitted by the LEDs
were stable. The tabulated data below showed that the testing conducted was
successful.
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Table 3.
Light Emitting Diode (LED)
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 4 are the results of the test procedures conducted for the
Active buzzer module. The objective was to make an active buzzer sound and
ensure that it is functioning properly. The table below indicated that it was
working properly.
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Table 4.
Active Buzzer
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 5 are the results of the test procedures conducted for the
Passive Buzzer. The objective was to make an active buzzer sound and ensure
that it is functioning as it should be. The table below indicated that it was
working properly.
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Table 5.
Passive Buzzer
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 6 are the results of the test procedures conducted for the
Tilt Switch. The objective was to know whether or not the tilt switch worked
by tilting it to a certain angle. The tabulated data indicated that the test conduct
was successful.
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Table 6.
Tilt Switch
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 7 are the results of the test procedures conducted for the
button control. The objective was to know where or not the buttons are
consistent when pressed. The result of the test was successful as shown in the
tabulated data below.
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Table 7.
Button
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 8 are the results of the test procedures conducted for the
Relay. The objective to know where or not the relay works as intended. The
relay produces a sound whenever it opens or closes. The tabulated data below
showed that the testing was successful.
34
Table 8.
Relay
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 9 are the results of the test procedures conducted for the
RGB LED. The objective was to ensure that all three colors of the RGB LED
are okay and worked at is it should. The tabulated data below showed that the
testing was successful.
35
Table 9.
RGB LED
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 10 are the results of the test procedures conducted for
the 7-Segment Display. The objective was to guarantee that the lights emitted
by the nodes of the segment were equally distributed. The tabulated data below
showed the trials conducted which gave a successful result.
36
Table 10.
7-Segment Display
Functional
No. of Trials
Yes
Remarks
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Shown in Table 11 are the results of the test procedures conducted for
the 74HC959. The objective was to ensure that the IC can drive the 7-segment
display and the dot-matrix display. The tabulated data below based the trials
conducted during the testing showed a successful result.
37
Table 11.
74HC595
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 12 are the results of the test procedures conducted for
the 4-digit 7-Segment Display module. The objective was to ensure that all
LED nodes of the display worked. The tabulated data below showed that the
experiment was successful.
38
Table 12.
4-Digit 7-Segment Display
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 13 are the results of the test procedures conducted for
the 16x2 LCD. The objective was to know whether the LCD displayed the
intended output. The data below showed the testing was successful.
39
Table 13.
16x2 LCD
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 14 are the results of the test procedures conducted for
the Matrix Keyboard. The objective was to ensure that all keys were working.
The tabulated data below revealed that the testing was successful.
40
Table 14.
Matrix Keypad
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 15 are the results of the test procedures conducted for
the Ultrasonic Sensor. The objective was to ensure that the sensor
communicates correctly with the Raspberry Pi. The result of testing was
successful based on the tabulated data below.
41
Table 15.
Ultrasonic Sensor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 16 are the results of the test procedures conducted for
the Temperature & Humidity Sensor – DHT-11. The objective was to ensure
the interconnection of the GPIO and the sensor was functional. The data below
showed that the testing was successful.
42
Table 16.
DHT11
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 17 are the results of the test procedures conducted for
the Dot-Matrix Display. The objective was to ensure that all lights are
functional and lights emitted were equally distributed. The tabulated data
below showed the testing was successful.
43
Table 17.
Dot-Matrix Display
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 18 are the results of the test procedures conducted for
the Photoresistor. The objective was to measure the variable resistance based
on the light intensity. The tabulated data below showed the testing was
successful.
44
Table 18.
Photoresistor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 19 are the results of the test procedures conducted for
the Thermistor module. The objective was to measure the variable resistance
based on temperature. As shown in data below, the testing was successful.
45
Table 19.
Thermistor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 20 are the results of the test procedures conducted for
the LED Bar Graph. The objective was to ensure that all light nodes of the LED
Bar Graph are functioning. The tabulated data below showed the testing was
successful.
46
Table 20.
LED Bar Graph
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
Shown in Table 21 are the results of the test procedures conducted for
the DC motor module. The objective was to ensure that the motor turned
according to the state commanded by the Raspberry Pi. The states of the DC
47
motor include forward, reverse, acceleration, deceleration and stop. The testing
result was successful as shown in the data below.
Table 21.
DC Motor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
48
Shown in Table 22 are the results of the test procedures conducted for
the stepper motor. The objective was to ensure the motor turns according to the
Pi’s command. The tabulated data below show that the testing was successful.
Table 22.
Stepper Motor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
49
Shown in Table 23 are the results of the test procedures conducted for
the accelerometer ADXL345. The objective was to ensure that the
accelerometer worked and the output changed depending on the axis of the
component. The tabulated data below showed that the testing was successful.
Table 23.
ADXL345
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
50
Shown in Table 24 are the results of the test procedures conducted for
the PS2 Joystick. The objective was to ensure that all states of the joystick, left,
right, up, and down, were working properly. The table below showed that the
testing conducted was successful.
Table 24.
PS2 Joystick
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
51
Shown in Table 25 are the results of the test procedures conducted for
the Potentiometer. The objective was to ensure that the output of the
potentiometer changed whenever the knob is turned. The tabulated data below
showed that the program used and the device were functional and stable.
Table 25.
Potentiometer
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
52
Shown in Table 26 are the results of the test procedures conducted for
the Passive Infrared (PIR) Sensor. The objective was to know whether or not
the PIR sensor detected motion. The tabulated data below showed that the
program used and the device was functional and stable.
Table 26.
Passive Infrared (PIR) Sensor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
53
Shown in Table 27 are the results of the test procedures conducted for
the Servo motor. The objective was to ensure that the servo motor turns
according to the state command of the Raspberry Pi, i.e. 0 degrees, 90 degrees,
and 180 degrees. The tabulated data below show that the testing was functional
and stable.
Table 27.
Servo Motor
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
54
Shown in Table 28 are the results of the test procedures conducted for
the RFID. The objective was to ensure that there was data communication
between the RFID card and the Raspberry Pi. The tabulated data below showed
the testing was functional and stable.
Table 28.
RFID
Functional
No. of Trials
Yes
1

Successful
2

Successful
3

Successful
4

Successful
5

Successful
6

Successful
7

Successful
8

Successful
9

Successful
10

Successful
11

Successful
12

Successful
13

Successful
14

Successful
15

Successful
No
Remarks
55
IX - Conclusions
Based on the findings of the study, the researchers came up with the
following conclusions:
1. The trainer can perform different kinds of laboratory experiments.
The components which were used in the trainer are made up of basic
electronic circuit components up to full modules; this what makes
these activities important in studying.
2. All of the components used are functioning well based on the
component datasheet and online sources. The components tested are
GPIO like LEDs and buttons, interfacing like motors, and data
communications like RFID.
X - Recommendations
Based on the results of the tests conducted by the researchers and the
conclusion drawn, the following are recommended:
1. Further studies can be done to improve the trainer. Since the
Raspberry Pi is a computer itself, future researchers can implement
other computer functions to the components used on the trainer. One
can use web-based servers to control the components wirelessly.
2. Future researchers can upgrade the Raspberry Pi if there is a newer
model available.
3. The LCD monitor could be upgraded to a larger monitor.
56
XI. References
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2016 from http://www.spychips.com/what-is-rfid.html.
Beal, V. (2005). All About RFID. Retrieved February 21, 2016 from
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Bray, J. (2015, October 5). Raspberry Pi 2 Model B review: Still the best
microcomputer.
Retrieved
January
4,
2016
from
http://www.alphr.com/raspberry-pi/raspberry-pi-2.
Calin, D. (2015, March). Raspberry Pi 2 OS Selection For Designers And
Developers.
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February
21,
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from
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Cuzon, M. et al (2015, April). Development of an Arduino-Based
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elinux.org (2015, July 3). RPi Low-level peripherals. Retrieved February 20,
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57
Evanczuk, S. (2012, January 5). Fundamentals of RFID communications.
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from
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58
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from
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from
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59
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